# food for thought...dyno plots of stock vs bmw VAM



## DjSuperChink (Sep 29, 2003)

Ok I have some pretty decent information for you guys.
A couple of things to keep in mind. I am running DigiII...BUT its a 2.0 16v Digi.
There are obvious things that are currently wrong with my setup...so If you're a CIS guy just wanting to rip on me...save it for yourself...I'm digi all the way, I will never go to CIS...I consider my injection setup less archaic than mechanical CIS...There is no need to flaunt your CIS here, if you have nothing constructive to add...LEAVE...
*Oh, I was thinking about this after I typed all this out...please don't think that I came in here to brag about 16v vs 8vs...I just wanted to show you guys that digiII (which originated from 8vs anyways) has potential when paired with some home-brewed ingenuity...seems so many vw die hards are so quick to knock digi down...*
Ok, where to begin...I have more potential...but I have things I need to fix.
I am running digiII with an AMS chipped ecu. I have 24# corrado injectors. I have a generic adjustable FPR...my 16v head does have a slightly larger cam some port work and I have headers...so the last 3 are also helping in the increase in power for the BMW VAM...
The first plot is with my stock VAM.
The second plot was with the BMW VAM.
Both were run on the same day, same dyno, nothing else was changed unless noted below. Both plots have 2 pulls each. Blue line is first pull and Red line is second pull
*Stock Vam*








*BMW VAM*








on the stock plot. I had my FPR set to 35 psi of fuel pressure. I assumed that since my AMS ecu was richining the mixture as is, I didn't need to have the fuel pressure so high, so I backed it down from where others have said was a good point (note: research pointed to if you're running a stock ecu, 40-45 psi is a good place to be)
The BMW plot, I just put the VAM on with out correction to the fuel pressure...Read BLUE LINE.
I then bump the fuel pressure up by 5 psi. I am now running at 40 psi of fuel pressure. The correction brought my line a little closer the ideal...but I still have some issues to sort out (as evident by the mountain that is formed in the middle...but tahts another day, and another post)...the rise in fuel pressure netted me about 2 whp...but the BMW netted me overall a 11.68 whp...not too bad for being such a pain in the ass fuel system and apparently such a waste of time as compared to CIS...
well, thats my small contribution, hope this helps others and as always if you have anything constructive, please add as this may turn out to be a usefull thread...


_Modified by DjSuperChink at 11:12 PM 4-5-2005_


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

Finally some evidence about this mod! 
Good job man! I am thinking of doing this mod too. 
You have an adjustable rising rate FPR? If yes which one and can we see a photo of the install? I recently posted a question here about a SARD I found on ebay for a good price.
I have the AMS chip as well and I can feel the car needing more air after a free flow exhaust install. 
My only concern is that I will have to use an induction kit and I don't want it (hot air, noise etc). I am on K&N panel filter at the moment. 
Thanks again for the post!


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Black_cabbie)*

the adj fpr I got was just a generic one off of ebay
looks like this guy on ebay

It wasn't listed as a rising rate, just adjustable...I bought it from a guy who bought it for his toyota supra but decided not to go that route for cheap.
I'll take a picture of mine in a few days...
I want to invest in a aeromotive one...but they cost a lot...but a good adjustable fuel pressure regulator is essential for the BMW VAM mod to work correctly, even if you're running a chipped ecu already.
I'll get pics of mine induction setup too...but there are always around the hot air issue when using a cone filter. You can build a pretty good home made heat shield to go along the frame rail from supplies from home depot (oops, didn't notice you're not in the states...a good hardware store would suffice), or run another tube down where the gas purge canister would normally be.
Actually the fpr is identical to this one on ebay...



_Modified by DjSuperChink at 9:32 AM 4-6-2005_


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

Well, after some investigation in german ebay, I found that most of the 3L AMFs are the big ones. Not only BMW. I found an Opel Omega 24V which is the same. Some come with their airbox some don't. 
I don't know if you can modify your old box to fit but wth I am going to try. 
I was going to buy this one but I am still reading to see if its good and what is the range of adjustment as the seller has absolutely no idea what I am talking about. 
http://cgi.ebay.com/ebaymotors...=WDVW
What I don't understand is how is the existing AFM is going to measure something when by the time I hit the pedal, I hear the flap inside hitting the stopper.


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Black_cabbie)*

when you mash the gas, the flap goes full open, the throttle body butterflies hit the WOT switch...at which point the ecu isn't really reading the VAM any longer...it is just dumping a bunch of pre-determined amount of fuel based on the calculated size of the stock VAM...thats why most poeple will tell you when you're in WOT mode, the computer isn't really realying on most of its sensors anymore to make adjustments...
because fo this, thats why it is soo important that you have an adj fpr to compensate for the larger VAM bore...basically at part throttle, using a larger VAM, the computer can still make some adjustments based on flap position, but once you're in WOT mode, the computer will just dump fuel in...but dump in based the stock VAM size...the adj fpr will let you maunally change the amount of fuel being dumped in...
at least thats how I figured it would be based on hearing others talk.


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

OH, either get a fuel pressure guage or get an adj fpr with a guage in the kit...since you won't have a clue as to where you are in your adjusting and tuning...very important.


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

I already have a fuel pressure gauge which reads 3 bar at idle and 3.5 at vacuum.







I thought it was supposed to be 2.5 at idle and 3 at vacuum. 
This looks like the same you got....
http://cgi.ebay.de/ws/eBayISAP...&rd=1
What do you think? 
Btw, I really need to see some photos of your engine bay http://****************.com/smile/emthup.gif


----------



## Digiracer (May 5, 2002)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

Nice work DjSuperChink, it's about F*(&ing time someone got in the game here... Seeing posts like these inspire me to get mine running again. thank you


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Digiracer)*

it was your how to on making the BMW VAM work, especially the 8-clicks un-tension, that helped me the most...even with my 2.0 16v, I had to do the 8 clicks...at first I went to 5 clicks becuase I thought since 16v breath a little better and being a 2.0 over a 1.8, I might not needed to unlcik as many...but it turns out 8 was the sweet spot.
didn't you have a dyno plot of when you ran a BMW VAM herte some where...?


----------



## username (Mar 27, 2001)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

awesome awesome awesome
i have had a bmw VAM sitting in my closet since last august.....your graphs have inspired me to get off my butt and put that thing in, SOON
i've already got a cABA bottom end, cam, ams chip, head work, exhaust, blah, blah, blah...i think its time i did this http://****************.com/smile/emthup.gif


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (username)*

thats where your gains will be from...all of the other mods you have...larger block, bigger cams, headers...letting more air in is the VAMs job, but using it and getting back out is also very important to making the sort of gains I saw. http://****************.com/smile/emthup.gif


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

Quick Q. Stock injectors with 3.5 or 4 bar fuel pressure or larger injectors with lower fuel pressure (something like 3 or less)? What is the effect in both cases?


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Black_cabbie)*

stock digiII injectors are blue top and 22# i think, corrados are 24#...There isn't a huge amount of difference there...I'm finally running at 50 psi of pressure now and it feels right although on the day I dynoed...I only went up to 40 psi which is equivalent to about 2.7 bar for that pull with the red line on the above plot.
My best advice would be blue top should be suffiecient, but an adjustable fpr is the best to have...this will give you control so you can tune it...if you can't score an adjustable fpr, then at least get the 3.5 bar unit since 50 psi is a little less than 3.5 bars and if you're running a stock ecu, you'll need your fueling bumped to about that point to compensate.


_Modified by DjSuperChink at 2:13 AM 4-7-2005_


----------



## username (Mar 27, 2001)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

are you running a air/fuel meter on your setup?


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (username)*

yeah...but I'm running a batan one...and a regular a/f meter is nto very acurate at all...


----------



## username (Mar 27, 2001)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

how are you tuning then? trial and error? (hopefully not BIG errors if you know what i mean







)


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (username)*

I have made only one change since the 2nd pull on the dyno.
On the dyno, I made that one change (upped the fuel fressure from 35 psi to 40 psi) and I got the RED LINE. Based on what I changed and the results I got on the graph, I went home and upped the psi by about 7 this time...now I'm running about 47 psi. Since the dyno day was only for 2 pulls, I didn't get a chance to see what going to 47 psi would result in...but I can guestimate from the previous change on the plot...
the a/f meter I have doesn't let me tune for sh&t...starting at 40 psi, it just lights rich (green LEDs) so you really can't tell...There's no replacement for a wide-band or a a/f curve from a dyno run...
even if you can't tune your car on the dyno...all you need is a couple of runs with different settings and you can guestimate pretty close with the changes in the graph would be to what you change.


----------



## Batan (Dec 15, 2000)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*


_Quote, originally posted by *DjSuperChink* »_I have made only one change since the 2nd pull on the dyno.
On the dyno, I made that one change (upped the fuel fressure from 35 psi to 40 psi) and I got the RED LINE. Based on what I changed and the results I got on the graph, I went home and upped the psi by about 7 this time...now I'm running about 47 psi. Since the dyno day was only for 2 pulls, I didn't get a chance to see what going to 47 psi would result in...but I can guestimate from the previous change on the plot...
the a/f meter I have doesn't let me tune for sh&t...starting at 40 psi, it just lights rich (green LEDs) so you really can't tell...There's no replacement for a wide-band or a a/f curve from a dyno run...
even if you can't tune your car on the dyno...all you need is a couple of runs with different settings and you can guestimate pretty close with the changes in the graph would be to what you change.

Yes, I would say that is way out of the narrowband sensor scope.
Just for the hell of it, what kind of mileage do you get with your setup?


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Batan)*

I have no idea what kind of milage...I'll measure on my next fill up...it runs and thats all that matters for now


----------



## rychas1 (Mar 2, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

well i'll be van-dammed! ive been asking this in the 16v forum...and the 8v forum answers it! eureka! for for a 1.8, would u say fewer than 8 clicks on the bmw maf? also..im thinkin 3.5 fpr on stock in jectors would be pretty good too? i thought that the only way that bmw maf would work is if u ran 50mm runners. guess not.







this is so neat. props to u for bringing to life what i have been saying all along.....digid rule


----------



## autobahnjs (Sep 14, 2002)

*Re: food for thought...dyno plots of stock vs bmw VAM (rychas1)*

i am running stock injectors,tt 286 cam, ported tb,advanced timing,g60head,4-2mani,chip,5"cone,bmw van at 8 clicks,4.1bar fpr....pulls like crazy ..i tried 3.5 and 3.8 but 4.1 made the diff and a/f confirms


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (autobahnjs)*

do you have the a/f curve for that...?...I'd be really interested in seeing that. http://****************.com/smile/emthup.gif


----------



## rychas1 (Mar 2, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

likewise







i wanna see too.


----------



## edubbleu (Feb 25, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (rychas1)*

wow! great thread! I'm just loving all the props about digi II now. I actually was bidding on a bmw afm just the other day before i read this...what an isnspiration this is gonna be. So the stock 3 bar fpr wont do nearly as good of a job as an adjustable one that goes up to 3.5-4.0 bar? Wont that decrease the mpg by a bunch?


----------



## mxman (Jul 31, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (edubbleu)*

AWESOME BRO!!!!! =D
too bad my car wont accept my vam, i tried hookign it up to my stock boot with duct tape, but no go...hmmmm just idles then dies DAMNH YOU CAR !!!







Did you have to reset the ECU?


----------



## H2091 (Apr 2, 2005)

*Re: food for thought...dyno plots of stock vs bmw VAM (mxman)*

I'm running an AMS chip (which does quite a bit to richen fuel mixture) won't this make my car run a bit too rich??


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (H2091)*

thats what I thought too...but look at my dyno...when I put the bmw on there with no change in fuel pressure...the motor went dramatically lean...just by upping the pressure by 5 psi...it helped...
ams programmed the chip to go rich...but that was based on a stock VAM parameters...








that VAM is a pretty significant size increase...


----------



## mxman (Jul 31, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

I seem to own the newer style Bmw 535 Airmeter, 0 280 203 016
interesting, i assume this isnt going to work, i had it wired up, i fired up the car with the spring at a bunch of different tensions with no success...suggestions ? I think I will map it with the ohm meter







!


----------



## ridefuel (Aug 9, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (mxman)*

Question, will this work with a digi 1 system?


----------



## autobahnjs (Sep 14, 2002)

*Re: food for thought...dyno plots of stock vs bmw VAM (ridefuel)*

digi 1 does not have a vaf meter...as far as i know


----------



## ridefuel (Aug 9, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (autobahnjs)*

um, I have an 89 Golf Gl, I have one of those, but I always thought my car was digi 1


----------



## username (Mar 27, 2001)

*Re: food for thought...dyno plots of stock vs bmw VAM (ridefuel)*

if its a california emissions golf than it is called digi 1 which has absolutely nothing to do with corrado g60 digi 1 (somebody at vw must have been asleep on that one)


----------



## ridefuel (Aug 9, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (username)*


_Quote, originally posted by *username* »_if its a california emissions golf than it is called digi 1 which has absolutely nothing to do with corrado g60 digi 1 (somebody at vw must have been asleep on that one)

Ahh, thanks for clearing that up.


----------



## killacoupe (Jun 3, 2002)

*Re: food for thought...dyno plots of stock vs bmw VAM (ridefuel)*

nice djsuperchink,i run about 58psi with g60 injectors,stock ecu and maf and it rips.I went 14.5 in my street car spining the slicks all thru first http://****************.com/smile/emthup.gif


----------



## ridefuel (Aug 9, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (killacoupe)*

can anyone give me a rough estimate of what price you guys find these for at junkyards?


----------



## username (Mar 27, 2001)

*Re: food for thought...dyno plots of stock vs bmw VAM (ridefuel)*

i got one from ebay for $45 shipped http://****************.com/smile/emthup.gif 
i just need to source an adjustable FPR.....question regarding that, how does a remote FPR (not on the end of the fuel rail) mate up to the fuel rail, do they come with the appropirate fittings?


----------



## Fast929 (Nov 13, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (username)*

Just a quick tidbit for you guys, watch out running over 4bar on bosch injectors, you'll actually start having issues closing them. If you need that much more fuel, I'd recommend some larger injectors. Verified by Scott W.
I'm sure many will work fine, just an FYI for you guys. Nice job on this too.... http://****************.com/smile/emthup.gif


----------



## username (Mar 27, 2001)

*Re: food for thought...dyno plots of stock vs bmw VAM (Fast929)*

just a guess here but i would imagine an 8v wouldn't need as much fueling as the car that was dyno'ed due to it having half the valves (and therefore less air in the combusion chambers)....thanks for the tip though http://****************.com/smile/emthup.gif


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Fast929)*


_Quote, originally posted by *Fast929* »_Just a quick tidbit for you guys, watch out running over 4bar on bosch injectors, you'll actually start having issues closing them. If you need that much more fuel, I'd recommend some larger injectors. Verified by Scott W.
I'm sure many will work fine, just an FYI for you guys. Nice job on this too.... http://****************.com/smile/emthup.gif 

I would really like to know which setup is better...
Bigger injectors with less pressure or standard ones with more pressure


----------



## Fast929 (Nov 13, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (Black_cabbie)*

Not necassarily aimed at the 8v guys as like mentioned, generally takes some work to get output higher than the std injection/injectors can handle. FI of course would fall under this prereq. 
Well, you really need to see what/where you are for output (hp). That's the main factor. The more you have, the larger the injectors you need. Too large and they get hard to modulate at idle. Too small and you run wayyyy past the duty cycle limit (preferred limit by the manufacturer) of about 85%. If your pushing 4bar and are still running duty cycle above 85%, it's time to start thinking about going with larger injectors. 
Some may disagree on this but you'll start to see failures running high pressure and big duty cycles. Pretty easy as there are a ton of factory injectors from bosch (vw stock) that have higher rates that drop in and work well.


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Fast929)*


_Quote, originally posted by *Fast929* »_Well, you really need to see what/where you are for output (hp). That's the main factor. The more you have, the larger the injectors you need. Too large and they get hard to modulate at idle. Too small and you run wayyyy past the duty cycle limit (preferred limit by the manufacturer) of about 85%. If your pushing 4bar and are still running duty cycle above 85%, it's time to start thinking about going with larger injectors. 


this is probably key...too large a pressure for small injectors means you'll spray fuel like crap when you need more precise delivery, but too small an injector for a set fuel pressure means you're taxing your current injectors...
here's a little formula to help.
To calculate an injector’s flow rate at a new desired fuel pressure you will need to the old fuel pressure in psi (x), new fuel pressure in psi , injector flow rate in #/hr.
square root of y
------------------ * flow rate of injectors = new flow rate
square root of x 

3.0bars = 43 psi (stock digiII fpr)
3.5bars = 50 psi
4.0bars = 58 psi
corrado green tops are 24#/hr = 244 cc/min
square root of 43 = 6.56
---------------------------- * 24# = 27# (these are rounded off...so approximate)
square root of 58 = 7.62
basically when pushing stock corrado green tops at 4 bar, we're really flowing equivalent to a 27# injector at stock pressure...
_note: this is just some of my random notes from researching on the internet, if any of it is wrong, and you know it, please feel free to correct me...thanks_
as for the 85% duty cycle part, I haven't read up to there yet so I can't comment..
I do know that at the level of pressure I'm at now, I am looking into getting larger injectors...don't know which yet though...


_Modified by DjSuperChink at 10:37 PM 4-14-2005_


----------



## ridefuel (Aug 9, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

nice info http://****************.com/smile/emthup.gif this seems to be a good way for me to do a little upgrade to the daily.


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (ridefuel)*

here's alittle bit about 85% duty cycle...injectors are rated at what ever fpr they came with usually 3 bar is the standard @ 100% duty cycle. for example, if an injector is a 24# injector it is rated to flow 24#/hr of fuel @ 43 psi (3 bar) at 100% duty cycle (how long it stays open)...
it is said you don't want to run your injectors at 100% duty cycle. If you run an injector above 85% duty cycle, you run the risk of locking up the injectors...
so some math can point me in the direction I need.
since at the fuel pressure I am at above puts me flowing at about 27#/hr. This is my desired flowed rate . My desired injector will be (x)
x * .85 = y
y = 27
------- = 32
.85
according to this I need a 32# injector to give me enough room so I am not running at 100%...
going the other way around because I noticed some 30# injectors for sale in the classifieds forum...
30 .85 = 26# which if needed, I could use and run the pressure a tiny bit higher



_Modified by DjSuperChink at 11:51 AM 4-15-2005_


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

by the way...alot of this information can be found on google...I just typed in "injector flow rates" "optimum injector flow" and similar search strings...and wholla...


----------



## Fast929 (Nov 13, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

Good info posted. Show's what I was talking about a little better. 








Better to run slightly over injected than under. Not the same beasts but my 1.9L 16v will be running 42lb green top bosch injectors once I get my motor done. Prolly overkill for you by a ways but there should easily be something you can find. Just check around on the FS threads and see what's out there. Scott Williams is a great guy for soursing injectors from amongst other fueling goodies as well.


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Fast929)*

This thread reminds me the first ever BMW Maf thread.... You know what I am talking about.








Good Info! 
PS. I just bought an adjustable rising rate FPR. Still looking for the AMF.


----------



## Fast929 (Nov 13, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (Black_cabbie)*

Another quick point here. You guys don't need rising rate fpr's for these applications. Set it and forget it. I'd run a std vw 4bar unit on a digi rail. Should be able to find one cheap....
Unless your looking to really dial your FP in. Then the adj would be the best option.
Just food for though.


_Modified by Fast929 at 8:48 AM 4-16-2005_


----------



## Peter Tong (Jun 17, 1999)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

Thats a nice gain in torque on the low end for just a VAM swap... (and this from a die hard CIS nut)... http://****************.com/smile/emthup.gif 
Looks like the stock VAM way overfuels on the bottom end... is this the case with the majority of Digi2 cars?


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Peter Tong)*


_Quote, originally posted by *Peter Tong* »_Looks like the stock VAM way overfuels on the bottom end... is this the case with the majority of Digi2 cars?

no. I am running an AMS remapped ecu. Its hard to verify since AMS does nto actively sell the unit anymore...but its said to richin the fuel mixture quite a bit.


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Fast929)*


_Quote, originally posted by *Fast929* »_Another quick point here. You guys don't need rising rate fpr's for these applications.


I second that point. adj fpr and static fpr aren't really static, as your engine revs, the pressure does change or rise but it does it in a linear increase...if you have a guage hooked up, you'll see about 5 psi change when the engine revs, thats why there's a vacuum port on fpr connected to the throttle body. This linear rise is associated with the higher revs needing more fuel
rising rate fprs were designed as a cheap alternative for force induction. as engine revs the fuel pressure will rise in a mulitplied factor to the standard rise...this increases fuel pressure to the injectors in a non-linear manner...this will will cause too much fuel to be dumped when your at high revs or wot...
a regular adj fpr is completely fine and a better alternative than a static fpr...but a rising rate one may not give you the best end results as the non-linear pressure change will make it hard to tune correctly.


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

So its better not to use the vaccum hose from the manifold to the FPR?


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Black_cabbie)*


_Quote, originally posted by *Black_cabbie* »_So its better not to use the vaccum hose from the manifold to the FPR? 

well...if you have a vacuum nipple on your manifold than you can use it...but since your throttle body has 2 vacuum niples, its easiest to just use the vacuum niples off the throttle body...
and yes, you NEED to have that vacuum line hooked up.


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

My engine is a 2H cabriolet Digifant. The manifold points to the other side of the engine bay. The FPR is right next to a nipple on the manifold. 








One more thing. How do connect the adjustable fpr to the fuel rail? 


_Modified by Black_cabbie at 12:37 AM 4-20-2005_


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Black_cabbie)*

on your engine...you would be best to hook up the vacuum tube to that spot...thats where the factory put it...
as to where to mount the adj fpr...its difficult for me to say because I am using a 16v and was forced to buy an aftermarket fuel rail...other 8v owners would have to jump in on this one...


----------



## edubbleu (Feb 25, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

show/tell us pics of how you mounted the afm!!!


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (edubbleu)*

Found these pics while searching....


----------



## edubbleu (Feb 25, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (edubbleu)*

oops...i meant with a [email protected]


----------



## qwikxr (Feb 9, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Fast929)*


_Quote, originally posted by *Fast929* »_Better to run slightly over injected than under. Not the same beasts but my 1.9L 16v will be running 42lb green top bosch injectors once I get my motor done. Prolly overkill for you by a ways but there should easily be something you can find. Just check around on the FS threads and see what's out there. 

42's?? Holy crap!
I run 42s @ 45psi WOT in my 2.3L 8v turbo @ 24psi on a Super 60, and Im rich as hell! lol!!


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (qwikxr)*

42lb injectors in a non turbo car.... Somebody will have a rough idle


----------



## Fast929 (Nov 13, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (Black_cabbie)*

84mm 12.5:1 pistons, 288 race cams, big valve head, itbs, and stand alone management,,
Ya, might be a little rough.....








On a serious note, I can control PWM amongst other things so I'm not really worried. You think a turbo car idling is making any boost? Runs just like a NA car at idle just with a little more back pressure. They still idle and I've seen wayyyyyy bigger injectors run there.
Have faith boys.....


----------



## qwikxr (Feb 9, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Fast929)*


_Quote, originally posted by *Fast929* »_84mm 12.5:1 pistons, 288 race cams, big valve head, itbs, and stand alone management,,
Ya, might be a little rough.....








On a serious note, I can control PWM amongst other things so I'm not really worried. You think a turbo car idling is making any boost? Runs just like a NA car at idle just with a little more back pressure. They still idle and I've seen wayyyyyy bigger injectors run there.
Have faith boys.....

I'd say you've got a nasty bizzatch there! http://****************.com/smile/emthup.gif
I know an idling turbo car is basically the same as an NA car. I was more referencing WOT conditions.. Hence my 42pph description of my 2.3L @ full boost!







You'll def. have to keep the PW down, as well as fuel pressure!








I'd pay a dollar to ride in it! http://****************.com/smile/emthup.gif Is it still going together, or done?


----------



## Fast929 (Nov 13, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (qwikxr)*

Well,,,, you might love me less once I tell you it's a 16v but thanks for the kind words.








Here's the full spec for anyone who cares.
1.8L PL based block bored to 84mm (1915cc in the end). 86.4mm (1.8L) crank lightened 3lbs, knife edged and balanced (using it for better rod ratio on a high rev NA motor over the 9a). Eurospec forged race rods (H-beam). 144mm long. Lightened/turned IM shaft with new 9a (36mm gear) oil pump. Custom Wiseco forged pistons. 84mm 12:5cr, coated skirts and pins, 315gr. 1.8L P+P big valve head. Supertech nitrided/undercut stem intakes and inconel undercut stem exhausts. Custom supertech "low profile" Ti retainers (for high lift cams). Supertech HD springs. Light weight lifters (47gr). TT 288 race cams. Piper adjustable cam gear. Custom equal length runner intake manifold running gsxr 1000 itb's. 125mm long v-stacks. Fully taper bored starting at 85mm ID at the horns down to the 42.5mm throttle plates in the itbs. Throttle plate to valve distance set to 205mm (secondary intake track pulse) and overall length of intake set at 14.75" long. ITG triple stage foam filter. Using 1.8T fuel rail with 3bar fpr and bosch green top 42lb injectors. TT 4-1 race header. Still working on the exhaust setup. Running megasquirt and spark extra for fueling/spark. Mated to a 2y tranny with peloquin LSD (looking at maybe going to 4.20r+p) with .89 5th. Clutch net sprung center 6 puck disk and DRS triple strap PP. 8.3lb flywheel.
Unfortunately it's not done,,, YET. I have everything I need minus a few little items. Block is still at the shop getting punched out but I have the rest pretty much done. Should go together pretty quickly once I get the block back.
And for anyone close enough, no dollar needed, come for a ride! http://****************.com/smile/emthup.gif


----------



## qwikxr (Feb 9, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Fast929)*


_Quote, originally posted by *Fast929* »_Here's the full spec for anyone who cares.
1.8L PL based block bored to 84mm (1915cc in the end). 86.4mm (1.8L) crank lightened 3lbs, knife edged and balanced (using it for better rod ratio on a high rev NA motor over the 9a). Eurospec forged race rods (H-beam). 144mm long. Lightened/turned IM shaft with new 9a (36mm gear) oil pump. Custom Wiseco forged pistons. 84mm 12:5cr, coated skirts and pins, 315gr. 1.8L P+P big valve head. Supertech nitrided/undercut stem intakes and inconel undercut stem exhausts. Custom supertech "low profile" Ti retainers (for high lift cams). Supertech HD springs. Light weight lifters (47gr). TT 288 race cams. Piper adjustable cam gear. Custom equal length runner intake manifold running gsxr 1000 itb's. 125mm long v-stacks. Fully taper bored starting at 85mm ID at the horns down to the 42.5mm throttle plates in the itbs. Throttle plate to valve distance set to 205mm (secondary intake track pulse) and overall length of intake set at 14.75" long. ITG triple stage foam filter. Using 1.8T fuel rail with 3bar fpr and bosch green top 42lb injectors. TT 4-1 race header. Still working on the exhaust setup. Running megasquirt and spark extra for fueling/spark. Mated to a 2y tranny with peloquin LSD (looking at maybe going to 4.20r+p) with .89 5th. Clutch net sprung center 6 puck disk and DRS triple strap PP. 8.3lb flywheel.
Unfortunately it's not done,,, YET. I have everything I need minus a few little items. Block is still at the shop getting punched out but I have the rest pretty much done. Should go together pretty quickly once I get the block back.
And for anyone close enough, no dollar needed, come for a ride! http://****************.com/smile/emthup.gif


----------



## emvee2003 (May 7, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

For the FPR you bought that was for the Supra, did the fuel rail adapter fit on your fuel rail?


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (emvee2003)*

Quick Update. 
Installed the bigger AFM last night. Adjusted the spring so that I have the exact same resistance as before. Car idles fine but as soon as you floor it, it misses and fallls on its face. Upped the pressure from 3 to 3.5. Much better but its still struggling to get there. 4bars make it ok high but runs pig rich at idle. I tried to adjusted the mixture but nomatter what I am either lean low/rich high or the other way arround. 
Any ideas?


----------



## rychas1 (Mar 2, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (Black_cabbie)*

adjust it more...form what i know, ull need to adjust it so that it doesnt fall from giving gas (correct vaccum pull) and i may havta play withthe idle screw to get i right. courtesy of gizmotoy1.


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (rychas1)*

Well, It will have to wait a few days. The oil pump siezed this morning


----------



## qwikxr (Feb 9, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (Black_cabbie)*

It's coming, george.. complete with sump seal! http://****************.com/smile/emthup.gif


----------



## Black_cabbie (Jul 16, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (qwikxr)*


_Quote, originally posted by *qwikxr* »_It's coming, george.. complete with sump seal! http://****************.com/smile/emthup.gif 

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


----------



## DjSuperChink (Sep 29, 2003)

*Re: food for thought...dyno plots of stock vs bmw VAM (emvee2003)*


_Quote, originally posted by *emvee2003* »_For the FPR you bought that was for the Supra, did the fuel rail adapter fit on your fuel rail?

Sorry I havent' been keeping up for awhile with this thread...
but since I am running a 16v digi, I had to buy one of thos ross machine fuel rails...so my method won't be like your method for the 8v heads...but the supra adj fuel pressure kit comes with this generic adapter plate that would bolt to the fuel rail in place of where the stock fpr bolts to and gives you one of those fuel tube fittings so you can hook up a fuel line to it running to the fpr...
as soon as I get some time, I will take pics and you'll understand better.


----------



## 16V VW (Aug 1, 2004)

*Re: food for thought...dyno plots of stock vs bmw VAM (DjSuperChink)*

Page 3 pw3nd
haha, it's been 2 year since i've done this mod and this is the first thread i've seen.
it's about time somebody did this right.
rychas1 u ever get yours running?


----------

