# VrT Intake Manifold



## MKippen (Nov 6, 2000)

Well, after putting some thought into it, and talking with my friend that has been helping me put together my motor setup, i think that this is going to need a little more thought than I originally figured.
I am working on putting together a new Vr6 Short runner Intake manifold that uses the OEM intake runners... something like this








My friend has told me that i need to be VERY careful designing this, in the fact that we dont want 1 cylinder getting starved for air, which the furthest away from the TB might have a problem with. This is why i am asking... what should i look out for? should this be tapered down? really, how should i go about designing this?
reason i am building this one, is because i need the space in front of the manifold for the IC, and I cannot use a traditional shorty style.
please give any tips or suggestions you might have.


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## MKippen (Nov 6, 2000)

*Re: VrT Intake Manifold (theflygtiguy)*

nobody has designed their own intake manifold??


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## GTijoejoe (Oct 6, 2001)

*Re: VrT Intake Manifold (theflygtiguy)*


_Quote, originally posted by *theflygtiguy* »_nobody has designed their own intake manifold?? 

I believe what is important is the Volume of the plenum to the displacment of the motor. There is a specific percentage of what the relation should be, but I've seen the tapper down style which you were refering too.


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## bdfeenie (Jan 26, 2004)

Bill Schimmel desgined his own recently. Might save you some time.
http://www.spturbo.com


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## BoostFactory (May 27, 2005)

*Re: (bdfeenie)*

mine is about 2x the size of my displacement, it was done by racecraft a couple of years ago http://****************.com/smile/emthup.gif 
performs great.

hth
Paul


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## Scooter98144 (Jul 15, 2002)

*Re: (BoostFactory)*

Maybe find one of these for a song?


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## [email protected] (Oct 19, 2005)

*Re: VrT Intake Manifold (theflygtiguy)*

Heres a picture of the intake of my friends vr6 Twinturbo!
http://redliners.se/vr6/projek...4.JPG


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## foffa2002 (Jan 14, 2003)

*Re: VrT Intake Manifold (theflygtiguy)*

Thats not a short runner .
Thats OEM lenght
You should only have 2-3inch runners for the VRT-shortrunner.
Cone shaped for good flow/even distubution of air 












_Modified by foffa2002 at 11:14 AM 11-2-2005_


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## MKippen (Nov 6, 2000)

*Re: VrT Intake Manifold (foffa2002)*


_Quote, originally posted by *foffa2002* »_Thats not a short runner .
Thats OEM lenght
You should only have 2-3inch runners for the VRT-shortrunner.
Cone shaped for good flow/even distubution of air 


Well, would it still be WORTH it to even do a short runner like this?? against stock? 
I have moved my radiator back against the intake manifold, so i could fit my FMIC in front of the radiator without hacking my frotn bumper, which is why i dont have room.... and why i wanted to do it this way.
do you think i should even bother?


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## AlwaysInBoost (Sep 4, 2001)

*Re: VrT Intake Manifold ([email protected])*


_Quote, originally posted by *[email protected]* »_Heres a picture of the intake of my friends vr6 Twinturbo!
http://redliners.se/vr6/projek...4.JPG


VERY nicely done! http://****************.com/smile/emthup.gif


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## BanBanBan (Nov 1, 2005)

*Re: VrT Intake Manifold (AlwaysInBoost)*

C2 makes one http://****************.com/smile/emthup.gif


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## foffa2002 (Jan 14, 2003)

*Re: VrT Intake Manifold (theflygtiguy)*

To get the power out of it you must go with the ultra short ones aka lower mani lenght or shorter .
i made some sick gains with my intake .
[email protected] were the old intake just flaten out 

What about the C2 one ??
Will it still hit your radiator ??


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## MKippen (Nov 6, 2000)

*Re: VrT Intake Manifold (foffa2002)*


_Quote, originally posted by *foffa2002* »_To get the power out of it you must go with the ultra short ones aka lower mani lenght or shorter .
i made some sick gains with my intake .
[email protected] were the old intake just flaten out 

What about the C2 one ??
Will it still hit your radiator ??

i think that the C2 one would still had the radiator (plus i have a shorty fan behind that)...
regardless of its short-runner, it would still be saving me about 1 1/2 feet of piping for the intercooler, so i htink it might still be worth it either way... but if there is some way i could design this, so it does flow better, thats what i am curious about.
some good ideas, thanks everyone.


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## ForsFedRado (Sep 28, 2005)

to start the intake runners need to be the same lenth. On the factory manifold the upper has three runners 420cc longer to make up the difference in the runner length in the cylinder head. That on a vr intake would be the most important. then intake volume


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## foffa2002 (Jan 14, 2003)

*Re: (ForsFedRado)*

Mk4 runners = same lenght .
They adjust the flow with the cyl head diffrent port size .


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## ForsFedRado (Sep 28, 2005)

*Re: (foffa2002)*

YES THEY DO, BUT THAT IS IN THE INTAKE MANIFOLD NOT THE HEAD. wHEN BUILDING A SHORTN RUNNER INTAKE YOU ILIMINATE THOSE PIECES


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## RadoV6 (Oct 9, 2004)

*Re: (ForsFedRado)*

I wouldn't want to sound gay, but Schimmel manifold just look like a 1.8T manifold with a VR6 lower manifold mix up. In my mind it's not worth 1 gran.


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## EternalXresT (Jan 5, 2005)

what do you guys mean when u compare the size of the plenum to displacement??? 
what measurements do u take to know how big it is compared to displacement?


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## EternalXresT (Jan 5, 2005)

?????


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## leebro61 (Nov 7, 2001)

*Re: (EternalXresT)*

How do you find the volume of a cube (l^3)? The volume of a circle (4/3Pi*r^3? There are formulas for all of this. How about the volume of a cylinder (Pi*r^2 * l). It's really only high school math








For the common manifold (like schimmel used to make) if you have a cylindrical plenum, the volume is Pi*r^2 (area of a circle) times the length of the cylinder. The more elaborate your shape is, the tougher to estimate its volume.
If it really matters to you, seal off all the holes in the manifold and fill it with something. Then just measure the volume that it will hold that way.
Is that what you were asking?


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## EternalXresT (Jan 5, 2005)

well yeah, so the volume of the tube/cylinder should be what compared to the displacement?


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## leebro61 (Nov 7, 2001)

*Re: (EternalXresT)*

Depends who you ask...
Optimally: XXX% of your engines displacement
Reality: As big as you can possibly fit


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## EternalXresT (Jan 5, 2005)

ok thats what i wanted to know.....so measuring it doesnt need to be done. just make it big lol


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## golfturbo95 (Jul 11, 2005)

*Re: (EternalXresT)*

Im in the proccess of desighing one for my 8v to and I got some questions also. 
so all the runners need to be the same length? Or as the cylinders get further away from the the throttle body the length of the runners should get shorter? is that right?
I would think that leaving the runners all the same size wouldnt matter because its forced induction once that things is hitting boost its a preasurized system. But i guess you wnat all the cylinders getting the same preasure at all times. hell im lost.


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## stealthmk1 (Aug 17, 2001)

*Re: (golfturbo95)*

I'm not an engineer but on a FI motor does it really matter since the intake charge is pressurized? I could see on a NA motor it being an issue but I ahve heard that on a turbo car as much air as you can get in and out of the combustion chamber is best.


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