What would be the max hp of a 42# injector on a lt1 in a supercharged application? Would they be suitable in a 500 rwhp application? Thanks

 

Won't work.

You can't size the injector based on "rwhp".... you have to know the flywheel HP. Then you need to know the brake specific fuel comsumption (BSFC) of the engine, which is affected by the combustion chamber configuration and the quality of the tune. Then you have to determine how close to 100% duty cycle you want the injectors to run. A lot of assumptions, but.....

Assuming 500 rwHP through an automatic would put you at about 600 flywheel HP.

For BSFC, FI engines may run as high as 0.60 #/HR/HP. That means you need to supply 360 #/HR of fuel, through 8 injectors, or 45.0 #/HR per injector.

Assume you want to limit the injectors to 85% DC, and you need at least a 52.9 #/HR injector.

That's based on a lot of assumptions.

If you could achieve a BSFC of 0.55 #/HR/HP, you would be running the injectors at 98% DC. You don't want to do that.

Alternatively, you could run the injectors at a higher pressure. Running 58psi (assuming your 42's were flow rated at 43.5psi) would allow them to flow 48.5 #/HR.

 

im running 430rwhp on 42lb, non supercharged and my duty cycle is really low. I was told i could run a good power adder, and still have plenty of duty cycle left.

 

The BSFC for an NA engine is significantly lower than a supercharged engine. You could be running as low 65-70% DC on an 0.44 BSFC (again, based on a lot of assumptions) with your setup. That has no relavence to an FI application.