Secondary Injector upgrade on S4 NA
 

I don't see much online about people upgrading their secondary fuel injectors on their NA rotary's, is there much point? I was thinking of trying some TII 550cc injectors in the secondaries on my S4 for the hell of it. I have a header and no cats, and I am planning on porting my intake, however I am running the stock ECU, so I don't know if it will do anything. I guess the worst that can happen is it will loose power and run way too rich lol.

unless you run a turbo there is no point.

Stock computer runs too rich for best power as it is, you'd be making a bad situation worse.

It runs that rich to SAVE the cat, oddly enough.

the S4 doesn't run that rich actually, a stock S4 with the wideband installed was in the mid 12's up to about 6500 rpm, it does go rich after that, but it also runs out of airflow.

i think the S4 AFM has enough measuring range to figure out a couple of mild mods, but if you're really making power with it, it does get a little lean.