Will 36lb/hr injectors be enough?

[TweekedGT]

My KB kit comes with 36# injectors. will these be enough to support 450-500rwhp? I was told to get 55#ers but do I really need them? Can I get away with the 36's at the power leverl I want?

 

[tomustang]

55's should support 650hp

you should look into 42's

 

[Lons2001GT]

55's should support 650hp

you should look into 42's

I agree completely.

 

[Josh-'96 GT]

Does the KB use an FMU? If not and you're running ~43# of fuel pressure, 36# injectors are way too small.

To make 500 RWHP, you'll need to make about 590 FWHP assuming 15% drivetrain loss. Using a BSFC of .55 and a max duty cycle of 80%, it looks like you'll need around 50#/hr injectors to reach your goal.

Of course, if you have an FMU and are running higher fuel pressure, you'll have to re-run those numbers...

 

[TweekedGT]

Does the KB use an FMU? If not and you're running ~43# of fuel pressure, 36# injectors are way too small.

To make 500 RWHP, you'll need to make about 590 FWHP assuming 15% drivetrain loss. Using a BSFC of .55 and a max duty cycle of 80%, it looks like you'll need around 50#/hr injectors to reach your goal.

Of course, if you have an FMU and are running higher fuel pressure, you'll have to re-run those numbers...

If by FMU you mean fuel management unit I believe I do have one. It is in the kit as well, it's Kenne Bell's boost a pump which will help increase the fuel pressure.

 

[ooraceredgt]

42's

 

[Josh-'96 GT]

If by FMU you mean fuel management unit I believe I do have one. It is in the kit as well, it's Kenne Bell's boost a pump which will help increase the fuel pressure.

I expected as much...36# injectors seemed small. What boost level do you anticipate running to achieve the power levels you wanted? What boost to fuel pressure increase ratio does the KB FMU give you? Once you had those numbers you could rerun the formula...

...it'll probably come out to 42's...

 

[jstreet0204]

I expected as much...36# injectors seemed small. What boost level do you anticipate running to achieve the power levels you wanted? What boost to fuel pressure increase ratio does the KB FMU give you? Once you had those numbers you could rerun the formula...

...it'll probably come out to 42's...

KB doesn't use an FMU it comes with a chip. The chip has no boost references. Instead it increases fp based on ACT. The BAP does have a boost reference that will incease voltage to the pump based on boost, but I think it is linear, meaning it increases to a set voltage after it reads something like 3lbs of boost.

Here are the numbers they use.
ACT: 150 160 180 200
FP: 45 55 60 70