Is anyone using LS1 injectors on a TPI? Ive got a friend that just upgraded to a set of 60#'ers and he said i could have the stock ones. Im wondering how well they work and if i would have any problems with them?

 

60# FUEL INJECTORS on a TPI????? Recheck your info.

 

His friend bought larger injectors, probably for his FI LS1 engine and he wants to use the stock'er 26 or 28 lb LS1 injectors.

The answer is yes you can. I just finished up a customers IROC, forged bottom end with HSR intake and used a set of cleaned LS1 injectors I had laying around. You just need to play with the injector constant because you will be running them at much less pressure than the LS1 cars did

 

yeah the 60# set is going into his turbo LS1, the stock set hes giving me are 28#'ers.

jnjspd - I have no idea what you mean by playing with the injector constant. What will i have to do? is it something thats hard to get right? will they just plug in or am i going to have to change other things?

 

They will plug in an work, however if you don't have a custom PROM you will be spraying the larger injectors like you stock ones. Which might be too much fuel down low. You can play with fuel pressure, however that might leave you lean on the topend. That is where a custom PROM comes in handy

 

Theres nothing complicated about adjusting the injector constant in your PROM. Its just a number equivalent to the lb/hr your injectors are rated at. The only problem is getting the right equipment to access and reprogram your PROM.

 

I don't see how you can compensate for a 2-3 lb injector size difference with fuel pressure. There are atleast two different sized LS1 injectors, so doublecheck the size. Assuming they are the 28 lbers, I think they will be between 25 and 26 lbs at 43.5 psi, so your injector size in your prom should be set to that.

 

Your 22#/hr stock injectors probably supply you with enough fuel because you have an AFPR.

I read your sig, I dont see anything too far out that would require you to install larger injectors.

BTW: What year is your buddy's LS1 car?
'98s got 28s,,, '99 & '00 got 26s,,, '01s got ???, '02s got 28s.

And remember that the LS1 cars run 4 bars (58psi) for fuel pressure, while the 3rd gen cars run at 3 bars (43.5psi)...

The fuel injector constant is a value programmed into the Eprom chip. You have to know how to re-program chips to changed this value.

If you have no drivibility issues or idle issues,,, and need only more fuel at WOT for a good AFR, then simply turn up your fuel pressure. The learning process (BLM values) while at idle and cruising around will correct the fuel delivery,,, the learning process will not effect the fuel at WOT, in this mode, the ECM is in Power Enrichment (PE mode) and all BLM are changed to 128 which is baseline.

 

yeah i know i dont have anything real radical yet, but durring the christmas break ill be installing basically an LT4 hot cam, but its got a 109 centerline, and doing alot of head work. So i just figured if i can pick them up for free they cant hurt.

His car is a 98, but i dont understand the 3 bar, 4 bar thing.

and i found a guy in town that knows what hes doing and is going to burn me a chip when im ready for it

 

At a static pressure of 43.5psi an injector will flow at whatever it's rated.
a 28lber will flow 28lb/hr. To get it down to 22lb/hr the static pressure would have to be lowered to 27psi, but now the pressure is to low for the spray pattern to remain stable.
If the engine is designed to produce 400 bhp then 28 lb/hr injectors at a static pressure of 43.5 psi, and the ECM programed for that flow is what you need.
At 300 bhp engine needs 22lber.

 

Your buddies LS1 injectors flow 28.8 #/hr at 58psi fuel pressure. If you install those injectors into your TPI car which runs at 43.5psi fuel pressure, you will have the injectors flowing at 24.9 #/hr. So, get a Eprom chip "burned" for 24.9 #/hr in the constants table.

More:
LS1 cars run at a fuel pressure of 58psi (4 bars of pressure) from the factory. So, when people quote the flow rate of LS1 injectors, it is assumed that the flow rate is for 58 psi fuel pressure.
Now, our TPI 3rd gen cars run at a stock fuel pressure of 43.5psi (3 bars of pressure) from the factory. So, when people quote flow rates of 3rd gen EFI cars, it is assume that the flow rate is for when the fuel pressure is 43.5 psi.

BTW: 1 bar is 14.5 psi is one stardard atmosphere

 

ok that makes alot more sense, thanks!