jchevy

I am building a turbo setup, wont be running more than 15 psi and am hoping to make in the 550 rwhp range. What do I need to do with my fuel system. What injectors are you guys running, what about an adjustable fuel pressure regulator? I have a walbro 340 in tank pump now. Is that big enough?

I am trying to figure out what injectors I need. I read that at 58 psi fuel pressure the ford 42# injecotors will flow 50#.

Is this ok to do? Tunning isssues when doing this, like at idle?

subarubill96

hey man,
i answered this question for you over in part in your other thread in case you didnt see. i would stick with stock fuel pressure, the tuning and potential detonation issues can suck when changing fuel pressure to make up for undersized injectors. your gonna be sucking alot of air at 15 pounds of boost so like i mentioned in the other thread go with AT LEAST 60 lb injectors, your gonna max those 42's out at that horsepower level. you can now run up to 79lb injectors without having to go low impedance which should be more than enough in cause you get the itch to up the boost later. what size turbo you gonna run? front mount, rear mount?

jchevy

Yeah, I saw your other post and that got me searching. In my searches I saw that a 42# injector in a ford is actually a 50# injector in an LS1 b/c of the fuel pressure difference. I also noticed some other posts where people run an extra pound of fuel pressure per pound of boost. Im just trying to figure out what I can and cant do.

subarubill96

this is for an LT1 right? dont wanna give you all funky info then find out its for an LS1 lol the stock fuel pressure for an LT1 is 43.5 +/- .5lb now they do make FMU's (fuel management unit) which will raise your fuel pressure per pound of boost depending on the ratio you set it at. you dont wanna use a FMU imho, they are unreliable and it just takes not working once to blow your motor. (ask me how i know ) they also make fuel regulators that will increase fuel pressure per lb of boost. but if 550 is your goal, your really pushing those 42's better off to be safe and go 60's. more info on your setup would help get a better picture of what you will need. im planning a similiar build for my 95 camaro. forged 383 w turbonetics t76 pushing like 550rwhp around 12-15 lbs

jchevy

Yes LT1

Its a t4/t67 garrett turbo. Its going to be a 355 in the neighborhood of 8.5:1 compressioin. LE1 heads and havent decided on a cam yet.


Seems like with a 383 and a t-76 you should be higher than 550 rwhp. Am I setting my sights to high for this t67?

subarubill96

ahah i should mention i overkill everything i do. build it for 1000hp and you will have a strong basis for 500. my whole setup is about being adjustable for my use. will your 67 make 550rwhp on a 355 8.5 compression motor, i would say its very possible with good supporting mods. the 76 will do it with alot less effort and considering its the same price for either one im going 76. would i have any qualms about using a t67? hell no, but when 550 isnt enough, ill be kicking myself for not getting the 76. then when i max that out, the t88 lol it never ends...

RealQuick

You'll crush that with good heads... probably 600-625rwhp @ 12psi.

subarubill96

ahaha yea if i dont crush the built 4l60e i plan on using first, its easy to build the motor to handle the hard part is having everything else not give up the ghost, cant wait to find that weak leak but its probably gonna be the tranny

Boosted_Z28

Regardless of your set-up, you will definately need to run a boost sensitive adjustable fuel pressure regulator. You will need to make up for that 15 lbs. of pressure that will be in the intake tract when in boost by raising the fuel pressure accordingly. If not, you will have cut your fuel pressure by 1/3 and the motor won't like it.

subarubill96

yea i did mention the boost sensitive regulator but since we were focusing more on the injectors i was leaving it out of the equation to make it a little easier to understand for the OP but good point on bringing it up

jchevy

Wow, so I am completely lost. Lets say I have 60# injectors. What regulator do i need? So not in boost fuel pressure would be stock, but as it sees boost it increases the pressure?

subarubill96

ahaha i was trying to keep it as simple as possible.say you have stock fuel pressure (43.5lbs), add 13.5 psi boost = 30 (happy jon?) lbs of fuel pressure due to fighting 13.5s of boost so the boost sensitive regulator will add pressure to make up so even at 13.5 psi you are seeing the full stock pressure with this regulator at full boost it also allows you to be at 43.5 at idle as its only seeing vacuum. that help any?

jchevy

Yup. Makes sense! What are they called so I can start pring them, I was looking in summit and didnt really see anything like that.

Thanks for all the help

Boosted_Z28

Try this:

http://store.summitracing.com/partde...5&autoview=sku

subarubill96

boosted beat me to it. check out nasty performance, they are a supporting vendor on ls1tech for complete fuel systems for your lt1 as you can also use a KB boost a pump which is boost sensitive. many ways to skin a cat lol