Fuel Pressure?
Thread Starter
Melting Slicks
Joined: Jul 2007
Posts: 2,939
Likes: 7
From: Simpsonville SC
St. Jude Donor '09-'10
Fuel Pressure?
How much fuel pressure is optimum for:
With my new fuel system, I have it set to regulate 60 PSI while idling. I have a boost refereced pressure regulator, so as boost increases, so does the fuel pressure. When I am doing normal driving, I see around 65 PSI. When I go WOT, My fuel pressure goes up to about 75 PSI.
Is 75 too high? Is 65 too high for crusing? I know my MPG has really gone down since installing my new fuel system!
How low can it be set and run well?
- Normal driving
- Boost
With my new fuel system, I have it set to regulate 60 PSI while idling. I have a boost refereced pressure regulator, so as boost increases, so does the fuel pressure. When I am doing normal driving, I see around 65 PSI. When I go WOT, My fuel pressure goes up to about 75 PSI.
Is 75 too high? Is 65 too high for crusing? I know my MPG has really gone down since installing my new fuel system!
How low can it be set and run well?
Former Vendor
Joined: Oct 2004
Posts: 2,592
Likes: 0
From: FI Performance : Norwalk Connecticut www.FIPERFORMANCE.com
We need some additional info in order to give you the correct info so please lay down your entire setup.
Brian
Brian
How much fuel pressure is optimum for:
With my new fuel system, I have it set to regulate 60 PSI while idling. I have a boost refereced pressure regulator, so as boost increases, so does the fuel pressure. When I am doing normal driving, I see around 65 PSI. When I go WOT, My fuel pressure goes up to about 75 PSI.
Is 75 too high? Is 65 too high for crusing? I know my MPG has really gone down since installing my new fuel system!
How low can it be set and run well?
- Normal driving
- Boost
With my new fuel system, I have it set to regulate 60 PSI while idling. I have a boost refereced pressure regulator, so as boost increases, so does the fuel pressure. When I am doing normal driving, I see around 65 PSI. When I go WOT, My fuel pressure goes up to about 75 PSI.
Is 75 too high? Is 65 too high for crusing? I know my MPG has really gone down since installing my new fuel system!
How low can it be set and run well?
Thread Starter
Melting Slicks
Joined: Jul 2007
Posts: 2,939
Likes: 7
From: Simpsonville SC
St. Jude Donor '09-'10
Please check out my Major Driveline update thread for all the info you want!
http://forums.corvetteforum.com/c5-t...-new-post.html
http://forums.corvetteforum.com/c5-t...-new-post.html
Former Vendor
Joined: Oct 2004
Posts: 2,592
Likes: 0
From: FI Performance : Norwalk Connecticut www.FIPERFORMANCE.com
That is a hell of a setup and unless i missed it, I didn't see info on the following:
Boost pressure up top
Air/fuel ratio?
What kind of tune and where is your timing at? SD or Maf tune? Most of the time we see 60 on average when cruising. I know on my 9 psi D1, I see 60 at cruise however when i load up, it will sometimes drop to 52-55 yet my AF's are exactly where they should be. I dont have an agressive fuel setup, GSS342 in the tank and a bap with custom fuel rails with straight cross over line eliminating the OEM FPR. SO when I hit 3-5 psi the bap kicks in.
Brian
Boost pressure up top
Air/fuel ratio?
What kind of tune and where is your timing at? SD or Maf tune? Most of the time we see 60 on average when cruising. I know on my 9 psi D1, I see 60 at cruise however when i load up, it will sometimes drop to 52-55 yet my AF's are exactly where they should be. I dont have an agressive fuel setup, GSS342 in the tank and a bap with custom fuel rails with straight cross over line eliminating the OEM FPR. SO when I hit 3-5 psi the bap kicks in.
Brian
Thread Starter
Melting Slicks
Joined: Jul 2007
Posts: 2,939
Likes: 7
From: Simpsonville SC
St. Jude Donor '09-'10
My AF is working great. Normal crusing, i see it hovering around 14.7. Under boost, it drops down to around 11.0. I am using a MAF still. It is a 100MM MAF.
When I had my original fuel pump and lines with a BAP, My pressure was around 55, but would drop to around 45 under load. Thats why I replaced my entire fuel system with what I have now.
I am just thinking I may have TOO MUCH pressure under boost now!
When I had my original fuel pump and lines with a BAP, My pressure was around 55, but would drop to around 45 under load. Thats why I replaced my entire fuel system with what I have now.
I am just thinking I may have TOO MUCH pressure under boost now!
Race Director
Joined: Apr 2009
Posts: 10,581
Likes: 252
From: SE TEX
I have a boost referenced system as well. My tuner set my idle for 55psi and so far in boost (with belt slip) I have seen about 8# and 71 psi fuel. Even in max vacuum I have only seen the fuel drop to around 51 psi.
Did you retune for the change in FP?
Did you retune for the change in FP?
Race Director
Joined: Apr 2009
Posts: 10,581
Likes: 252
From: SE TEX
You're car is probably running rich with the extra fuel pressure. Stock pressure was around 57-58, not sure though if that's what you were tuned for originally. Break her all in and then get that puppy tuned, should get you back on track 
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Instructor
Joined: Feb 2009
Posts: 205
Likes: 2
From: buffalo center iowa
MIne stays at 59lbs all the time. aux system comes on at 3 lbs. I don't have a wideband but the afr is 11.5 without meth, but I have meth and it is way to fat when it sprays cause it really lays down over 5700 rpm. I am supposed to bet getting a dyno sheet from them but haven't gotten it inthe mail yet.
Former Vendor
Joined: Oct 2004
Posts: 2,592
Likes: 0
From: FI Performance : Norwalk Connecticut www.FIPERFORMANCE.com
Everything right now points to adjustments, at least your AF's are good for break-in, don't mind the $$$ signs coming out of the tail pipes.
Brian
Thread Starter
Melting Slicks
Joined: Jul 2007
Posts: 2,939
Likes: 7
From: Simpsonville SC
St. Jude Donor '09-'10
Well, since my MPG went from 21 down to 13, I feel it must be running too rich for my taste! Well, it really is just making my exhaust tips black quickly.
