Hey guys I have a TB from a 454 and have noticed that there are 3 different injectors for them. Do they each require a different fuel pressure?? I did do a search but didn't see anything..
I am in the process of building a 383 for my truck and just need to know if a fuel pump is needed to keep everything happy.
Thanks

 

I would get a adjustable fuel pressure regulator.

 

i'd put a walboro 255 pump in jus to be safe . i've always had good luck with them .

 

Yes will require different fuel pressures and tune, as they provide different amounts of fuel @ equal pressure, scroll down http://dynamicefi.com/TBI_Fueling.php

Try typing the #on your injectors in the search function, should be some good imput.

 

TPI pump would be a better choice. Keep in mind, the return system is not conceived to flow huge amounts of fuel back to the fuel tank. And a walbro 255 @ only around 20 psi will flow a huge amount of fuel.

 

i don't know much about his trucks fuel system . i believe in overkill with a fuel system so i'd up grade the return lines then an run the bigger pump . better safe than sorry . just my opinion

 

The TPI pump is safe up to around 450hp.
ACD#241 TPI pump delievers 40 GPH = aprox 150 LPH. (PSI shutoff 65-75)
In theory that's good for 480hp, hp = flow rate (gph) * 12

Another nice internet formula.
HP divided by 2 = lbs./ hr
lbs./hr divided by 6 = GPH (minimum)
multiply GPH by 1.15 for safety.

 

Hey thanks for the help guys!!!!!! This will be almost a daily driver but more so to tow my race car in an enclosed 24" trailer and looking to get close to 400hp..
Trying to come up with a plan as it has a 4l60E trans as it's a 94 C2500 2wd and see from reading here it has a better puter in it than the early years.
Looking for about 9 to 1 compression with a forged dished piston and a factory roller cam from a caprice police car..
Any help at all is appreciated!!!

 

In this case make sure you do not have the 46 #/hr BB TBI injectors, they will never flow anough.

Exemple with 80 #/hr injectors @ 23 psi fuel pressure, would support 400 fwhp and require 35 GPH.

A police caprice cam sounds too mild to produce 400 fwhp in a 383. Were did you get that #?

 

Thomas,Just had a brain fade but looking for 300+ hp sorry. I have a BB tbi that has 17104288 injectors in it. So do you think those will support this kind of HP with having an adjustable regulator??
Thanks

 

17104288 injectors appear to be 94-95 7.4L TBI trucks (230-255 hp) 45lb/hr injectors.
https://www.thirdgen.org/forums/post...188-post2.html

For 300 fwhp I would use the 350 TBI 61-68 #/hr injectors, requires around 25 psi and VRFPR.

Or could try the 75 #/hr @ around 17 psi with AFPR.

 

Thanks Thomas, So your saying that the injectors with the BB TBI that I have will need different injectors..

 

The 45 #/hr injectors @ around 30 psi are ok for the 230-255 hp the BB produced.
But they would need to be run @ around 45 psi to support your 300 fwhp engine.
Personally I have no experience running these injectors with such high fuel pressure.

 

i'm pretty sure 30 psi max. on those injecters . 30 psi on 55 lb hr injecters should be enough for 316 fwhp . as calculater by my ebl utility . 61 lb hr injecters at 30 psi are good for 350 fwhp an 80 lb hr injecters are good for 459 fwhp at 30 psi ....

 

How do you come to that conclusion?

 

Thanks guys, Where can I get the part #s for 55 or 61lb injectors??

 

i'm pretty sure i read somewhere that 30 psi of fuel pressure is the max safe limit for tbi injecters .

 

Please do us a favor and post the link of the place, were you'r pretty sure you got that information from.

 

Did you try a search?

Exemple:
55 #/hr - GM5235279
80 #/hr - GM17084304
And these work @ over 30 psi too, if it needs to be.

 

i'm curious what your doubting ? do you think 30 is to high or to low ?
heres one where people are talking about running higher than 30 psi :
https://www.thirdgen.org/forums/tbi/...-pressure.html
i've read so much on these things can't quite place the link . my ol computer with all the saved links crashed . hopefully someone else will chime in on this tho . i'm sure up to 30 psi is safe after that i don't know
but i'm sure my calculations for the different injecters are correct since i used the ebl flash utility

 

Well that tread confirms that they can be run @ over 30 psi. I myself have run 35 psi.

I thought you may have some prof of someone having injector issues @ over 30 psi.

 

Thanks again, Where can one buy a set of injectors that are useable and not junk with out going to the dealer??

 

i'm gonna buy a 454 tbi off ebay ...

 

This is a tgo member http://tbiparts.com/
Or get a set anywere and have them tested http://www.witchhunter.com/

 

Thanks Thomas for those links!!