454 tbi high preasure oem injector, advice

[Greased-lightning]

Hello
just bought a 454 tbi for my 383 stroker 17104288 injectors.

Engine has big cam, procomp heads 200cc runners 64cc chambers, Holley air gap intake, Waldo 225 pump.

tbi has Been machined for more airflow.
"..."..............

found out those injectors are #40 at 13psi. And like #70 at 29psi. With my engine should I remove current injectors and install low preasure 454 injectors and turn them up to 30psi?
Or use current injectors and juice them up to 40psi??

[Roadknee]

I don't think you'll get enough out of the stock injectors at 40 psi. I'd try the low pressure injectors. Depending on your power level you might be able to get away with less pressure. For what its worth, I've run low pressure 5.7L injectors at 28 psi for a few thousand miles with no issues.

[Greased-lightning]

that's what I was thinking
i think I need atleast. 33psi the feed my engine on the #90 injectors
i got a Waldo gls392 pump that flows 45psi minimum do you think I will be ok with that?

[Roadknee]

The quick and dirty method to estimate the required injector size for a 2-injector TBI unit is to divide HP by four and add 10 percent. A 400 HP engine would need 110 lb/hr injectors, and they would operate at 90% duty cycle.

Pump gas weighs about 6.3 lbs per gallon. 220 lb/hr would be about 35 gal/hr or 132 liters per hour. A Walbro 255 LPH will provide nearly a 2:1 safety factor and should be fine.

[Greased-lightning]

Thanks for the information
i just bought #90 injectors
one last question anyone know where I can get a good base Bin file for my 383 ?

[Roadknee]

What ECM? Vehicle info?

[Nasty-Z]

Personally I would start out with the low pressure early 454 injectors , they are more stable at higher pressures than the 94-95 injectors.

The early injectors , if stock and not modified left GM at 80#/hr @ 13psi , there are no factory 90#/hr 454 TBI injectors no matter what anyone tells you , and that is straight from GM insiders.

TOM

[Fast355]

Personally I would start out with the low pressure early 454 injectors , they are more stable at higher pressures than the 94-95 injectors.

The early injectors , if stock and not modified left GM at 80#/hr @ 13psi , there are no factory 90#/hr 454 TBI injectors no matter what anyone tells you , and that is straight from GM insiders.

TOM

There are bigger injectors than 90 for TBI that came out of GM. Something in the neighborhood of 125 lb/hr. They were used on the single TBI alcohol fueled 4.1s in Central/South america.

[Nasty-Z]

There are bigger injectors than 90 for TBI that came out of GM. Something in the neighborhood of 125 lb/hr. They were used on the single TBI alcohol fueled 4.1s in Central/South america.

You know Chris , as I typed that I knew you would chime in with those examples ....... LOL . You were the one who put me on the mad dash to find these and a pod to use them in ........

But as you well know , they will not fit in the injector pod the OP is referring to, the factory 454 TBI injector pod , to use the injectors you reference you need the HD truck injector pod like this :

8592


So again I will say (with a modification) , there are no 90#/hr injectors (or any larger injectors) from GM for the 2" bore 454 TBI unit , they are all 80#/hr @ 13 psi . Period.

TOM

[fastacton]

There are bigger injectors than 90 for TBI that came out of GM. Something in the neighborhood of 125 lb/hr. They were used on the single TBI alcohol fueled 4.1s in Central/South america.

Do you have part numbers on these and the injector pod needed? Are they still readily available?

[Greased-lightning]

What ECM? Vehicle info?

Hello. Roadknee
ECM- 16197427 Bpsa 93-95 5.7 with 4l60e
i also have a 1995 454 tbi. Have a complete wiring harrness from a 95 suburban
orders the basic stuff from Moates to burn and log, also bought Tunerpro rt.

engine is a 383 stroker
procomp heads 200cc runners
Holley air gap intake
howards big hydraulic cam has a rough idle I'll have to look up the specs on my cam.
10-1 compression
It's sitting in a 1979 trans am