Accel 24# injectors work?

[XfireZ51]

Originally Posted by tpepmeie

That's not the way I would do it. I would instead modify the Secondary Inj PW scalar. Simplistically, if you are running 24 lb secondary, and 21 lb primaries, the correct value would be (21 / (21+24)) = .47.

Todd,

I’m going to make this point for the purpose of helping educate others here. Your suggestion of changing the Secondary Injector Scalar (which may be a misnomer) is simply to get the same “effective” PW as u would using two 21# injectors. Am I correct?
I’ll bet you will still need to visit the VE tables.
Second question, would that not negate the purpose of the 24# injectors in supplying fuel to a larger displacement motor?
BTW, I say the Secondary Injector Scalar is somewhat of a misnomer because the ECM does not drive the secondary injectors. The primary injectors signal the secondarys in terms of PW while the ECM simply energizes the secondary injectors thru the secondary relays.

[tpepmeie]

Originally Posted by XfireZ51

Todd,

I’m going to make this point for the purpose of helping educate others here. Your suggestion of changing the Secondary Injector Scalar (which may be a misnomer) is simply to get the same “effective” PW as u would using two 21# injectors. Am I correct?

Yes, same fuel mass delivered per injection event.

Originally Posted by XfireZ51

Second question, would that not negate the purpose of the 24# injectors in supplying fuel to a larger displacement motor?

Well, you would have more headroom before the secondary injectors are static, but by that time the primaries would be static, so what's the point? What I was trying to articulate is that it is completely feasible to run mixed injectors without a major tear up to the calibration. If somebody happens to have a set of secondaries which are larger, then very easy to calibrate--1 byte!

Originally Posted by XfireZ51

BTW, I say the Secondary Injector Scalar is somewhat of a misnomer because the ECM does not drive the secondary injectors. The primary injectors signal the secondarys in terms of PW while the ECM simply energizes the secondary injectors thru the secondary relays.

The correct label for that constant is technically "secondary injector ON pulsewidth scalar" In other words, its a scalar which gets applied anytime the secondary injectors are ON (via the ECM activation of the secondary relays).

[XfireZ51]

Thank you for the clarification. I hope it helps others following this. Cheers.