Help with FI fuel system
Thread Starter
TECH Apprentice
Joined: Feb 2005
Posts: 364
Likes: 0
From: Newark,DE
Help with FI fuel system I am putting together everything for the blower swap and wanted to get some opinions on weather or not this setup will be sufficient. The goal is 550rwhp. All parts are in my sig. The pump is a Walbro inline 255, Speed Inc fuel rails with there install kit. I am using the factory in-tank pump.
Do I need a regulator?
Do I need an additional filter?
What does the return type fuel system do for you? Factory is not like this right? Do I need this?
Fuel system currently is 100% stock.
Any help you guys can provide would be greatly appriciated. Assume I know nothing when answering this post because when it come to fueling I DON'T. I want to do this install next weekend and want to have everything in hand before I attempt this. I have tried searching and did not get anything useful.
Thanks,
Dave
Do I need a regulator?
Do I need an additional filter?
What does the return type fuel system do for you? Factory is not like this right? Do I need this?
Fuel system currently is 100% stock.
Any help you guys can provide would be greatly appriciated. Assume I know nothing when answering this post because when it come to fueling I DON'T. I want to do this install next weekend and want to have everything in hand before I attempt this. I have tried searching and did not get anything useful.
Thanks,
Dave
Get a Racetronix in tank kit from Harris, Nate, Thunder, etc at the right. An inline pump will not work properly with a +1999 year system that uses a siphon. At 550rwhp I'd keep the factory regulator, lines etc .
The problem is the +1999 factory system needs a pressure head for the siphon to fill the factory bucket where the pump is located. If you install an inline it lessens the pressure head and the bucket doesn't fill properly, potentially causing the pump to cavitate...the LAST thing you need with a blower. Harris Speed Works an set you up with a Racetronix system...cheap insurance.
Originally Posted by LastBlack02SS
Confused. So would you run into the problem if you ran a larger in tank as well as adding an inline pump?
Im not sure about LS1's but an LT1 cars factory fuel lines and fittings will not flow the lbs/hr of fuel your injectors will be able to flow... In other words, do all you want to increase head(pump supply) you cant pass enough fuel through the lines.
Like I said, Im not positive about the LS1 lines though. If you go to Aeroquips website and search around, theres a formula for figuring how much fuel a given line diameter is capable of flowing.
Then depending on the HP level you want your fuel system to flow up to, you need to figure the pump and line sizes accordingly...
One thing I can tell you, definitely dont run two pumps one after another and a single Walbro wont flow the required fuel.
I'll use my system as an example:
60# injectors with base FP @ 43.5psi
1:1 boost ref. regulator brings fuel pressure to 58.5psi at 15psig boost.
60# injectors will flow right around 75lb-hr @58psi
75lb*8 = 600lb/hr or 100gal/hr required flow
Fuel pump flow drops as pressure increases, so for this app two Walbro inlines plumbed in parallel will just barely support flow with hotwire providing 13volts. All together, my fuel system should support 800 flywheel HP on pump gas at a figured .06 bsfc.
My calculations said that I needed an -8an feed line to flow that much gas at that much pressure.
If I were able to run low impedance injectors at lower FP, I could have gotten away with a single aeromotive A-1000. Due to increased FP the aeromotive wont flow what I need.
Hope that helps
Like I said, Im not positive about the LS1 lines though. If you go to Aeroquips website and search around, theres a formula for figuring how much fuel a given line diameter is capable of flowing.
Then depending on the HP level you want your fuel system to flow up to, you need to figure the pump and line sizes accordingly...
One thing I can tell you, definitely dont run two pumps one after another and a single Walbro wont flow the required fuel.
I'll use my system as an example:
60# injectors with base FP @ 43.5psi
1:1 boost ref. regulator brings fuel pressure to 58.5psi at 15psig boost.
60# injectors will flow right around 75lb-hr @58psi
75lb*8 = 600lb/hr or 100gal/hr required flow
Fuel pump flow drops as pressure increases, so for this app two Walbro inlines plumbed in parallel will just barely support flow with hotwire providing 13volts. All together, my fuel system should support 800 flywheel HP on pump gas at a figured .06 bsfc.
My calculations said that I needed an -8an feed line to flow that much gas at that much pressure.
If I were able to run low impedance injectors at lower FP, I could have gotten away with a single aeromotive A-1000. Due to increased FP the aeromotive wont flow what I need.
Hope that helps
Trending Topics
Run one Walbro in the tank forget the inline pump it will not help your situation. Leaving the rest of the system stock will work for your 550rwhp but any more you are going to have to upgrade the rest of the system.
Nate
Nate
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
TECH Apprentice
Joined: Feb 2005
Posts: 364
Likes: 0
From: Newark,DE
Originally Posted by Nasty N8
Run one Walbro in the tank forget the inline pump it will not help your situation. Leaving the rest of the system stock will work for your 550rwhp but any more you are going to have to upgrade the rest of the system.
Nate
Nate
Nate,
I went ahead and got the racetronix kit and set it up. The car pulled 541rwhp but showed it started to lean out above 5500. The more I drove the car the worse it got I ended up close to 14.1 under boost at 6200. I thought I saw about 44ps1 on the fuel gauge.
The car at this point had 1/2 tank of fuel started with a full tank at the dyno. So no more betting it until I figured it out. Next day I drove it again and progressively took the rpm higher making sure with each pass AFR stayed in the low 11's. All was good and never got higher then 12.0 AFR and the fuel pressure never dropped below 52psi.So my questions is this. Do most people punch holes in the factory bucket?
Could I be sucking the bucket dry? I just replaced the factory pump, bolt for bolt wire for wire. Is there something I am missing with the pump install?
Please help I have not heard back from Racetronix yet.
Dave
Dave
Thread Starter
TECH Apprentice
Joined: Feb 2005
Posts: 364
Likes: 0
From: Newark,DE
oh yeah, all hooked up. Is 52psi to much of a drop? is it possible that my factory fuel filter is restrictive? Where is the factory fuel regulator, in-tank? Do most people get rid of the siphon and put holes in the bucket.
52 is a little low, but wit the AF at 12.0 max you are safe as the AF rules not psi. Regulator is in the tank. Don't put holes in the bucket, kills the baffleing effect. If the AF is stable, enjoy the ride.