fuel pressure on ls-t b18b
 

First thread ever so bear with me....i need to know what i should set my bm afpr to im running a ls with a newly installed t3/t4 turbo havent even tried to start it yet...

jdm ls b18 (same tranny)
exedy oem clutch 7lb flywheel
walbro 255
bm afpr
dsm 450cc injectors
t3/t4 turbo

just need to know what i should set the regualtor to before i try n start this thing new cold plugs are already in ngk bkr7e final touch is setting the correct fuel runnning reg 93...anything would help thanks guys

Re: fuel pressure on ls-t b18b
 

leave the fp at stock, what are you using for tuning?

Re: fuel pressure on ls-t b18b
 

And I dont see that clutch lasting very long

Re: fuel pressure on ls-t b18b
 

If all you did was install the turbo. Leave it stock at 44 I think. And stay out of boost till you get it tuned once its tuned don't touch it again.

Re: fuel pressure on ls-t b18b
 

I agree. Leave the fuel pressure where it is stock. If you need more fuel, your tuner can make adjustments while it's there on the dyno and has the equipment to monitor what the engine is doing/needing.

Re: fuel pressure on ls-t b18b
 

hopefully clutch will last its only got about 3k on it im not going to beat it to bad i only plan on running the wastegate spring..8psi i think and its a crome tune i believe whatever phearable put in it..ok well ive got the gauge on there so ill watch it when i turn it on..tune may be a little while away hoping it runs decent on map for a few weeks

Re: fuel pressure on ls-t b18b
 

You should at least street tune it. It cost about 150-180. Its better than no tune. Your motor can lean out very easily and blow.

Re: fuel pressure on ls-t b18b
 

yea i plan on dyno tuning it in buffalo in a couple of weeks im going to turn the fp up to 55 from the stock 44 to prevent any leaning on in the time being

Re: fuel pressure on ls-t b18b
 

stock fpr

Re: fuel pressure on ls-t b18b
 

i am a noob on this forum but i mstill disagreeing with some of this such as a stock fpr that would mean 44psi which yes will lean the motor out and fry shit i turned my bm up to 54 and the cars runs beautifully on a phearable chip no smoking no gas smell and i know its getting the gas it needs running great on 8lbs =)

Re: fuel pressure on ls-t b18b
 

Well, yeah. You can't just go playing with fuel pressures without having a way to adjust the fuel delivery and monitor the changes. The reason to turn up the fuel pressure is to provide more fuel or compensate for more boost pressure. If you are running 450cc injectors @ stock fuel pressure, you should have enough fuel for ~250-275whp.

The reason it's running well, the chip is probably programmed for it...but I would imagine it would run just as well at the stock fuel pressure if it was tuned for it.

Re: fuel pressure on ls-t b18b
 

I am running 60psi on my LS-T. Walbro 255 and stock lines/rail RC 440cc. Its all mainly a preference. Higher pressure will be able to maintain proper atomization under higher boost pressures. Think about it... If you run 20psi of boost through intake manifold and you only have 44PSI of fuel pressure, those forces are fighting against each other. The positive pressure wants to push the fuel back through the rail and into the gas tank. THAT is the main reason for running higher fuel pressure, contrary to the belief that its just to get more fuel out of your XXXcc injectors. How much boost do you plan on running?

Keep in mind that if you ever change your fuel pressure, you will need to retune the entire fuel table.

Re: fuel pressure on ls-t b18b
 

Really depends on the injectors size and style along with fuel pump flow capabilities and what kind of boost your running. there is no one answer for the question. And if it needs to be tuned then your tuner should have a base fuel pressure they like to start with and go from there. I generally start with a 50 base static fuel pressure on say a walbro 255 standar pump and that will give you room for about 20 psi boost before the pump can no longer keep up. if your running a better pump that is capable of higher pressures liek a bosch 044 of walbro 255hp then you wil be able ot get more base pressure and boost pressure out of it

Re: fuel pressure on ls-t b18b
 

Right, and if you are running a 1:1 FPR, the regulator will allow you to maintain the stock fuel pressure differential. 44psi base fuel pressure + 20lbs boost + 1:1 FPR = 64psi fuel pressure. +/-

Re: fuel pressure on ls-t b18b
 

unless you have a wideband o2 sensor then you dont "know" anything about what fuel the car is getting. unfortunately your nose is not a precision instrument. the chip that phearable sent is just a basemap not a precise tune. boosting on unknown fuel and timing values is a good way to ruin your motor.

you dont need an adjustable fpr with your setup. stock fuel pressure is fine, let the tuning program increase the fuel deliverly.

Re: fuel pressure on ls-t b18b
 

ok I put a B18a in my 89 Crx si and I really need to no the right fuel pressure for my car cuz it keeps brakeing my rear motor mount cuz when I'm drive it cuts out on me really bad one more? ok my si Crx will not go past 5500 rpm and I have my timeing right and I'm really with it all so if you can help me can you text me pls 570-604-8049 and you can hit me up on facebook me name on there is mon-e Fischer and my email is simoney91@Hotmail.com

Re: fuel pressure on ls-t b18b
 

^ Troll? lmao

Re: fuel pressure on ls-t b18b
 

this is well said and accurate, plus that basemap probably has its fuel values set with stock pressure in mind (43psi at idle with the vacuum line disconnected from the regulator and plugged so its not a massive vacuum leak) you can adjust the fuel right through the laptop which is great. my car made 475whp on 880cc injectors and stock fp, you will be just fine with stock fp. also, there is no way i would drive a turbo car without a wideband.

Re: fuel pressure on ls-t b18b
 

But why bump it?