I don't understand how these fuel injectors work, I see guys with 42lb injectors with 400hp and I see people with much smaller injectors making just as big of numbers.

I thought injectors were like carb cfm...

I'm looking at some 42lb injectors, but I am afraid they will be too big for my application (blown 350)

How about tuning? how much of an issue is tuning with larger injectors?

 

Well, first thing u need to do is you basic math to determine your injector needs. I dont have it off the top of my head but on turbo/super engines, basically use a bsfc of .55.

42# wouldnt be absurd at all on a 350 with 12-15psi of boost, depending on the overall package.

Somethings to note when changing injectors.

Chip burning will be mandatory, u will have to accomodate the Injector Constant for the larger injectors as well as haveing to play with AE and some other stuff. Again alot depends on the whole package and how you end up doing it ie, intercooled or not, run a factory boost sensing ecm like the 749(highly rec) or using an FMU(not the best way)

Hit the Prom board for alot more info about injector sizing and what to look for as well as real solution to running boost reliably using factory ecm's, not band aids like fmu's and retard boxes.

later
Jeremy

 

[QUOTE]Originally posted by 3.8TransAM
[B]Well, first thing u need to do is you basic math to determine your injector needs. I dont have it off the top of my head but on turbo/super engines, basically use a bsfc of .55.


Horsepower X BSFC
---------------------------
# of injectors X 0.8

This should get you in the ballpark.