F.I. fuel pressure theories

[Stan Weiss]

Originally Posted by Pierce Jones

I'm new to FI, only self taught and going on 3 seasons. I just got back from the chassis dyno. Engine is an LT1 with Holley HP. Running 24 lbs/hr @ 70 psi, log shows 7.99 msec, 90% duty @ 7000RPM. Chassis dyno showed 415hp ish

Stan - Maybe Holley calculates duty cycle on 360degrees?

Unfortunately I didn't have a larger set of injectors to throw in and try.

My biggest issues continue to be hot start and idle quality, decided to try and sort that out at home instead of on the dyno.

I started playing with the Injector End Angle (IEA) Table for the first time. Very slick in V5, essentlially plug in cam specs and it calculates IEA based on fuel table. My set-up uses the crank tigger only.

Pierce,
I have never used the Holley system and so do not know how it works.


Maybe Rob from Holley will see this thread and explain it.


Based on my understanding of what you have, and running some numbers I believe the 90% is correct. I believe the 7.99 msec (what should be the pulse width) is not correct.


Stan