# Carbon fiber plenum



## Forty-six and 2 (Jan 21, 2007)

I am going to be building a short runner intake pretty soon, and I am considering making the plenum out of carbon fiber, and possibly using fiberglass if it can handle the pressure. 
I will make a mold for the plenum and use a 1/2" piece of aluminum as the base for the runners. The plenum will be bolted to the aluminum. I will most likely use a piece of aluminum in the plenum portion where it will be bolted, to insure that it won't crack when torqued to the base. 
The main question is, would using 3 to 4 layers of fiber glass cloth as a base for the 3 to 4 layers of CF with stand the internal pressure? I plan to run up to 30 psi. The reason for the fiber glass would be to cut down on the cost of carbon. It all would be vacuum bagged, in order to compact the material and remove excess resin. 
Let me hear your thoughts and opinions on this idea.










_Modified by Forty-six and 2 at 7:28 PM 7-23-2009_


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## SpeedWorksAutoTuning (Sep 8, 2008)

*Re: Carbon fiber plenum (Forty-six and 2)*

I had a friend of mine that built a composite intake, and it held up fine until his car backfired through the intake. So, do like the manufacturers do on their composite manis, and make a way to vent excess pressure just in case.


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (SpeedWorksAutoTuning)*

I just read about that problem. I am looking into a pressure relief valve. I haven't really found any that would work yet. Do you have any pictures or info on how your friends mani was made?


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (Forty-six and 2)*

After thinking about it more overnight, I think the beast way would to make a plenum out of foam as a postive mold, then gelcoat and fiberglass a two piece negative mold. One the neagtive is made, make the two halfs of the plenum, then wrap over the seams to make them one. 
The reason for doing this, is to make a plenum that has nearly zero turbulant air flow, and not be limited to only basic shape constrants, as you have to with aluminum. 
I used to work for a foam packaging company that I will be able to source the proper foam from. I will use aluminum runners that will be bonded to the plenum. I an considering bonding the inlet of the runner into the plenum, and using a vband clamp to attach it to the lower portion as it leaves the plenum. The reason for this would be to make sure if there ever were a problem with the plenum, I would be able to remove it easily and make a new one. My only concern is that the vbands may leak. I have never used a vband clamp before, so I have idea if they become leaky over time.
Does anyone know where I could find a small vband flange and clamp? 
Any input is appreciated.

Also, was size tubing should be used for the runners on a 16v? I have the flange cut already, but since the ports are oval, I'm not sure what to use. Ross machine racing have some nice oval tubing, but it smaller than the ports on the factory flange.


_Modified by Forty-six and 2 at 6:57 AM 7-24-2009_


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## SpeedWorksAutoTuning (Sep 8, 2008)

*Re: Carbon fiber plenum (Forty-six and 2)*

Thats easy!
http://www.clampco.com/product...t.asp
Was in my favorites.

I dont remember what he did for the intake, but he integrated some sort of pressure relief valve. I have seen a trap door kind of thing with a high tension spring keeping it closed on some factory manis though.


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## Dub Doctor (Jul 17, 2009)

*Re: Carbon fiber plenum (SpeedWorksAutoTuning)*

Make sure you anodize anywhere aluminum comes in contact with carbon fiber or it will corrode over time. I've made one before for a GM ecotec motor. PM me if you want details on construction.


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (Dub Doctor)*

I was thinking of using a single layer of fiber glass to keep the carbon from touching the aluminum, but anodizing is a great idea.
Right now I am trying to come up with a good design. Something to opitmize the air fow to all cylinders. I don't know how good this one is, but would like to hear your opinions.


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## SpeedWorksAutoTuning (Sep 8, 2008)

i thought youd want the plenum to taper towards the farthest cylinder


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## BSD (Jul 8, 2008)

If you use syrofoam, don't put fiberglass straight over foam.. fiberglass eats it.
Steve-


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## Forty-six and 2 (Jan 21, 2007)

*Re: (SpeedWorksAutoTuning)*

I may just go with a dual plenum design. I am really just brain storming for something that will work right now. I have been searching for something soild to work towards. I have been seeing a ton of conflicting info about plenum design and even velocity stacks. I am not sure whats right, so if any of you know anything about proper design I would love to hear about it. I build one manifold a while back for a xflow head, and used velocity stack on the inside of the plenum, but never dynoed it to seeing it made any gains. I have been seeing that most intake designs here on the tex are flawed, and really just look nice without having real gains. 
This design seems to be well thought out.








































I think I will go in this direction.



_Modified by Forty-six and 2 at 4:20 PM 7-27-2009_


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## SpeedWorksAutoTuning (Sep 8, 2008)

I use resin that doesnt eat styrofoam, I forget what its called....or you can just paint over the foam with a latex paint.


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## ABA Scirocco (May 30, 2001)

*Re: (SpeedWorksAutoTuning)*

Polyester or vinylester resins will eat styrofoam but the epoxy resins normally used with CF do not. FWIW, I've used Polyester resins over styrofoam, some type of physical barrier, like latex paint, between foam and resin is required. I used drywall joint compound because it'll soften up in warm water so you can rinse it out of the finished part and because it sands well so I could use it to refine the shaped.




_Modified by ABA Scirocco at 8:31 PM 7-27-2009_


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## SpeedWorksAutoTuning (Sep 8, 2008)

*Re: (ABA Scirocco)*

^what he said


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## the_q_jet (Mar 19, 2005)

*FV-QR*

gonna be SICK!


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## Dub Doctor (Jul 17, 2009)

*Re: FV-QR (the_q_jet)*

Does that have nuts/bolts INSIDE of the plenum? Brave... cool design though... Never seen one with the flanges cut out of carbon. The benefit of a composite manifold hangs higher in heat transfer than weight. Can't wait to see what you come up with.. I'd love to make one for the VR.


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## fastmaxxcooper (Sep 25, 2003)

*Re: FV-QR (Dub Doctor)*

as for pressure relief you should look into rupture discs! they are a one time use, replaceable. so no valve to leak. they extremely consistent. you just need to install them in the right direction! small and low enough pressure for your application! http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
http://www.bsbsystems.com/Rupt....html


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## Dub Doctor (Jul 17, 2009)

*Re: FV-QR (fastmaxxcooper)*

I'm not trying to contradict anybody, but you shouldn't have to worry about a pressure relief valve unless your design includes an area where fuel can puddle. Even then a backfire would be rare and would blow an aluminum or carbon fiber intake manifold apart all the same.


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## Forty-six and 2 (Jan 21, 2007)

*Re: FV-QR (fastmaxxcooper)*

I was looking at these yesterday.
http://www.wilsonmanifolds.com...&p=56
I founds some better ones but didn't save the link.







They were spring loaded, so you didn't have to replace them if pressure was relieved.
The drywall compound is a great idea! Thanks. Now I will have to start figuring out how to setup the molds properly. Should I use something soild as the flange then wrap over it? I was thinking either a piece of 1/4" aluminum, or posibly some sort of absorbant wood, maybe? I don't really want solid CF. I am not brave enough for that. I will not be using bolts on the insides of the plenum. I will just make sure to attach the plenums together with plenty of wraps. 
Also, should there be and kind of baffel near the inlet of the first plenums ports to the second? Maybe to forces the air to "swirl" around the plenum into the runners?
Oh, and a VR intake WILL come later on.









Found it.
http://store.trackerdesigns.co...TMRCI


_Modified by Forty-six and 2 at 6:49 AM 7-28-2009_


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## SpeedWorksAutoTuning (Sep 8, 2008)

*Re: FV-QR (Forty-six and 2)*

online metals sells carbon fiber in panel, rods, tubes, etc....


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## Forty-six and 2 (Jan 21, 2007)

*Re: FV-QR (SpeedWorksAutoTuning)*

They are pretty expensive. I usually buy all of my aluminum from them for their cut to size options and good pricing, but that is some expensive material.








I was just looking through different carbon fabric, and kevlar caught my eye. Do you know much about it? It is nearly half the cost, which is a major plus. I will still use carbon also, but if kevlar can cover aluminum without the corrosion problem, it may be the better choice for covering flanges and other aluminum bits that will have to be integrated into the manifold It seems to be just as strong and will work better for bulking up certain parts of the design.


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## l88m22vette (Mar 2, 2006)

*Re: Carbon fiber plenum (Forty-six and 2)*

The dual-plenum design shown is basically identical to the Dahlback IM for the 1.8T, which proved to be more restrictive than a simple tapered single-plenum (see Monster 007 or SEM IMs)


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (l88m22vette)*

The Dahlback design maybe flawed, but I am sure the basic design idea has been proven to be efficient.








Audi R8 LaMans engines


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## ABA Scirocco (May 30, 2001)

*Re: Carbon fiber plenum (Forty-six and 2)*

I could see a design like that being effective especially within narrow rev bands but properly executing and tuning it would be extremely tricky. My reason for saying that is that the size of slots or holes separating the two halves of the plenum are critical, too big and it's no different than having a single plenum, too small and it's needlessly restrictive. The tricky bit comes in because whatever size you choose will be optimal for only one air flow rate and discovering what gives you best performance for the type of driving/racing you do would likely require a lot of tweaking and experimentation.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Carbon fiber plenum (ABA Scirocco)*

If possible, could you guys post up any links, or reference material regarding intake manifold design?
Am I correct in thinking that a split plenum design as pictured above, is really oriented to a forced induction setup, and would not be needed (or even beneficial) to a naturally aspirated motor?


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## Issam Abed (Feb 12, 2004)

*Re: Carbon fiber plenum (Forty-six and 2)*


_Quote, originally posted by *Forty-six and 2* »_The Dahlback design maybe flawed, but I am sure the basic design idea has been proven to be efficient.

Not this again...
You cant compare Audi Motorsport to ever known application in manifold design.
Motorsport = restrictions and rules = designs to maximise EFFICIENCY not PERFORMANCE.
The dual slot manifold = a POS...I know because the Dahlback manifold that was tested was mine.


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (Issam Abed)*

So are there any dual plenum manifolds that work well?


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (Jettaboy1884)*

http://www.bufkinengineering.c...s.htm
http://www.jasperintegration.c....html
some info

_Quote, originally posted by *Issam Abed* »_
Not this again...
You cant compare Audi Motorsport to ever known application in manifold design.
Motorsport = restrictions and rules = designs to maximise EFFICIENCY not PERFORMANCE.
The dual slot manifold = a POS...I know because the Dahlback manifold that was tested was mine.










I find it hard to believe that every dual plenum design is restrictive. I see how it could easily be restrictive if not designed properly. I actually have been search for more than an exterior picture, in hopes to see what the problem could be. If you can, could yu give me some specs on your manifold? I am in no way belittling you or you design skills, just trying to figure out the proper theory to how to make these work efficiently. 
I have been doing a ton of searching trying to figure out a true even flow manifold, and I am really not a believe in the tapered plenum idea. I actually think opposite of true. The last runner doesn't get the least amount of air, but the most. It you think of fluid flow through a plenum, the pressurized fluid will flow to the back the plenum then start flowing out of the furthest runner the most. The runners from there forward, to the throttle body, will then progressively start flow more until it makes it to the first runner, which will flow the least. The fluid will quickly flow past the first runner untill it hit the end cap then will be forced out of the runners. The closet to the end, the more flow. So untill you create a plenum that has equal entering flow, the flow to the runners will not be equal. That is the reason for the dual plenum design. It definitely has to be designed properly to has it work as planned. The main thing that has to be figured is the slot dividing the two plenums. That is the key to maximum flow.
So how should that be figured?
_Modified by Forty-six and 2 at 1:50 PM 7-31-2009_


_Modified by Forty-six and 2 at 4:47 PM 7-31-2009_


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## Levi20AE (Feb 16, 2005)

*Re: Carbon fiber plenum (Forty-six and 2)*

http://www.jasperintegration.com/navi.html
It's not carbon fiber but it is a dual plenum manifold.
I have a few AEB manifolds that i have cut the factory plenums off of to use the runners. I plan to make one manifold using the Jasper Integration kit and another with a large tapered plenum. I saw really good gains after making the first single tapered manifold for a small port head with a stock turbo, but after seeing lots of duel plenum designs in racing i would like to try on out.
Here are few pictures for ideas...
















































































http://****************.com/smile/emthup.gif


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (Levi20AE)*

I was looking at that site a few days ago, and he has a section on the concept behind the design and he say the slot between the two plenums should be 110% of the throttle body opening. I am not fully understanding what he means by this. The VR6 throttle body is a little under 3" in diameter, so how does that translate into the size of the slot needed? 
It also looks like an oval main plenum is better that a round one. 


_Modified by Forty-six and 2 at 4:53 PM 7-31-2009_


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## the_q_jet (Mar 19, 2005)

*FV-QR*

the total area of the TB vs the total area of the slot so if say the VR throttle plate is 2.75" diameter.
throttle plate area= 5.9"
then the slot area needs to be 6.49"


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## Issam Abed (Feb 12, 2004)

*Re: Carbon fiber plenum (Forty-six and 2)*


_Quote, originally posted by *Forty-six and 2* »_
I find it hard to believe that every dual plenum design is restrictive. I see how it could easily be restrictive if not designed properly.

Certain racing bodies have limitations...
The manifold you posted up is based around WRC regulations.The end goal was to have a manifold that will distribute air EVENLY across each runner.
The Dahlback/Lemans manifold did a good job of this BUT again WRC has power/torque restrictions.The goal of said manifold is not to increase power but to make flow even.Every single 3rd party user that has gone out there and bought a manifold and done back to back dyno testing has confirmed that there is no power to be gained from the manifold.
I am not sure what data you would like but there is this thread which has LOADS of information
http://forums.vwvortex.com/zerothread?id=3098525


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (Issam Abed)*

I saw the original thread that all of those charts were quoted from, but my computer was acting a little wierd, so a 1/4 of the page was missing. 
You may have convinced me not to use the dual plenum, but I am still on the search for a proper equal flow design. A still don't believe a tapered plenum is the answer. 
I have a few ideas to run by you. I will have to make a few drawing or find a good example to describe my thoughts.
I appreciate you imput.

Something like this.
















I would use velocity stacks, and shape the plenum differently, but the basic idea. A 90* from the runner enty.



_Modified by Forty-six and 2 at 6:59 AM 8-1-2009_


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## ABA Scirocco (May 30, 2001)

*Re: Carbon fiber plenum (Forty-six and 2)*


_Quote, originally posted by *Forty-six and 2* »_
I find it hard to believe that every dual plenum design is restrictive. I see how it could easily be restrictive if not designed properly.

For a dual plenum manifold to do what it's designed to do, the slots separating the two halves of the plenum NEED to be at least somewhat restrictive, if there's no pressure drop between the two halves then it's equivalent to a single plenum manifold.
Obviously, we'd like that pressure drop to be a small as can be and still get the job done, unfortunately the pressure drop isn't constant, it varies with the square of the air flow so a design with an optimal pressure drop at at 8000rpm WOT would be complete ineffective at 4000rpm and conversely a design that's optimal at 4000rpm WOT would be very restrictive at 8000 rpm WOT, that's the reason I said they'd be tricky to tune.
Any way you look at these manifolds, there's a compromise being made. What I think Issam was getting at, is that within the confines of a racing application and the rules that govern them, these compromises sometimes make sense but in a broader application, it ain't necessarily (or even usually) so.


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (ABA Scirocco)*

What would be the best design for as even as possible flow, but nonrestrictive as the dual plenum design? Simple physics tell me that a tapered plenum is not the answer. I think inlet placement would be on the right track. The last manifold I pictures I posted seem to be in the right direction. I don't think slapping a throttle body at one end of the plenum will create an equal flow, but setting it up an angle 90* angle to the runners may be ideal, rather than parallel. The air should flow into and distribute itself more evenly that way. At least that is my theory. I wish I had Solid works to build and test it.
I have also read that placing the velocity stack at a raised distance of 1/2 the depth of the plenum is the best. Is there any truth to that? Would making the runners as long as possible be optimal? Longer runners, of couse pulse calculated, gives you better low end torque, and the turbo naturally takes care of the top end. I would think using the longest runners that you bay can fit, would create a better torque curve. 


_Modified by Forty-six and 2 at 5:03 PM 8-1-2009_


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## gruppe5 (May 10, 2003)

*Re: Carbon fiber plenum (ABA Scirocco)*

"For a dual plenum manifold to do what it's designed to do, the slots separating the two halves of the plenum NEED to be at least somewhat restrictive, if there's no pressure drop between the two halves then it's equivalent to a single plenum manifold. "

Thats the point. If you have no restriction with equal area between the throttle body and the slot you will have even airflow. All thats happening is redirection or reshaping of the airflow, it comes out of the slot looking like a smooth, flat and wide stream of water kind of like those high end faucets.


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (gruppe5)*

I now completely understand that the restriction is what makes it work properly. It's a sacrifice of flow for even flow. 
Is there a certain angled entry or plenum shape that will optimize flow to all runners when using a single plenum?

I think that this may be a pretty good design. Because of the angle of entry and the wide open entry taper, the air should flow in and spread out before it hits the end of the plenum. It should, in theory, create close to equal flow across the runners. I also believe a 90* entry angle from the runners will allow the air to naturally distribute throughout the plenum. Minor changes may yield better results.












_Modified by Forty-six and 2 at 8:46 AM 8-3-2009_


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## ibanezplayer (Sep 18, 2006)

*Re: Carbon fiber plenum (Forty-six and 2)*


_Quote, originally posted by *Forty-six and 2* »_
I have also read that placing the velocity stack at a raised distance of 1/2 the depth of the plenum is the best. Is there any truth to that? Would making the runners as long as possible be optimal? Longer runners, of couse pulse calculated, gives you better low end torque, and the turbo naturally takes care of the top end. I would think using the longest runners that you bay can fit, would create a better torque curve. _Modified by Forty-six and 2 at 5:03 PM 8-1-2009_

Well, unfortunately, with all things like this, it depends. The sharper, and more pronounced you make the transition from plenum - runner the stronger the pulse tuning. Essentially, a tube in the open air would create the strongest pulse. Obviously this isn't practical, but, within the plenum you want as much area around the inlet as possible, so you raise the inlet off the floor of the plenum, and leave a good gap from all of the sidewalls. 
Secondly, the aluminum - carbon action probably won't be a concern for you. What sort of aluminum are you using? How are you bonding the two?

EDIT: Also, I think you are worrying too much about an exploding intake...When is the last time your car backfired? 




_Modified by ibanezplayer at 12:23 AM 8-10-2009_


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## ftwelder (Feb 27, 2008)

This is a cool project, keep us posted!


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## Forty-six and 2 (Jan 21, 2007)

*Re: Carbon fiber plenum (ibanezplayer)*

I was planning on 6061 aluminum. I really need to find someone that would be willing yo cut a intake flange for me. I just want a cut out of the gasket. Probably 5/8" thick. I figure after welding runners and injector bungs to it I will have up to an 1/8" to remove the distortion, although I will do my best to minimize it.
I am not sure of the best method to attach the carbon to the aluminum. I have read up on it yet. All I know is there needs to be some sort of buffer between the two. A have heard a single layer of fiberglass works, or a thick layer of resin, and as mentioned in this thread, anodizing. I will definitely research it further, and most likely test a few methods out an scrap. 
The reason for the back firing concern is, I will be running mega-squirt, so I don't know if while tuning it a back fire may occur. I know that it isn't common, but it could only take one to ruin it. I am not positive it I will be putting a relief in it, but we will see.
I have already made my fiberglass mold, so I will be ordering the rest of the materials sometime this week. 
It anyone could cut me a flange I would greatly appreciate it.
Frank, are you capable of something like that? 




_Modified by Forty-six and 2 at 2:03 PM 8-10-2009_


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## A4racing (Jun 13, 2006)

*Re: Carbon fiber plenum (Forty-six and 2)*

there is this from aer racing engines that looks interesting, I am thinking of doing something similar for my a4


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## PeOpLeG60T (Jul 5, 2004)

pretty interesting thread , subscribed !!!
i like the dual plenum idea but the other one in translucent 3D drawing is pretty interesting , air swirling from endcap to endcap isn't directed rigth into a runner , its just spinning in front of all of them , rising some stacks would be cool too.
this carbon fiber intake manifold do look like a million bucks , really nice part ! 
hey can we have a shot of the mold ?


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## Forty-six and 2 (Jan 21, 2007)

*Re: (PeOpLeG60T)*


_Quote, originally posted by *PeOpLeG60T* »_
hey can we have a shot of the mold ? 

Sorry thats the secret part. Especially in the fab forum. I have a finished revised mold for the plenum, and finished one for the velocity stack. I have them waxed and ready to spray the pva. I am in the middle of building a curing box. Once it's setup, I will do a test run with fg, to make sure everything lines up and also to figure out the best places to make my cuts. I have decided to run a well shaped single plenum design. Just a few weeks and i will be able to have something to hold. I can't wait to see it.


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## PeOpLeG60T (Jul 5, 2004)

hehe okay ! i've worked into a fiberglass shop before . we were making ambulance tops and parts for some of Bombardier's ski hill traktors equipments . vacuum injection and manual FG. always been interested in designing molds myself... only molds i've done yet are on funky old food in the fridge...


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## pursuit99 (Apr 3, 2009)

Sorry if this is a bit off topic, an idea for equal cylinder air flow though
Has anyone made an intake like headers? Using equal length runners and proper merge collectors...
What I was thinking was even just splitting into two runners and running each of those into the middle of their own plenum over two cylinders. I can exercise my master paint skills if that doesn't explain it well
Would that concept work or am I just a nut?


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## PeOpLeG60T (Jul 5, 2004)

*Re: (pursuit99)*

http://i658.photobucket.com/al...i.jpg
Corolla
http://www.familycar.com/RoadT...e.jpg 
i've seen tihs before but in order to not affect air flow i think you'd need to have your runners bent because airflow wouldnt like junction points and welds if the thing aint 120% perfect i guess. it would make you long runners and what about the plennum ? and i would be worried about the merge collector taking slightly diffrent amounts of flow in every cylinder if your'e turboing it out since you blowin in. if there is a single slight flaw in the angle the air arrives in and in the aerodynamics of the collector .

yes sure it can be done , you could do whatever goes into your imagination as long as there are runners and a tB .... now for being performant its different. Notice that this design has been made for show. but i'd like to know more about the numbers , im curious

_Modified by PeOpLeG60T at 3:29 PM 2-25-2010_

_Modified by PeOpLeG60T at 3:31 PM 2-25-2010_


_Modified by PeOpLeG60T at 3:33 PM 2-25-2010_


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## GREASE-MONKEY (Nov 22, 2006)

The biggest issue I have is what resin to use to stand up to the heatand vibration. If anyone could shed some light on this or rec sone products that would be helpful.


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## nothing-leaves-stock (Mar 1, 2005)

*Re: (GREASE-MONKEY)*

sorry to thread jack but is anyone making a 16v flanged full carbon intake? if so IM me with info and prices
thanks, josh


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## Forty-six and 2 (Jan 21, 2007)

*Re: (GREASE-MONKEY)*


_Quote, originally posted by *GREASE-MONKEY* »_The biggest issue I have is what resin to use to stand up to the heatand vibration. If anyone could shed some light on this or rec sone products that would be helpful. 

I bought some resin that handles up to 550*. Suposedly it gets stronger with heat. I with have to take a look at the brand and type later today.

_Quote, originally posted by *nothing-leaves-stock* »_sorry to thread jack but is anyone making a 16v flanged full carbon intake? if so IM me with info and prices
thanks, josh

I have thought of this, but for time reasons I decided against it. I still would like to persue it though. What exactly are you thinking of? Injector bungs, and "stub" runners?


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## nothing-leaves-stock (Mar 1, 2005)

*Re: (Forty-six and 2)*

i want a carbon fiber SRI for a 16v turbo with TB under it in the center. kind of hidden


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## Forty-six and 2 (Jan 21, 2007)

*Re: (nothing-leaves-stock)*

I am going to lay the first few layers of carbon in the molds on Thursday. I will post with the outcome. It you are truely interested, am would want me to make something for you, i can possible take on the project. Do you already have the full design planned?


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## nothing-leaves-stock (Mar 1, 2005)

*Re: (Forty-six and 2)*

no design plan. 
yes i'm 100% serious
let me know


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## Forty-six and 2 (Jan 21, 2007)

*Re: (nothing-leaves-stock)*

IM sent


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## GREASE-MONKEY (Nov 22, 2006)

*Re: (Forty-six and 2)*

If you. You could pm me the name if the resin that would be great


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## Forty-six and 2 (Jan 21, 2007)

*Re: (GREASE-MONKEY)*

The beginingof the plenum. The first two layers of the one half of the plenum. This part is nowhere near a finished product.
























The mold worked flawlessly. Wax and pva released perfected.


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## nothing-leaves-stock (Mar 1, 2005)

*Re: (Forty-six and 2)*

good deal...hurry up and get it done...i want it


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## Forty-six and 2 (Jan 21, 2007)

*Re: (nothing-leaves-stock)*








Changing your mind about the center tb?


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## nothing-leaves-stock (Mar 1, 2005)

*Re: (Forty-six and 2)*

yea. easier for you, since its made...


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## Forty-six and 2 (Jan 21, 2007)

*Re: (nothing-leaves-stock)*

Yeah, making those molds sucked.... 
IM sent


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## Forty-six and 2 (Jan 21, 2007)

*Re: (Forty-six and 2)*










The first half of a velocity stack. Needs to be trimmed and sanded still. Unfortunately it f'ed my mold when releasing it.







I have to repair it to pull the rest.


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## PeOpLeG60T (Jul 5, 2004)

sad for the mold ! woops ! its gonna be killer ! cant wait to see the flange !!! and also really really interested in seeing the assembling. i can figure out how to assemble the halves together by wrapping cf around them but the rest i wanna see!


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## ABA Scirocco (May 30, 2001)

*Re: (Forty-six and 2)*

I like using styrofoam to make forms with I'm making complex shapes with fiber glass. You could use dense styrofoam to make a plug the same shape as the inside of the velocity stack, lay up the CF over the plug and once epoxy has set, dissolve out the foam with acetone or brake cleaner, that'll give you a velocity stack with a perfect internal surface and no seams. The big down side of this technique is, of course, you can't reuse the plug so, you'd need to make one for each stack.




_Modified by ABA Scirocco at 8:56 PM 3-22-2010_


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## Forty-six and 2 (Jan 21, 2007)

*Re: (ABA Scirocco)*

I have thought of that, but I have to cure the resin at 200*+. I would be really pissed off if my plugs would melt and waste the carbon and resin.


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## ABA Scirocco (May 30, 2001)

*Re: (Forty-six and 2)*

I'm pretty sure 200°+ would be a problem with the foam. Maybe next time you're curing something, toss a piece of foam into the oven just to see what happens, if by some miracle it's stable at curing temperatures then you'd have a powerful new technique at your disposal and if doesn't work, you've lost nothing in the attempt.


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## nothing-leaves-stock (Mar 1, 2005)

*Re: (ABA Scirocco)*

anything?


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## TheBurninator (Jan 7, 2009)

nothing-leaves-stock said:


> anything?


 Not really an update but I saw this plenum in person a couple weeks ago:


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## nothing-leaves-stock (Mar 1, 2005)

hmmmmmmmm....


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## Forty-six and 2 (Jan 21, 2007)

Life has been kicking my ass these lat few months. I will get back to it soon, hopefully.


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## GTijoejoe (Oct 6, 2001)

This is looking really good, curious how this is going to be put together with flanges to the head.


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## Scullies (Apr 17, 2012)

Did you ever make this cf plenum? 
How many layers of cf did you use?


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## [email protected] (Jan 13, 2005)

Forty-six and 2 said:


> This design seems to be well thought out.
> 
> 
> 
> ...



I personally took these photos while staying with a Norwegian Cosworth tuner back in January 2006.    I'll see if there are any more in the stash that might inspire exchange of ideas, etc. 

P.S. If your screen name refers to the TOOL song, you rock.








:thumbup:


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## Scullies (Apr 17, 2012)

That intake looks like its aluminim thats wrapped with carbon fiber. It might just be the pictures but it looks like there are welds at the joints that are covered with carbon.

I am busy shapeing a plug at the moment. I'm going the route of the Integrated Eng. & Xcessive plenum. So the carbon fiber plenum with get bolted up to a flange on some large port runners, or even small port if you wish.
I think 4 layers of carbon fiber will be enough


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## Scullies (Apr 17, 2012)

[email protected] said:


> P.S. If your screen name refers to the TOOL song, you rock.


Screen name is a nic name from school days thats just stuck. 
I haven't heard the Tool song, which one you talking about?


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## DMVDUB (Jan 11, 2010)

sick mani!

46 & 2


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## sdezego (Apr 23, 2004)

Scullies said:


> Screen name is a nic name from school days thats just stuck.
> I haven't heard the Tool song, which one you talking about?


He is talking about the Orig Poster...

...and yes, 46 & 2 comes from the Tool song. Unfortunately, "Matt" has been off the radar and this was for a Corrado project that got scrapped/parted. Unfortunate, as there were aspects that were highly original. I ma sure he will be back at it someday. :beer:


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## Forty-six and 2 (Jan 21, 2007)

sdezego said:


> He is talking about the Orig Poster...
> 
> ...and yes, 46 & 2 comes from the Tool song. Unfortunately, "Matt" has been off the radar and this was for a Corrado project that got scrapped/parted. Unfortunate, as there were aspects that were highly original. I ma sure he will be back at it someday. :beer:



Thanks Shawn!:beer: I am back at it, except with a TT this round.  I am trying to wrap up my body work portion of the build right now. Once its painted, I will get back to the motor. I am going to stick with my 20/20 setup. I have been debating on getting my plans back together for the carbon manifold...

I personally planned on 9-12 layers of 6oz. fabric, with carbon tow wrapping between every 3rd layer. Of course high temp resin. 


And yes, my sn is in reference to the Tool song.:beer:


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## sdezego (Apr 23, 2004)

:beer:


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## Scullies (Apr 17, 2012)

Forty-six and 2 said:


> Thanks Shawn!:beer: I am back at it, except with a TT this round.  I am trying to wrap up my body work portion of the build right now. Once its painted, I will get back to the motor. I am going to stick with my 20/20 setup. I have been debating on getting my plans back together for the carbon manifold...
> 
> I personally planned on 9-12 layers of 6oz. fabric, with carbon tow wrapping between every 3rd layer. Of course high temp resin.
> 
> ...


That sounds like a lot of lay up, I build small fiberglass boats and we use 9 layers of various mats, 300, 450 and 600 woven.
I have never worked with carbon fiber but since it's stronger than fiberglass I was thinking 3 / 4 layers.
Have you ever done any pressure testing on carbon fiber. I see they make carbon fiber cylinders for compressed air. Would like to know what lay up they use in those cylinders as they are high pressure.


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## polov8 (Apr 14, 2004)

Inspired by this thread, I had a bit of a google. Not alot out there really! Checked out one of these at the Autosport show earlier this year, very nice, very spendy: 










http://www.reverie.ltd.uk/product_detail.php?group=A PLEN&part_code=R01SE0485

Google showed up this: 










http://www.mct-carbon.com/projects11.php


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## Brian.G (May 8, 2010)

The top manifold there is made in a two piece steel tool.

A slightly smaller plug is first made from rubber. Over this plug they pull an inflatable bladder. Onto this bladder the prepreg is laid in a particular way. The whole lot is placed in the bottom tool and top tool fitted. 

The bladder bag gathered and is pressurized from the open throttle body end. 

The steel tools have ports inside to heat tool walls. These ports are connected to a steam line to heat tool to around 130degc.

There is a small runner around part on the parting line faces, with gates out to it to draw off any excess resin. This runner may or may not be connected to a vac line - most times not.

The tool and part is cooked with steam running inside tool for about 25min. 

Once done, air is turned off, tool opened and the part is removed. The rubber plug and bag are pulled out through the large hole once itb window has been cnc cut.

Sometimes, the prepreg is wrapped off the plug, plug removed, and it knitted up together again around bag carefully(prepreg holds its shape well.) This saves removing the plug if there is no access, the bag is just ripped out.

The above is dear, because steel tooling is dear to build, and when the production numbers are small, it can only but be reflected in final part cost.

The tb mount can be then tidied, cnc'd round internally, or not, and the alloy bonded in.

The above is how all composite parts are made really, manifolds, sail masts, f1 parts, bikes, etc.

Brian,


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## ny_fam (Apr 3, 2004)

I wonder if you could connect a low pressure 1 bar blow off valve to the plenum to mitigate the risk of damage to your plenum in the event of backfire into the induction system happens. Normally the blow off valve is used on boosted motors mounted prior to the throttle body.

Thread is filled with lots of good information.
Cheers
ny_fam


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## Brian.G (May 8, 2010)

ny_fam said:


> I wonder if you could connect a low pressure 1 bar blow off valve to the plenum to mitigate the risk of damage to your plenum in the event of backfire into the induction system happens. Normally the blow off valve is used on boosted motors mounted prior to the throttle body.
> 
> Thread is filled with lots of good information.
> Cheers
> ny_fam


 You could, but a burst panel is more common.

http://www.compperformancegroupstor...?Screen=PROD&Store_Code=FS&Product_Code=54002

link for demo only, theres tons, some very small and easy fit. You could also rob one off any plastic intake as they all(?) have them.

see my old post 29 here>

http://forums.vwvortex.com/showthre...ner-intake-Saw-one-but-no-idea-of-performance.


Brian,


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## ny_fam (Apr 3, 2004)

Seems some of the Porsche guys run a similar valve on the CIS system to protect the CIS meter from back fires.
http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_UPrc91_pg13.htm


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## [email protected] (Jan 13, 2005)

More Ford Cosworth eye candy! :thumbup:


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## Forty-six and 2 (Jan 21, 2007)

It's about that time for me to start on this project again. I have seen some pretty impressive flow charts on bottom center throttle body placements. Anyone have done their research and have any plenum design thoughts to add? 

I will be using an air/water ic setup, so piping turns will also be factored in when considering pressure drops and flow characteristics. Any info you can share about designing the best possible plenum/intake would be appreciated. 

I love this subject, so please share your thoughts.:beer:


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## zoidmk5 (Sep 17, 2006)

this thread reminds me of the first time i ever saw this monster 

http://www.precisionenginetech.com/products/2010/12/14/carbon-fiber-dual-ls7-intake/


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## Forty-six and 2 (Jan 21, 2007)

Anyone have any good info or experience with compression molds?



I am trying to get away from vacuum bagging. I am at 6500ft above sea level, which means I can only pull 10-11 pounds of vacuum on a good day... I am leaning towards a multi-piece compression mold. I would be able to compress the fabric nearly however much I design into the mold. I just don't know about some of certain specific details. 

Should I still be layering as if I will be pulling vacuum? If I wet lay it will I still need to be as concerned with my fabric/resin ratio? I seems with an extra bleeder layer, and pretty high compression rate, a good majority of the resin will be forced out. I'm not saying that I would just slop a ton of resin in it, but be a little more lenient with the ratio.

I am also looking into prepreg, but just looking out for all my options.


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## Brian.G (May 8, 2010)

Forty-six and 2 said:


> Anyone have any good info or experience with compression molds?
> 
> 
> 
> ...


Compression moulding is going to cost you, as high tolerance is needed - read cnc machined moulds. You can just do a female, and pour casting resin into that, but the casting resin will shrink, so you wont have even compression all over. 

On a side note, after trying loads of stuff, and seeing it done in Ferrari, Pagani, and numerous CF plants in China, and also speaking with the guys there, Id go right to prepreg. Until you try it, you will never realize how much of a compromised mess wet lay really is.


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## Forty-six and 2 (Jan 21, 2007)

I was a little off with my terminology. I believe I am meaning to say a cold press mold. My plan is to hammerform a female mold, then reinforce it to withstand a good amount of force. I am considering making the first inner bag to cover the fabric, then a second one to fill with sand. Then use a bottle jack to press the sealed sand bag into the mold. In theory, it should conform to the inner portions of the mold with pretty close to even pressure. I will leave it under pressure during the post cure process.

If I were to go with a wet layup, should I bag the carbon the same as I would when vacuum bagging it? Peel ply and bleeder cloth? Also, would you happen to know how to calculate the thickness of the fabric with resin would be? I will be using 5.7oz 3k twill, if I don't end up with prepreg. I know I can make a test piece, but just curious if there is a mathematical way.


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## RBPE (Sep 4, 2011)

0


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## leebro61 (Nov 7, 2001)

Is that Atari CFD?


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## Brian.G (May 8, 2010)

leebro61 said:


> Is that Atari CFD?


looks more like zx81


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## RBPE (Sep 4, 2011)

Lol, 2D tastic, it's the free FDS I taught myself on originally, we've used 3D ones too.


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## kamahao112 (Nov 17, 2007)

http://www.extrudabody.com/servlet/the-330/Carbon-Fiber-Plenum/Detail


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## Forty-six and 2 (Jan 21, 2007)

http://www.ozmoengineering.com/index.php?option=com_content&view=article&id=11&Itemid=9











Another premade one. Just isn't what I am looking for.


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## leebro61 (Nov 7, 2001)

RBPE said:


> Lol, 2D tastic, it's the free FDS I taught myself on originally, we've used 3D ones too.
> Still, only morons would think that a pretty 3D flow dynamics pic of a manifold would mean that a product had been thoroughly tested and so buy it, at least i'll be putting the hundreds of hours testing online and go into detail from the angle of bends to varying boost pressures :thumbup:


Absolutely nothing wrong with 2D flow solvers... they just require a bit of insight in setting up the geometry and boundary conditions such that representative flow physics are captured. I'm actually working on a 2D CFD code I started in grad school to do some merge collector optimization for a NA header (obviously the one below is a baseline run... notice the large separation in the diffusing section). 










I've also started some work on intercooler end tank design. Again, a baseline run shown below for a generic center inlet end tank.











Forty-six and 2 - I'd be happy to help you run some crude cases if you have some designs you'd like the shake down. Unfortunately right now I am somewhat limited in the complexity of the geometries that I can accommodate in my code but I'm sure we could at least get a rough idea directionally of better/worse, etc.


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## Forty-six and 2 (Jan 21, 2007)

That's would be awesome! I am going to make a foam plug of the hammer form I need. Basically it will only be used to take measurements and make quick changes before finalizing anything. Once I shape it, I can pm you the dimensions.:beer:


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## Forty-six and 2 (Jan 21, 2007)

I decided to make a foam version of the wooden hammerform I will end up making. Basically to make sure I have the dimensions correct, and that it will actual fit in the bay.

Started off with all my measurements...










Then cut a second one, glued it to the first, and started sanding it into shape.






































The wooden version will be 3-4" longer down the bottom perimeter, where the plenum bottom will attach. The extra length will be for mold reasons... There are some sanding imperfections in the top radius of the foam plenum that will be corrected in the wooden shape. 

Once I have the hammerform made, I will use 18 gauge sheet metal to form a two piece mold. The formed sheet will be far from strong enough without bracing. I haven decided exactly what method I well use to do that, but it will be pretty simple however it's done. I will have to flange both halfs, in order to bolt the two together. After flanging and bracing the halfs, I will build a cage type structure around each side with 1" square tubing. This will further strengthen everything, plus make it easy to position during use. I will also have to make a simple upper cage to allow a place for the jack to press the "sand bag" into the mold. I figure a scissor jack will be the best option to maintain constant pressure during the post cure cycles.

The plenum bottom, velocity stacks, and flange will all be aluminum. I am waiting on the material now, and will get it all fitted and welded soon.


I am still wondering what 12 layers of 5.7oz tell fabric with resin thickness will amount to. I have read the dry fabric is .009, which will amount to .108 at 12 layers. I'm not sure how to factor in resin and compression without laying up a test panel.


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## Forty-six and 2 (Jan 21, 2007)

Before I continue with this design, what are some of your thoughts about the TTRS manifold? It's has a 90° inlet to the runners. I have always been interested in the idea...


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## Scullies (Apr 17, 2012)

That is awesome work. 

Whats your reason for making a metal mold, wouldn't a fiberglass mold be easier to get the perfect shape of your plug.
How do you intend to lay up the CF ? Are you going to lay it in each half then press the mold together, leaving a join line between the 2 halves.
How would the TB be attached to the inlet? Wont you need a flange of some sort to bolt the TB up so you get a good seal.

Sorry for the 20 questions, just really interested in this and I WANT ONE


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## Forty-six and 2 (Jan 21, 2007)

I have a hemi flange welded to a 3" piece of schedule 10 pipe. I need to transition the inside edge of the pipe once I figure out exactly how it will fit. I am debating whether to lay this up in the mold, of epoxy it in afterwards. I am leaning towards afterward for a couple reasons.










Mold quality is the key to a quality part. They have to withstand a lot of heat and pressure for a part like this. I am going to use a high temp resin that has a final post cure cycle of up to 350° for an hour. A simple mold will fail before reaching those temps. The high temp cure is to get the resin a higher working temperature. Most epoxy resins can withstand up to 190°, but are very weak when put under any pressure. High temp resins, when post cured, can withstand 450° while maintaining strength under pressure. Another reason for the strong mold, is to allow me to use extreme pressure while letting it cure. Simply vacuum bagging a part will only produce 14.7psi at sea level, and 11 or so at my altitude. That is hardly enough to make a strong enough part. I would like to be able to press it with upward of 100lbs. Carbon race car parts are autoclaved at 10+ atmospheres, while being heat cured. 

I have a set of molds that I used the first time attempted this project that worked well for a vacuum bag, heat lamp cure, but won't work out for me time... I used mdf and body filler to make them. They weren't precise enough, and were made for a different throttle body. 

This time I will bolt the two molds together and lay it up as a one piece plenum. I figure it will make a stronger part this way. It will probably be a little harder to lay the fabric in though. I am still trying to sort out that plan. If I end up going with a plenum similar to the TTRS one I posted, it will make everything a whole lot easier...


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## kamahao112 (Nov 17, 2007)

http://www.ikengineering.co.uk/manifolds and plenums.html


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## Forty-six and 2 (Jan 21, 2007)

I shaped another block of foam...





































I still need to make a few changes to it before I start on the wooden version. I am pretty happy with the overall design. 

The throttle body flange sure does make for some big proportions!  

Give me your opinions please.:beer:


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## mldouthi (Jun 26, 2010)

Forty-six and 2 said:


>


Looks like a NUB weld 



Its good to see work being done on this. opcorn:


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## Forty-six and 2 (Jan 21, 2007)

mldouthi said:


> Looks like a NUB weld
> 
> 
> 
> Its good to see work being done on this. opcorn:



It sure does. He will be doing welding for this project. A big thanks to him for the help with the welds and flanges.:beer:

I do need to pick up a tig though. Maybe after selling a couple of these things...


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## mldouthi (Jun 26, 2010)

Forty-six and 2 said:


> It sure does. He will be doing welding for this project. A big thanks to him for the help with the welds and flanges.:beer:
> 
> I do need to pick up a tig though. Maybe after selling a couple of these things...



He does some nice looking stuff. I saw this on fb a week or so ago. :thumbup:

I will second that on getting a tig setup.


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## leebro61 (Nov 7, 2001)

mldouthi said:


> I will second that on getting a tig setup.


Best purchase I've ever made :thumbup:


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## Forty-six and 2 (Jan 21, 2007)

Transferring measurements to a block of oak for the hammerform...










Basically making everything precise and making slight changes. I will try to get it cut this weekend.


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## sdezego (Apr 23, 2004)

I like where you are heading with that Matty  opcorn:


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## Forty-six and 2 (Jan 21, 2007)

Me too! This plan for the mold construction is much better than the last, and should make them very precise. I am just trying to figure out how to connect the two half back together, since making it a one piece part, may be too difficult. The best I have come up with is an external flange... It would be well placed, to avoid running the aesthetics of the part, but I'm not 100% satisfied with that idea yet. I would think that it would need near 1/2" to bond the parts well, and possibly have bolts as well.

If anyone has experience with bonding two half together, or a better idea, please share your thoughts!:beer:


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## zoidmk5 (Sep 17, 2006)

possibly create bosses into your mold, somewhat like the 1.8T manifold from Integrated Engineering. then when you go to put them together, insert a threaded steel standoff on one side to catch the bolt as it goes through the other. you will want your mating surface to be decently thich, to carry the load of the bolt, and wide, so you have plenty of mating surface area, and for your holes not be too wide spread since the CF will tend to warp or pull away, causing a non-true seal all the way around, in which you will need a gasket of some sort as well


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## Forty-six and 2 (Jan 21, 2007)

Still needs a little refining, but just about ready to form some sheet metal...


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## Scullies (Apr 17, 2012)

What about making the 2 halves, place them together then wrap more CF around the whole plenum and vacuum bag it. Not sure how many layers would be needed if even possible.


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## Forty-six and 2 (Jan 21, 2007)

That was my plan for the first time I made the attempt. I didn't really like the thought of it after having the two half in hand. Like I said, at my altitude vacuum isn't very impressive. Relying on a bag setup is fine for non-structural parts, but I really don't trust it for this one. 

I have settled on using prepreg with vacuum for air removal and initial compression. Once it's all in place, will use a inner molded shaped sand bag and scissor jack for extra compression. I will be able to apply as much pressure as my mold bracing can withstand. My theory is that the sand will apply fairly even constant pressure during the post cures. Sand is really the only thing I can thing of that will withstand the high temps during the cures. 

I really would like to figure out how to make it one piece. The problem that I am coming up with is laying it all up tightly around the throttle body tube... The mold would have to be at least three pieces, and then I still would need to solve keeping the fabric in place on the negative angles before I get the vacuum bag setup started. It's possible, but has me stumped on the best method for making it happen. Then there is the question of do I place the throttle body in before curing or epoxy it in afterwards.

A epoxied and bolted flange would be a fairly simple solution, but you are left with nearly a 1/2 flange around the part. It's not the end of the world, and can be well placed so that it's not an eyesore. It would make layup extremely simple too. 

I am working on producing modified steering wheels right now. So I have a good but of my money tied up in that for the next coupe weeks. I will get back to this as soon as I can. I am dying to start on the molds though!


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## mldouthi (Jun 26, 2010)

I havent read this thread in its entirety but if you are looking to make this in one piece, why not make 2 fiberglass molds (halves) of your wood block. Then lay the carbon in each half, bolt it together, put a badder in the middle, and then hook a compressor up to it. I have a buddy that worked at a carbon shop and that is how they made most of there hollow parts. The fiberglass molds were like .25in-.5in thick with a built in flange.

These was made in the described way.


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## Forty-six and 2 (Jan 21, 2007)

I am going to continue with the metal mold, but I am interested more in that technique.

If you were to layup both halves separately, what connects them within the mold? Is there some kind of overlap? Also what is the inner bladder made of?


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## mldouthi (Jun 26, 2010)

Forty-six and 2 said:


> I am going to continue with the metal mold, but I am interested more in that technique.
> 
> If you were to layup both halves separately, what connects them within the mold? Is there some kind of overlap? Also what is the inner bladder made of?


There is an overlap within the part. I will have to ask what they used for a bladder, I know its some type of plastic. 

Here is a video I found that shows the process pretty nicely. 
http://www.youtube.com/watch?v=zeLC-miXSwo

Also here is a video (guy is pretty ridiculous haha) of how to make 2 part fiberglass molds.
http://www.youtube.com/watch?v=--tSlGyASPU


Im looking forward to seeing your progress.opcorn:


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## Forty-six and 2 (Jan 21, 2007)

Thank you for the suggestions. :beer: 

I think I will go the fiberglass route. For some reason I didn't even consider a high temp tooling resin. EZ-lam makes one specifically for making tooling for the resin that I will be using. I will just start on getting a perfect finish on my oak, then make it happen. 

I read that bladders are made from uncured silicone sheets. You use your mold as a form, glue it together with silicone, then bake it to cure it. I suppose you would set you air line connector up into it at that point too. If you could ask your friend about his method I would appreciate it.

I have been searching for a high temp prepreg supplier, that will sell in small quantities, and can find one. I will end up using the proper resin to make my own "prepreg". It basically involves taking your exact ratios, then using a spreader to, as evenly as possible, spead the resin through the fabric. Once you wetout the fabric properly on a piece of plastic, you lay another plastic sheet over it, then freeze it. Once frozen you will have your home made "prepreg" with your choice resin, and ratio. I can either roll the fabric up and use my freezer in my kitchen, or use a "bed" of dry ice which will make it ready to use within a very short amount of time.

I am pretty excited about getting back to this project in a few weeks. I really wish I could order everything right now, but I have to be patient. I am also in the middle of building molds for a flat bottom steering wheel for a MkI TT and B5 A4/S4. I am just waiting on the supplies... The manifold project is majorly tempting at the moment though.


----------



## mldouthi (Jun 26, 2010)

Ive already sent my friend the question about the bladder. Ill also ask if he knows where to get small quantities of prepreg.


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## mldouthi (Jun 26, 2010)

He said they just used plastic bags, and had a machined connector to attach a quick disconnect air hose. I also shared this link with him and he said a custom shaped bag would work best in something like that, to give even pressure to the carbon.


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## carsluTT (Dec 31, 2004)

hope this pans out, its a cool project


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## Brian.G (May 8, 2010)

mldouthi said:


> I havent read this thread in its entirety but if you are looking to make this in one piece, why not make 2 fiberglass molds (halves) of your wood block. Then lay the carbon in each half, bolt it together, put a badder in the middle, and then hook a compressor up to it. I have a buddy that worked at a carbon shop and that is how they made most of there hollow parts. The fiberglass molds were like .25in-.5in thick with a built in flange.
> 
> These was made in the described way.


 Indeed thats the way. To whoever is trying this, its no harm to cut a few runners at the parting line to allow excess resin to be pulled away, either by just the force of the internal bag, or incl vacuum force if you pull some vacuum on the parting line runner drain system.


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## Forty-six and 2 (Jan 21, 2007)

Brian.G said:


> Indeed thats the way. To whoever is trying this, its no harm to cut a few runners at the parting line to allow excess resin to be pulled away, either by just the force of the internal bag, or incl vacuum force if you pull some vacuum on the parting line runner drain system.



Would this even be necessary when using prepreg? Assuming you have a 50/50 ratio, you wouldn't want to get rid of much resin. At what point is a lowered resin content risking delamination? 

Would stretching bag material and bag tape be able to produce a decent bladder? I know it would have to be well cut to avoid fabric bunching once it's inflated. I am looking into latex, but just looking at other options aswell. 



I read an article on auto clave pressures, compared to vacuum bagging w/a bladder. The results were pretty interesting. The exact same part was made, with same prepreg. The auto claved part was cured under 5 atmospheres of pressure, 73.5 psi. The vacuumed bagged part at 14.7 psi.

The auto claved part was thinner due to the extra compression, and only 1-3% stronger. The vacuum bagged part had a slightly higher resin content, but was closer to the 50/50 ratio. The auto claved part may have been a few percentages stronger, but was more prone to delamination and failure at the parts corners and edges. This is due to the higher pressure on all of the corners/edges actually pushing the resin and fabric away from them, causing it to be thinner and have even lower resin content.

These tests were done by an aerospace company looking to prove that an auto clave isn't a necessity when it comes to producing a high quality part. They concluded that both methods will produce a high quality part, but vacuum bagging with a bladder at a single atmosphere can produce a part with only a couple percentages away in strength, while eliminating some of the reasons for failure with an auto claved part.


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## mldouthi (Jun 26, 2010)

Forty-six and 2 said:


> Would this even be necessary when using prepreg? Assuming you have a 50/50 ratio, you wouldn't want to get rid of much resin. At what point is a lowered resin content risking delamination?
> 
> Would stretching bag material and bag tape be able to produce a decent bladder? I know it would have to be well cut to avoid fabric bunching once it's inflated. I am looking into latex, but just looking at other options aswell.
> 
> ...




That shop mostly uses prepreg, even when using a bladder mold. But they use an autoclave when doing it.


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## Brian.G (May 8, 2010)

Forty-six and 2 said:


> Would this even be necessary when using prepreg? Assuming you have a 50/50 ratio, you wouldn't want to get rid of much resin. At what point is a lowered resin content risking delamination?
> 
> Would stretching bag material and bag tape be able to produce a decent bladder? I know it would have to be well cut to avoid fabric bunching once it's inflated. I am looking into latex, but just looking at other options aswell.
> 
> ...


every plant and factory I have been in that use this method, use the gates at parting line. On every opened tool I saw, the runner has some resin in it, so it appears some gets exited out with the pressures. Keep in mind that if your tools fit real well together, the air outside the bag will need to go someplace as bag inflates too. I agree, that a clave isnt necessary, and many parts now are being ran without it. Plants where I have been and witnessed CF work include Pagani, Ferrari, and many high quality CF fabricators in China, making race bikes, spoilers for F1, Aero, and quality House wares. May of the China plants used a heated tool, and just the Vac bag. The tool was heated by pumping steam through it for 20min once tool was closed. Tool was heated for five minutes, bag inflated and pressure held, and then left like that for another 15min. I think temps were around 150deg c, with not much ramp down at all, just disconnected, left to cool a bit and cracked open. 

For the bags, they made many themselves, if you imagine a ziplock bag - thats what the Vac bag material was like. Not elastic as such, just big enough. They bought it in different 'tubes' on the roll, and used to ultrasonically weld it each end. The bag was then given the air fitting by heat stamping a plastic fitting onto bag wall. Come to think of it, I dont know why Ive been calling it a vac bag, as it gets inflated - but you know what I mean.
Be warned that even small bag pressure will put massive separation forces on your tool so be careful. I had a small enough prototype tool made here in alloy before christmas, and for 15psi bag pressure, my tool separation forces were touching 3.5tons!

You should be aware, that towel rail elements make great tool heaters, or similar elements that are flexible(amazingly!) work great too, these can be got on ebay for about 15euro for say a 20'' long one. 
Im not sure how good these would work bonded into a glass fiber tool, but for alloy, I just mill a groove in the rears with an 8mm roundnose mill, and seat the element in there with some thermal paste. Small alloy sprigs are driven in after to hold element in place. 
Theres loads more, Ill post as I think of it, but its handy enough. Due to the amount of work in building a glass fiber tool, and, the possibility of any reinforcements you glass in there having a different expansion rate to the glass(warped tool) I go right to alloy tools anymore if its important. 

Brian,


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## Brian.G (May 8, 2010)

Also, remember when calculating clamp forces to keep both halves together, you only use the cross-sectional area across the parting line. This can be also called projected area, or part silhouette area if you want to do some more lookup reading.

So, lets say you wanted to make a CF shoebox - fully sealed.

Box size, 15'' x 10'' x 6'' 

The cross-sectional area at parting line will be 15 x 10 = 150sq Inches, multiply that by your psi, say 20psi, and you get 3000 pounds over the area of one tool surface!! Thats 1360kgs. That will cause a poor tool, to either creak, and make you nervous, or crack, or burst in halves. 

Brian,


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## Forty-six and 2 (Jan 21, 2007)

The towel real element it's a great idea! I may not use it on this round, but will definitely keep that tip in mind for the future. :beer:

I have a junk refrigerator that I will set up as a "hot box". This will be only used for the initial 100-150° cure and other general curing. I also have a spare oven, that I will use for the high temp cures, from 200-400° post cures. 

Thanks for explaining the tool pressures. I knew I would need to make sure it was strong, but didn't think of actually figuring the true forces involved. I am waiting on my tooling gelcoat and resin. The plan is to glass in 1" square tubing for bracing, as well as some sheet metal. I figure if I can come up with good bracing structure, bolted flange, and an exterior clamping system, it will have a good chance of surviving. It would be nice to have an aluminum setup, but the cost out weights the actually need for it. I plan to make a handful, and sell a few, so if it can last for a limited run I'd be pretty happy.

What are your thought on how many layers I should use. I have 5.7oz. 3k twill. I need it to withstand up to 40psi. The original plan was to go with 10-12 layers. It seems to make the most since to do it all at once, due to cure cycles and lamination reason. My real concern with that is exothermic runaway. The part will be pulled from the tool after the initial cure. So the tool itself isn't a worry, but my oven, part, and garage/house is! Should I even be concerned when the highest cure temp is 350°? Will the highest exothermic temps be during the first cure cycle?


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## TheBurninator (Jan 7, 2009)

Forty-six and 2 said:


> Before I continue with this design, what are some of your thoughts about the TTRS manifold? It's has a 90° inlet to the runners. I have always been interested in the idea...


The 90* transition on this is a prior to the throttle body.

I can post an ETKA diagram of it if needed.


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## Forty-six and 2 (Jan 21, 2007)

Yeah. I would love to see it. I just used it as a design idea.


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## l88m22vette (Mar 2, 2006)

That design is essentially a Lehman-style plenum, it is designed to distribute flow more evenly than a typical side-feed plenum. Still, a proper upgraded manifold would give the best power, a good discussion (argument) of Lehman vs. aftermarket side-feed is here: http://forums.vwvortex.com/showthread.php?4620769-WRC-engine-details

In the end, a Lehman is more restrictive, but conversely can provide more equal flow and be tuned for a "sweet spot"


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## Scullies (Apr 17, 2012)

Can I buy one yet


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## d-bot (Sep 6, 2004)

This thread makes me want to make composites!


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## Truckinduc (Apr 24, 2011)

i want to see updates


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## Brian.G (May 8, 2010)

Not sure If I linked this already but the guys that own a supplies place in the Uk started a forum a while back, 

http://www.talkcomposites.com/Default.aspx

You will also find info by searching FSAE Student papers/stuff, 

https://www.google.com/search?q=FSA...lla:en-US:official&safe=off&tbm=isch&imgdii=_

Brian,


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## Forty-six and 2 (Jan 21, 2007)

I have started a 2.5l engine build. The first manifold will be aluminum. Once the motor is in the car and running properly, I may get back to this.


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## KlokWerk (Mar 17, 2006)

I think you're on the right track with the two peice mold and bladder.
That's the same direction I went with mine.

My problem is that I'm working on too many projects at the same time to get this one done.
But here it is. It's based on some designs I lifted from DTM E30 M3's from back in the day.










The one I'm building will be for a 16V head. I'm also working on one for a VR6. That one will be a little harder.

I'd love to compare notes.


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## Truckinduc (Apr 24, 2011)

Found some nice NA plenums


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## Truckinduc (Apr 24, 2011)

I started building my 1.8t plenum.. Im just about finished with the aluminum base plate with the runners. I am seriously considering building the rest from carbon and bolting it together. I was planning on building it from aluminum but why not carbon. 

Design is my own with a 90 degree bottom entrance. From the throttle body plenum 1 will taper to a slot the width of the plenum 2, with the cross sectional area slightly increasing proportionately. 

Max boost should be <30lb so im not incorporating a pop off valve. 

First one will more than likely be fiberglass. 

I planned on tuning runner length with a Phenolic spacer of varying thickness between the head and manifold.


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## Truckinduc (Apr 24, 2011)




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## KlokWerk (Mar 17, 2006)

That looks great!
And bolting on a carbon or fiberglass box to complet the plenum would be pretty straight forward.

Build your plug, provide enough thickness to allow for the bolts to compress the form without cracking. Make your mold and then start pressing parts! You should be good to go.


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## Truckinduc (Apr 24, 2011)

Well I finally welded the two pieces together


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## MaxxedOutMotors (Nov 5, 2004)

Looking good and having spent many hours vacuum bagging, I am really enjoying reading this thread!!!1:thumbup:Keep up the good work and I look forward to updates..


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