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View Full Version : How to figure what size fuel injector size to run.


Boomer!
09-03-2006, 10:33 AM
A simple forumla which is very accurate. I always here people say what size should i run.



[ estimated rwhp X .50 ) / 8] /.8 = injector size.

say you have estimated 400 x .50 = 200 divided 8 which is the number of injectors on the engine= 25 divided by .8 which is the injector duty cycle= 31.25 < being the smallest suggested injector size to run.

When selecting a injector round the number up to the next available size as it is better to be below 80% duty than above. Blown or turbo application should figure for 70% duty cycle.

N/a and nitrous V8 reference chart
__________________________________________________ ______
hp injector size #'s

250 19.53
300 23.43
350 27.34
400 31.25
450 35.16
500 39.06
550 42.97
600 46.88

speedy
01-07-2007, 07:32 PM
I have this info on the subject. It's out of Hot Rod mag.