# injector theory on a vr6 turbo



## jimvr6 (Apr 30, 2004)

ok i been hearing alot of different stuff about vr6 injectors on a vr6 turbo like they can support up to 15 pounds of boost

is this true and if not how much can boost can they support

thanks


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## mattstacks (Jul 16, 2002)

*Re: injector theory on a vr6 turbo (jimvr6)*

Its hard to say..
Without additional pressure via a rising rate fpr, then i would say less than ten.
If you are running 200PSI fuel rail pressure then you can go to 15 or so.


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## Scott F. Williams (Oct 14, 2000)

*Re: injector theory on a vr6 turbo (jimvr6)*


_Quote, originally posted by *jimvr6* »_ok i been hearing alot of different stuff about vr6 injectors on a vr6 turbo like they can support up to 15 pounds of boost
is this true and if not how much can boost can they support

If you crank the hell out of the fuel pressure with an FMU, you can force teeny injectors to do the job of properly-sized injectors. That's a sloppy method and is essentially mechanical torture. Bosch recommends that their injectors be run at no more than 5bar pressure at the fuel rail. If you're running 15psi, that'd mean that a 4bar regulator is as much as they'd consider safe for long-term operation.
Folks on Vortex have demonstrated that the high-pressure/little injector method can work. But... there is a big difference between what's feasible and what is technically ideal. Considering how cheap bigger injectors are and the prevalence of good chips to manage them, there is no good reason at all to do a hack job with an FMU.


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## Scooter98144 (Jul 15, 2002)

*Re: injector theory on a vr6 turbo (Scott F. Williams)*

What I like is the idea of adding bigger injectors with a chip that is well tunned for them. Then latter if you need a tad more fuel then a bit more fuel pressure is not so bad. 
I may try just this with my AMS kit. Unless some one come out with a good OBD1 42 chip that is.
Just a thought.


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## Ohio Brian (Aug 13, 2001)

*Re: injector theory on a vr6 turbo (Scooter98144)*


_Quote, originally posted by *Scooter98144* »_ Unless some one come out with a good OBD1 42 chip that is.


Workin on it


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## SKULLNICK (Oct 26, 2002)

*Re: injector theory on a vr6 turbo (Ohio Brian)*

fmu's are stupid. only hacks use them.


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## GTRTim (Jun 28, 2003)

*Re: injector theory on a vr6 turbo (SKULLNICK)*


_Quote, originally posted by *SKULLNICK* »_fmu's are stupid. only hacks use them.

LMAO... Thats funny cause last time I checked... The people who have the WORLDS Quickest and Fastest FWD VW and the Worlds Quickest and Fastest VW Street Car, used FMU's on there cars for a long time before going to standalone... I guess... 10's with a FMU = HACK....
You say there is plenty of "Good" chip tuning for Big Injectors... Well if there was I'd have it in my car.... but I have yet to see anything that has shown performance and drivabilty that is better then our FMU setup.


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## BORA-Nos (Jun 13, 2001)

*Re: injector theory on a vr6 turbo (GTRTim)*


_Quote, originally posted by *GTRTim* »_
LMAO... Thats funny cause last time I checked... The people who have the WORLDS Quickest and Fastest FWD VW and the Worlds Quickest and Fastest VW Street Car, used FMU's on there cars for a long time before going to standalone... I guess... 10's with a FMU = HACK....
You say there is plenty of "Good" chip tuning for Big Injectors... Well if there was I'd have it in my car.... but I have yet to see anything that has shown performance and drivabilty that is better then our FMU setup.

Couldn't have said it ant better myself http://****************.com/smile/emthup.gif .


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## BigDaddyCW (Apr 4, 2000)

*Re: injector theory on a vr6 turbo (Ohio Brian)*


_Quote, originally posted by *Ohio Brian* »_
Workin on it
















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


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## eiprich (Mar 4, 2003)

*Re: injector theory on a vr6 turbo (BORA-Nos)*


_Quote, originally posted by *BORA-Nos* »_
Couldn't have said it ant better myself http://****************.com/smile/emthup.gif .

Ditto
-Rich


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## Scooter98144 (Jul 15, 2002)

*Re: injector theory on a vr6 turbo (eiprich)*

Is there any diffrences running a FMU at the track over a daily driver that sees all sorts of diffrent temps and loads?


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## eiprich (Mar 4, 2003)

*Re: injector theory on a vr6 turbo (Scooter98144)*


_Quote, originally posted by *Scooter98144* »_Is there any diffrences running a FMU at the track over a daily driver that sees all sorts of diffrent temps and loads? 


No, they function the same under any temp. 
We use them almost exclusively on daily driven street cars and unless you are prepared to spend big money on stand-alone, an FMU combined with a proper ECU upgrade (like the EIP Turbo Chips) is the most proven and tested method to gain excellent power, torque and retain oem like driveability. 
We have lots of folks who are now expanding on this idea and adding larger injectors (42lb units - $59 each) along with our large MAF housing ($149) and then re-tuning the FMU to allow an even broader range of adjustment on 4 and 6 cyl VW's. This is always an option but requires much more time then just sticking with the stock units which we have proven (along with the GTR guys and countless others) are good to 300-350+ whp reliably. 
-Rich


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## fastslc (Sep 14, 1999)

*Re: injector theory on a vr6 turbo (eiprich)*

Rich,
What is the success rate of using the alternative combo that you just mentioned above ? 
Does the chip require more tweaking ? Or "merely" retweaking the FMU ?
Thanks
d


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## eiprich (Mar 4, 2003)

*Re: injector theory on a vr6 turbo (fastslc)*


_Quote, originally posted by *fastslc* »_Rich,
What is the success rate of using the alternative combo that you just mentioned above ? 
Does the chip require more tweaking ? Or "merely" retweaking the FMU ?
Thanks
d

We have many cars using this combo, lots of 4cyl and a growing number of VR6's. No change to our Turbo Eprom is needed as the MAF housing recalibrates the signal to work with the larger injectors and the current maps. 
Tuning the billet FPR is usually all that is needed, and we often disable the OEM FPR on the rail to allow a lower base pressure at idle. 
-Rich


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## Scooter98144 (Jul 15, 2002)

*Re: injector theory on a vr6 turbo (eiprich)*

This may be what I end up doing as well. I have a ATP chip that was written for 32lb injectors with a 3" MAF. So now that I have added more boost as well as an intercooler I have a feeling that I need more fuel.
Rather than paying several hundred dollars for a new chip then a couple hundred more for a larger MAF and a few hundred more for bigger injectors.
I went and got a wide band then latter I can toss in a piggy back pump and a FMU and tweak it using the wide band.
With data logging of the EGT, boost, RPM, Throttle position, and maybe timming. I could then maybe get ATP to tweak any thing else for a small fee. Like having the timing changed or what ever else needed tweaking.
Just one idea.
Just a thought.


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## I am Jack's VR6 (Sep 18, 2001)

*Re: injector theory on a vr6 turbo (eiprich)*


_Quote, originally posted by *eiprich* »_
Tuning the billet FPR is usually all that is needed, and we often disable the OEM FPR on the rail to allow a lower base pressure at idle. 
-Rich

Nobody at EIP has ever mentioned anything like that to me, and I'm kind of curious why... Especially if it's a normal thing for you guys to do for people running the stage 2 fueling.
All it does is lower the base at idle?


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## HIGH PSI (May 17, 2003)

*Re: injector theory on a vr6 turbo (I am Jack's VR6)*

I believe he is referring to people with larger injectors, not just stage II.


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## eiprich (Mar 4, 2003)

*Re: injector theory on a vr6 turbo (I am Jack's VR6)*


_Quote, originally posted by *I am Jack's VR6* »_Nobody at EIP has ever mentioned anything like that to me, and I'm kind of curious why... Especially if it's a normal thing for you guys to do for people running the stage 2 fueling.
All it does is lower the base at idle?

Thats because you do not want to disable the OEM FPR as you are not running our MAF / 42 lb/hr setup...
...with a little fine tuning your current setup will be fine. 
-Rich


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## MeanieMe (Jul 20, 2001)

*Re: injector theory on a vr6 turbo (HIGH PSI)*

So let me get this right.
I can run my stock 3.bar FPR on my 2.0 ABA boosted. BUT!!!
I'll be OK with stand alone even with some 6++ injectors?


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## eiprich (Mar 4, 2003)

*Re: injector theory on a vr6 turbo (MeanieMe)*


_Quote, originally posted by *MeanieMe* »_So let me get this right.
I can run my stock 3.bar FPR on my 2.0 ABA boosted. BUT!!!
I'll be OK with stand alone even with some 6++ injectors?

Sorry I am not tracking your question...can you re-phrase this?
-Rich


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## eiprich (Mar 4, 2003)

*Re: injector theory on a vr6 turbo (HIGH PSI)*


_Quote, originally posted by *HIGH PSI* »_I believe he is referring to people with larger injectors, not just stage II.

Exactly
-Rich


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## MeanieMe (Jul 20, 2001)

*Re: injector theory on a vr6 turbo (eiprich)*


_Quote, originally posted by *eiprich* »_
Sorry I am not tracking your question...can you re-phrase this?
-Rich

OK
I bought a car with the turbo & stand alone already in it. 
As for the mechanical problems I've fixed & noticed that it's running 660cc injectors, I believe. BUT I noticed that there's only a stock ABA 3Bar FPR. 
Now is this an issue that I should consider a 4.bar Fuel pressure regulator. Or because it has a Haltech standalone and a Supra fuel pump makes getting a different FPR useless.


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## eiprich (Mar 4, 2003)

*Re: injector theory on a vr6 turbo (MeanieMe)*


_Quote, originally posted by *MeanieMe* »_
OK
I bought a car with the turbo & stand alone already in it. 
As for the mechanical problems I've fixed & noticed that it's running 660cc injectors, I believe. BUT I noticed that there's only a stock ABA 3Bar FPR. 
Now is this an issue that I should consider a 4.bar Fuel pressure regulator. Or because it has a Haltech standalone and a Supra fuel pump makes getting a different FPR useless.


This is way OT but I will answer anyway...
The injectors are generally rated at 43psi which is close to 3 bar (44.1psi) so at that pressure you have enough fuel for 450HP which would yield about 380WHP. 
The OEM FPR will rise with boost at close to 1:1 which is ideal for most all stand-alone system so you should be just fine provided everything else is up to task on your fuel system and other management components. 
-Rich


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## SKULLNICK (Oct 26, 2002)

*Re: injector theory on a vr6 turbo (GTRTim)*

i have never seen another car with an fmu besides a vw. everything that goes faster than those particular cars don't use them no matter what the make. a 9 or 10 second car was cool about 30 years ago, get over it chief. vw's simply don't make good drag cars, unless they are bugs.


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## I am Jack's VR6 (Sep 18, 2001)

*Re: injector theory on a vr6 turbo (HIGH PSI) (eiprich)*

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


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## I am Jack's VR6 (Sep 18, 2001)

*Re: injector theory on a vr6 turbo (SKULLNICK)*


_Quote, originally posted by *SKULLNICK* »_i have never seen another car with an fmu besides a vw. everything that goes faster than those particular cars don't use them no matter what the make. a 9 or 10 second car was cool about 30 years ago, get over it chief. vw's simply don't make good drag cars, unless they are bugs.

Are you kidding me? There are 50 times as many boosted Honda's that run FMU's.


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## extremsplvr6 (Mar 26, 2003)

*Re: injector theory on a vr6 turbo (I am Jack's VR6)*

Lt1 and Ls1 also. Look at any vortec s/c kit for them....
Just put on two kits on two Lt1's...


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## GTRTim (Jun 28, 2003)

*Re: injector theory on a vr6 turbo (SKULLNICK)*


_Quote, originally posted by *SKULLNICK* »_i have never seen another car with an fmu besides a vw. everything that goes faster than those particular cars don't use them no matter what the make. a 9 or 10 second car was cool about 30 years ago, get over it chief. vw's simply don't make good drag cars, unless they are bugs.

Dude... you are soooooooooooooooo clueless it's not even funny....
Really I can name 2 honda's from 5 minutes way from us that ran 10's on stock block/stock ecu + fmu and vafc so obviously other cars do run fmu's also....
Really a 9-10second import was cool about 30years ago ?? Consider that FWD Imports just broke into the 9 and 10's in RACE CARS 96-97 years ago, and FWD Import Street Cars broke into the 9's 2 years ago... um... yea i'd have to say 9-10's out of a FWD car is plenty impressive.


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## keith_r2 (Feb 7, 2002)

*Re: injector theory on a vr6 turbo (mattstacks)*


_Quote, originally posted by *mattstacks* »_Its hard to say..
If you are running 200PSI fuel rail pressure then you can go to 15 or so. 

200PSI fuel rail pressure !!! Scary stuff, but it works


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## eiprich (Mar 4, 2003)

*Re: injector theory on a vr6 turbo (keith_r2)*


_Quote, originally posted by *keith_r2* »_
200PSI fuel rail pressure !!! Scary stuff, but it works









120psi max rail pressure (and only under full boost) is what we usually run with our Stage-2 Fuel System and you can run 15psi all day long. 
Gotta have the right plugs and the right compression but other than that your good to go, the injectors and lines will last a long time. 
-Rich
Edit: you must remember that during most driving conditions, boost is low or non-existent thus fuel pressure is low like it is stock. It is only when you spool up the turbo (lots of throttle input) and run well into the boost that you will see the higher fuel pressures. I would bet that on my normal drive to work I only run in boost (thus higher fuel pressure) for a minute or two total. Fuel pressure is the same as stock all other times. 



_Modified by eiprich at 4:52 PM 8-5-2004_


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## fastslc (Sep 14, 1999)

*Re: injector theory on a vr6 turbo (eiprich)*

Regarding pressure in the lines - For a road racing application or extended WOT, it's not recommended..?


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## eiprich (Mar 4, 2003)

*Re: injector theory on a vr6 turbo (fastslc)*


_Quote, originally posted by *fastslc* »_Regarding pressure in the lines - For a road racing application or extended WOT, it's not recommended..?

As long as you watch EGT or AFR you should be just fine. 
-Rich


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## SKULLNICK (Oct 26, 2002)

*Re: injector theory on a vr6 turbo (GTRTim)*

i am talking about cars in general, yes there are other cars than vw's. a lot of nerds on here don't realise that. it might have something to do with jamming 150 psi through ancient g60 injectors. it might work, but i believe it to be an easy way out. why would you put something through mechanical torture like that. any engineer would agree that it is stupidity. i don't see how some companies would even recomend something like that.


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## Ohio Brian (Aug 13, 2001)

*Re: injector theory on a vr6 turbo (SKULLNICK)*

It's a matter of preference. 
THe FMU/injector combo is the old tried and true method. It's been around on all cars for years. It's also much "easier" for most people to adjust an FMU than to get into an ecu, find the fuel maps, edit them, and make a chip.
Now that there is good big injector software for our cars out there(there wasn't 3 years ago), everyone has an option.


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## Scrubby_4 (Aug 5, 2004)

*Re: injector theory on a vr6 turbo (eiprich)*

I would bet that on my normal drive to work I only run in boost (thus higher fuel pressure) for a minute or two total.
Gettin old Rich?







Come on tell the truth, boost is addictive ,and I think YOU are one of the biggest junkies. 
If your only in boost for maybe 2 mins. then you must live right next door to work. http://****************.com/smile/emthup.gif


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## I am Jack's VR6 (Sep 18, 2001)

*Re: injector theory on a vr6 turbo (fastslc)*


_Quote, originally posted by *fastslc* »_Regarding pressure in the lines - For a road racing application or extended WOT, it's not recommended..?

I know a semi-local guy that used to road-race his corrado all the time @ ~10psi/300whp. He was running EIP's stage 2 full kit and he never had any problems with the pressure.


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## GTRTim (Jun 28, 2003)

*Re: injector theory on a vr6 turbo (SKULLNICK)*


_Quote, originally posted by *SKULLNICK* »_i am talking about cars in general, yes there are other cars than vw's. a lot of nerds on here don't realise that. it might have something to do with jamming 150 psi through ancient g60 injectors. it might work, but i believe it to be an easy way out. why would you put something through mechanical torture like that. any engineer would agree that it is stupidity. i don't see how some companies would even recomend something like that.

What are you talking about ??? 
I hope your not reffering to us (GTR) ....
Jamming 150-200psi through a G60 injector works and is a cheap alternative for people who can't afford 3,000 for Standalone, Injectors, Fuel Rail and Fuel Lines......
We've pushed the limits with the FMU and Standalone... take your choice.... I guess thats cause we are retarded idiots ???


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## fastslc (Sep 14, 1999)

*Re: injector theory on a vr6 turbo (GTRTim)*

Good info here. Let's keep this civil. 
OK - let's assume mechanical "torture" is OK for now. 
If I want my max boost at 11 psi and no more than 300 crank hp.
What's better: IF I use the following combo recommended by EIP and many GTR crew
1. EIP Chip + Pump + Stock MAF + Stock Injectors
or 
2. EIP Chip + Pump + Stock MAF + Green Top G60 injectors + Retuned FMU 
The 2nd combo will allow me to have a tad more head room on the injector flow coz the G60 injectors are larger - hence allowing me to run less pressure in turn reducing the amount of mechanical torture. 
EDIT: How much more headroom would this buy me ??
DON'T BRING the C2 setup for now because it's NOT available for OBD1 Distributor. 
Thanks
d


_Modified by fastslc at 7:52 AM 8-8-2004_


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## I am Jack's VR6 (Sep 18, 2001)

*Re: injector theory on a vr6 turbo (fastslc)*

The EIP setup is consistent up until about 15 psi with the stock injectors. If you only want to run 11, why buy injectors you don't need?


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## fastslc (Sep 14, 1999)

*Re: injector theory on a vr6 turbo (I am Jack's VR6)*

Jack VR6,
I fully understand that EIP (which I may add has been great at answering my ?) has good success with the stockers. But in my mind if
for $200 extra by buying the G60 injectors will buy me ~15% more headroom, then it's not an issue.
Anymore feedback well appreciated regarding Green Top G60 injectors versus VR6 injectors
Thanks
d


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## eiprich (Mar 4, 2003)

*Re: injector theory on a vr6 turbo (fastslc)*


_Quote, originally posted by *fastslc* »_Jack VR6,
I fully understand that EIP (which I may add has been great at answering my ?) has good success with the stockers. But in my mind if
for $200 extra by buying the G60 injectors will buy me ~15% more headroom, then it's not an issue.
Anymore feedback well appreciated regarding Green Top G60 injectors versus VR6 injectors
Thanks
d

At the power level you want to run, the oem injectors work great, when coupled with our fuel system, they can easily deliver the fuel you will need for the power level and boost you plan to run. 
The 42 lb. (Green top) injector setup is ok but it requires more adjustments and tuning whereas our Stage-2 when installed correctly and all being in good shape is usually very straight forward. 
Whenever we can we run our basic Stage-2 as it provides seamless drivability and transitions to boost. It is also has a nice clean idle and runs like stock off boost, and in most situations, very smooth on boost. If we were doing your car in house, we would install and run our Stage-2 fuel System upgrade without a doubt. 
-Rich


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## I am Jack's VR6 (Sep 18, 2001)

*Re: injector theory on a vr6 turbo (eiprich)*

He's talking about running the 240 G60 injectors Rich.
fastslc -
In the end it's up to you. Be forewarned though, all the little crap you have to buy adds up quickly. That $200 that you could save from buying new injectors could be used elsewhere with more result. If you are on a budget, stick with the stock injectors.
Also, something that I noticed when I used to run 240 injectors was a slight dip in power at around 5500 rpm. That's non-existant with the stock injectors, which is what Rich is talking about.


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## MiamiVr6T (Jul 24, 2004)

*Re: injector theory on a vr6 turbo (I am Jack's VR6)*

so the car with the eip chip runs better/harder with stock injectors as opposed to the G60 injectors?


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## I am Jack's VR6 (Sep 18, 2001)

*Re: injector theory on a vr6 turbo (MiamiVr6T)*


_Quote, originally posted by *MiamiVr6T* »_so the car with the eip chip runs better/harder with stock injectors as opposed to the G60 injectors?

It runs just as hard, but it's much smoother. I don't see the need for larger G60 injectors unless you want to run over 15 psi with the EIP setup, but that's just one mans opinion.


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## MiamiVr6T (Jul 24, 2004)

*Re: injector theory on a vr6 turbo (I am Jack's VR6)*

so did GTR use the stock injectors or the G60's is what im wondering?


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## MiamiVr6T (Jul 24, 2004)

*Re: injector theory on a vr6 turbo (MiamiVr6T)*


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