James@ShorTuning

What does the injector pulsewidth show when logged on the pull? Pulsewidth when graphed should be gradual and smooth. I suspect with the IAT relay mod that it may be triggering some adverse affects to the fuel being supplied to the engine. What is the dynamic airflow cutoff? ~4500rpm? This would be my guess because IAT directly affects fueling while in SD or SD/MAF blended mode which is below the Dynamic Airflow cutoff rpm (normally set ~4000rpm stock).

This is why I openly speak out NOT to use this method because IMO it's a hack in itself because now the engine will not run like it's supposed to with the IAT tricked, especially if it is in fact SD tuned. Do a test with the relay kicked and disable the solenoids so they will not fire and see what your NA fueling is with the IAT relay enabled.

Post back what you find with the pulsewidth of the injectors...

Sales@Tick

iTrader: (3)

James,

Unfortunately the owner has already picked up the car. Did you see the last dyno graph by chance? I should of contacted you about this, as I was going to, but forgot. Been so freaking busy.

James@ShorTuning

Yeah I saw it, it was much better. I wouldn't bat an eye at 13.0 afr on the juice especially if timing was carefully watched. I don't run any of mine as rich as 12.0... My formula was never richer than 12.8 and after peak tq it leaned on up to 13.4 LOL. It loves it. Thats on a 100k mile sbe with .080" 2.25" valve reliefs cut on a dual nozzle 52jet in one and 46 jet in the other dry.

You'll see how when it was lean it made more power too! Once it started richening up the power fell slightly.

Glad you guys got it taken care of.

Sales@Tick

iTrader: (3)

Ehh, I guess we took care of it as best we could. Wish we could try what you just mentioned though. Oh well, the tune is very safe and the AFR is nice and gradually sloping richer as rpm's increase. if this were a race car we'd let er' eat with the good ol' leaner is meaner, but with all the issues we were having we got gun shy to say the least!!!

I always targeted the same AFR values on the kit with my car (12.5-13.0) and as you said, it loves it. Much more responsive and didn't get that flucuating rpm sound as it went down track in high gear which is a big indicator the motor is trying to tell you that it's too rich. On nitrous, lean is truly mean and not only is it mean, it is the correct way to tune it. People try and tune nitrous too similar to boost. Needs to be tuned exactly the same way you would tune a N/A set-up as that is what it truely still is.