Fuel Injector Size Recommendations

[Shane_713]

Considering Nitrous injection for the following mods: GT40P heads, Trick Flow stage 1 cam, and Edelbrock Performer intake plus all associated bolt-on's (long tube headers, off-road H-pipe, cat-back exhaust, under drive pulleys, coil, distributor module, etc. etc. you get the idea). Will 24# injectors and 75mm mass air suffice for 100 shot (dry), or 150 shot (wet) nitrous systems? Looking for 375HP at the wheels; and your suggestions. Thanks.

 

[jrichker]

Injector HP ratings: divide flow rating by.5 and multiply the result by the number of injectors. This uses a 100% duty cycle. These ratings are for naturally aspirated engines. See my comments on pressurized induction in the paragraphs following this one.
Example:
19/.5 = 38, 38 x 8 = 304
24/.5 = 48, 48 x 8 = 384
30/.5 = 60, 60 x 8 = 480

The preferred duty cycle is about 85% maximum, so for a safety factor mulitply the final figure times .85.

Remember that the above ratings are at 39 PSI. Increasing the pressure will effectively increase the flow rating. Example: a 19 lb injector will flow 24 lbs at 63 PSI, and a 24 lb injector will flow 30 lbs at 63 PSI.

 

[Grn92LX]

30's if you do a dry kit and 24's if you do wet. I would just do 30's either way incase you upgrade your n/a combo down the road.

Use a 255 high press pump for the dry kit and a std 255 if you do wet.

 

[Shane_713]

thanks for the suggestions.

 

[2002BLGT]

19s will be fine with a wet kit , put a good fuel pump in the car and use a wet kit , stock timing , 1 range lower heat range plug and a 65 nitrous and 36 fuel jet , should dyno about 360 rwhp and 500 rwtq almost identical to a friends setup