Boost referenced fule pressure regulators....STS guys might want to read this.
06-19-2006, 12:32 AM
#1
12 Second Club
Thread Starter
iTrader: (6)
Join Date: Jun 2004
Location: Ft. Irwin, California (But Virginia is home)
Posts: 1,501
Likes: 0
Received 7 Likes
on
1 Post
Boost referenced fule pressure regulators....STS guys might want to read this. Passing on some info from the past month. I took the car to the dyno a couple weeks ago to see what the ol' STS was putting out. I have a FMIC, TR224 cam, LT's, and STS set to 5PSI as the "major" power adding mods.
Here's what I discovered. After I first installed the system I was like "damn, this car pulls like a freight train". After a couple weeks it didn't feel so strong. I figured I was getting used to the power. No. The computer was altering the tuning parameters.
I have 42lb injectors, a Racetronix 255gph pump and hotwire kit, but I learned the car is starving for fuel under positive boost. The tuning is very good (custom done by a knowledgeable friend on HP tuners), but once postive boost is encountered, even the 42lb injectors are fighting to deliver enough fuel against the boost pressure.
My origonal dyno run was 371RWHP....4HP less than with the cam and LT's. We saw that the long term fuel tables were adding fuel to compensate for positive boost loads. We tested the fuel vs. boost starvation theory by turning off the long-term fuel limiting....allowing the injecotrs to do what they wished. RWHP instantly jumped by +55 to 426RWHP. That's a difference that can be felt! The injectors were operating at low loads until boost was encountered, where the spiked pward in duty cycle in accordance with boost pressure.
So, the answer is't a computer keystroke, but delivering more fuel when in positive boost. Many front mount turbo members already know this and run return style fuel systems with boost referenced fuel pressure regulators. Seems that the rear mount crowd might want to consider this too.
I and my good friend CAT3 are in the process of converting my car to a return style fuel system that uses an Aeromotive boost referenced fuel pressure regulator. The difference between this and some available aftermarket systems is that he devised a nifty routing that uses the stock feed line AND RETURN PORT to eliminae cutting into the gas tank or lines. We are documenting this install and will provide detailed instructions once the project is completed.
Long story short, I should have sufficient fuel and be up +55RWHP once I get this mod completed. It's power I didn't know I was missing!!
Thought ya'll might be interested in this.
Here's what I discovered. After I first installed the system I was like "damn, this car pulls like a freight train". After a couple weeks it didn't feel so strong. I figured I was getting used to the power. No. The computer was altering the tuning parameters.
I have 42lb injectors, a Racetronix 255gph pump and hotwire kit, but I learned the car is starving for fuel under positive boost. The tuning is very good (custom done by a knowledgeable friend on HP tuners), but once postive boost is encountered, even the 42lb injectors are fighting to deliver enough fuel against the boost pressure.
My origonal dyno run was 371RWHP....4HP less than with the cam and LT's. We saw that the long term fuel tables were adding fuel to compensate for positive boost loads. We tested the fuel vs. boost starvation theory by turning off the long-term fuel limiting....allowing the injecotrs to do what they wished. RWHP instantly jumped by +55 to 426RWHP. That's a difference that can be felt! The injectors were operating at low loads until boost was encountered, where the spiked pward in duty cycle in accordance with boost pressure.
So, the answer is't a computer keystroke, but delivering more fuel when in positive boost. Many front mount turbo members already know this and run return style fuel systems with boost referenced fuel pressure regulators. Seems that the rear mount crowd might want to consider this too.
I and my good friend CAT3 are in the process of converting my car to a return style fuel system that uses an Aeromotive boost referenced fuel pressure regulator. The difference between this and some available aftermarket systems is that he devised a nifty routing that uses the stock feed line AND RETURN PORT to eliminae cutting into the gas tank or lines. We are documenting this install and will provide detailed instructions once the project is completed.
Long story short, I should have sufficient fuel and be up +55RWHP once I get this mod completed. It's power I didn't know I was missing!!
Thought ya'll might be interested in this.
06-19-2006, 12:50 AM
#3
12 Second Club
Thread Starter
iTrader: (6)
Join Date: Jun 2004
Location: Ft. Irwin, California (But Virginia is home)
Posts: 1,501
Likes: 0
Received 7 Likes
on
1 Post
Originally Posted by Boostaholic
What was the WBo2 reading under your lean condition? I would be more worried about that than 55hp
06-19-2006, 01:45 AM
#5
9 Second Club
iTrader: (2)
Join Date: Jun 2005
Location: Reston, VA
Posts: 2,034
Likes: 0
Received 0 Likes
on
0 Posts
Ehhhh.... 11.5 is safe... 12 I dont think is too dangerous. But all he needs is one hickup and he would would starve it out.
A+ Schantan... nice info share!!! I am also doing a complete re-do on my fuel system cause the 42's starve her. When I go 370 / 408 I will go -8AN from the tank, new fuel rails, and use the stock lines as the return. Good info on the FPR too!
A+ Schantan... nice info share!!! I am also doing a complete re-do on my fuel system cause the 42's starve her. When I go 370 / 408 I will go -8AN from the tank, new fuel rails, and use the stock lines as the return. Good info on the FPR too!
06-19-2006, 10:44 AM
#6
Originally Posted by longrange4u
Ehhhh.... 11.5 is safe... 12 I dont think is too dangerous. But all he needs is one hickup and he would would starve it out.
Schantin, what happened to your car is not uncommon. It's usually caused by oil getting on the maf from it leaking past the seals in the turbo. Oil on maf = reads less air = lean = LTFT's compensate by going positive.
If your driveay is inclined back in so the nose of the car is lower. I've had issues with the drain line back flowing into the turbo through the pump.
Trending Topics
06-19-2006, 09:18 PM
#8
9 Second Club
iTrader: (2)
Join Date: Jun 2005
Location: Reston, VA
Posts: 2,034
Likes: 0
Received 0 Likes
on
0 Posts
What do I know... My numbers are great but I am the one with the blown headgasket. I think I always ran leaner than I should have. I still think the thread is great info... but you guys are right... 11.0 is ideal... or you end up shopping short-blocks like me.
06-19-2006, 09:24 PM
#9
Restricted User
iTrader: (9)
Join Date: Sep 2002
Location: Sierra Vista, AZ
Posts: 7,603
Likes: 0
Received 0 Likes
on
0 Posts
Thought I'd chime in here since Phil let me know about this post.
Ok, the HPT PE table is set for a nice richer than 11:1 AFR, however, as stated and many more have seen, when your boosting and not adding the extra FP to compensate for it, you end up getting leaner throughout the rpm range. To fix that, we are adding the front mount BR-FPR as mentioned, and should have it all wrapped up Wed or Thurs this week, just waiting on a couple pieces to arrive, so as stated we dont have to cut into the fuel pump module or tank. I know the stock fuel line will support over 600rwhp, which wont be done too often on a stock bottom, so he will be more than good with stock feed line, and new 6AN return.
As for the LTFT's, Phil had a major oiling issue, mostly from when he first got the kit the tubing was already soaked in oil, but there was a seal leaking issue as well. During all that time the computer has had to relearn the Trims, which now its all clean the trims are off. The PCM was adding 12-17% Fueling ontop of what was programmed, so it was basically trying to run in the 9:1afr range, and that just dont work to well sometimes if the rest of the combo and tune are not setup for it. I will check the trims when we finish the return line and see where that stands. But until he gets back from Iraq, the setup will be more than adequate supply, return, pressure and flow, as well as look pretty damn good. Once he gets back I may end up flying back down here (I am moving end of this month) and help him with his 2 or 3 Bar SD Tuning, although I have a feeling our buddy Brian will be able to help him quite nicely with that as well. I'd love to see this project thru to the end, but another issue, we dont have a track here anymore...hopefully that too will be resolved when he gets home.
So far its been a great experience working with Phil on this return, and has given me a chance to teach him about the cars, and him teach me about patience and attention to detail.
Ok, the HPT PE table is set for a nice richer than 11:1 AFR, however, as stated and many more have seen, when your boosting and not adding the extra FP to compensate for it, you end up getting leaner throughout the rpm range. To fix that, we are adding the front mount BR-FPR as mentioned, and should have it all wrapped up Wed or Thurs this week, just waiting on a couple pieces to arrive, so as stated we dont have to cut into the fuel pump module or tank. I know the stock fuel line will support over 600rwhp, which wont be done too often on a stock bottom, so he will be more than good with stock feed line, and new 6AN return.
As for the LTFT's, Phil had a major oiling issue, mostly from when he first got the kit the tubing was already soaked in oil, but there was a seal leaking issue as well. During all that time the computer has had to relearn the Trims, which now its all clean the trims are off. The PCM was adding 12-17% Fueling ontop of what was programmed, so it was basically trying to run in the 9:1afr range, and that just dont work to well sometimes if the rest of the combo and tune are not setup for it. I will check the trims when we finish the return line and see where that stands. But until he gets back from Iraq, the setup will be more than adequate supply, return, pressure and flow, as well as look pretty damn good. Once he gets back I may end up flying back down here (I am moving end of this month) and help him with his 2 or 3 Bar SD Tuning, although I have a feeling our buddy Brian will be able to help him quite nicely with that as well. I'd love to see this project thru to the end, but another issue, we dont have a track here anymore...hopefully that too will be resolved when he gets home.
So far its been a great experience working with Phil on this return, and has given me a chance to teach him about the cars, and him teach me about patience and attention to detail.
06-19-2006, 11:30 PM
#10
9 Second Club
iTrader: (2)
Join Date: Jun 2005
Location: Reston, VA
Posts: 2,034
Likes: 0
Received 0 Likes
on
0 Posts
Why did you increase the return size instead if doing a -8AN feed line and using the old stock feed as the return?
Last edited by longrange4u; 06-20-2006 at 01:05 AM. Reason: mispelling
06-19-2006, 11:31 PM
#11
Restricted User
iTrader: (9)
Join Date: Sep 2002
Location: Sierra Vista, AZ
Posts: 7,603
Likes: 0
Received 0 Likes
on
0 Posts
The return size is not increased. Stock line is 3/8" or 6AN, same size really.
*edit...adding: Besides, I need to convince him to buy another intank, and -8 or -10 feed line later
*edit...adding: Besides, I need to convince him to buy another intank, and -8 or -10 feed line later
Last edited by CAT3; 06-20-2006 at 02:33 AM.
06-20-2006, 01:30 AM
#13
Restricted User
iTrader: (9)
Join Date: Sep 2002
Location: Sierra Vista, AZ
Posts: 7,603
Likes: 0
Received 0 Likes
on
0 Posts
Hopefully by Wed or Thursday I can post the finalized list of parts with prices and PN's. Only difference b/w the list and what we're using on Phils car is the Earl's Billet Y Block, I am listing all parts from one major supplier, Summit, and he ended up getting a NOS 6AN Y Fitting. Also, I am waiting to confirm one of two 6AN to Metric fittings that will be used to block off the stock return line so there is no back feeding of fuel in the stock feed line. Other than that, I have the list complete, price comes out to about $380 and does not include the following: Pump, Rails, Regulator. Essentially its just the hose and one gillion fittings... It seems most ppl already have a fuel pump, and rails some like brand A, some like B. Same with the Regulator. Phil is using an Aeromotive, nice pump, decent size, but uses O-ring AN Fittings (simply slip an O-ring on the fitting, but still caught me by surprise).
06-20-2006, 06:08 PM
#14
12 Second Club
Thread Starter
iTrader: (6)
Join Date: Jun 2004
Location: Ft. Irwin, California (But Virginia is home)
Posts: 1,501
Likes: 0
Received 7 Likes
on
1 Post
Still waiting on the UPS man with my parts to get things finished.... but I can clarify a couple responses to this thread.
1. For Zombie....yes, I had oil in the intake pipe and on the MAF at one time, and this probably did set off the LTFT tables. I had the oil pump wiring installed with the STS supplied clips, and it did not provide a good connection, setting off the oil buzzer. Since then I soldered the wires and replaced the MAF and have had no further issues. This was a very good point, though. It clued me in to reflash the STS tune I have to reset the parameters once the fuel system is completed. This should prevent future LTFT enrichment that's not necessary.
2. I saw some comments on the A/F ratio being a bit high. That's the whole point of this thread! The 42lb injectors are fighting against the boost pressure to deliver fuel. The A/F is set to a very conservative 11.0 to 1. It runs that....until high RPM. The injectors begin cycling more than expected (about 17.4) once full boost is obtained. The point here is that a boost referenced FPR will increase the fuel pressure on a 1:1 ratio with boost, so I'll be getting an extra 5lbs of fuel pressure at 5psi. Then the injectors won't be working overdrive, I'll maintain the 11.0 to 1 A/F ratio....and power production will increase.
Anyhow, should have this project wrapped up by Thursday or Friday. I'll post on the outcome and put up a couple pics then. How-to guide will follow providing we meet with success.
1. For Zombie....yes, I had oil in the intake pipe and on the MAF at one time, and this probably did set off the LTFT tables. I had the oil pump wiring installed with the STS supplied clips, and it did not provide a good connection, setting off the oil buzzer. Since then I soldered the wires and replaced the MAF and have had no further issues. This was a very good point, though. It clued me in to reflash the STS tune I have to reset the parameters once the fuel system is completed. This should prevent future LTFT enrichment that's not necessary.
2. I saw some comments on the A/F ratio being a bit high. That's the whole point of this thread! The 42lb injectors are fighting against the boost pressure to deliver fuel. The A/F is set to a very conservative 11.0 to 1. It runs that....until high RPM. The injectors begin cycling more than expected (about 17.4) once full boost is obtained. The point here is that a boost referenced FPR will increase the fuel pressure on a 1:1 ratio with boost, so I'll be getting an extra 5lbs of fuel pressure at 5psi. Then the injectors won't be working overdrive, I'll maintain the 11.0 to 1 A/F ratio....and power production will increase.
Anyhow, should have this project wrapped up by Thursday or Friday. I'll post on the outcome and put up a couple pics then. How-to guide will follow providing we meet with success.
06-21-2006, 03:47 AM
#16
12 Second Club
Thread Starter
iTrader: (6)
Join Date: Jun 2004
Location: Ft. Irwin, California (But Virginia is home)
Posts: 1,501
Likes: 0
Received 7 Likes
on
1 Post
Originally Posted by CAT3
Actually it set a little richer than 11:1 since you dont have the 2-3 Bar MAP yet But if it makes you feel better to say Eleven to one sure
But if it makes you feel better to say Eleven to one sure 
Either way, it's set richer than it's actually running now.
06-21-2006, 09:53 AM
#17
TECH Addict
I am always suprised folks that venture into FI don't know this stuff.
Been running a boost referenced regulator for about 5 years now and I always tell anybody that goes FI to get one.
Oh and BTW the front mount regulator is I hear the superior way to install it, but for cost savings and ease of install you can install one out back by the T block where the fuel filter is, pretty easily done, and it works great.
Been running a boost referenced regulator for about 5 years now and I always tell anybody that goes FI to get one.
Oh and BTW the front mount regulator is I hear the superior way to install it, but for cost savings and ease of install you can install one out back by the T block where the fuel filter is, pretty easily done, and it works great.
06-21-2006, 10:57 AM
#18
Originally Posted by Blackbird
I
Oh and BTW the front mount regulator is I hear the superior way to install it, but for cost savings and ease of install you can install one out back by the T block where the fuel filter is, pretty easily done, and it works great.
Oh and BTW the front mount regulator is I hear the superior way to install it, but for cost savings and ease of install you can install one out back by the T block where the fuel filter is, pretty easily done, and it works great.
06-21-2006, 11:02 AM
#19
TECH Addict
PM me around 6pm pacific time tonite to jog my memory and I will go out and take pics.
As they say a picture is worth 1000 words. Plus I will need to go look at it again to jog my memory since it has been about 5 years now since I installed it
As they say a picture is worth 1000 words. Plus I will need to go look at it again to jog my memory since it has been about 5 years now since I installed it
