shanec

Glad to see more E-Force'ers here since my install last September.

Its running really well. The only issue I have, and hopefully its a minor one, is this:




The A/F looks very wavy, especially at high rpm. And notice the hp dips at high rpm, especially in the red curve. At this point, the car was blowing short puffs black smoke (unburnt fuel) through the exhaust tips.

Anybody know what's going on here?

I am running OEM COP's. I've tried new OEM COP's as well - haven't been back to the dyno after doing this, but my wideband still indicates A/F bouncing around as shown in the chart.

I am also running FRPP plugs gapped at 0.03.

The only other thing I know to try - which SHOULDN'T be necessary is to gap the plugs down more or try aftermarket COPs which I understand are universally pieces of crap.

Other mods - Bassani LTs, catted-X, Bassani Race mufflers. I'm on my Nth set of O2s, so I doubt have bad O2s. O2 replacement has been an effort to handle delayed response codes that occasionally come up due to longtube headers.

The tune is from JDM. No help there as of yet.

Simon1

What's the fuel system?

This is not a custom tune correct?

Gapping at .03? It could be anywhere from .030 to .039. There is a difference. Get a wire gauge and check every plug.

Does the car feel like it stumbles during the dyno run?

shanec

GT500 fuel pump, 60lb injectors - should be overkill for my 450rwhp

I measured the gap on each plug to be 0.030

Tune is JDM's email tune.

The only symptoms of a problem are what you see on the chart and black smoke during those hp dips. Can't feel or hear anything odd on the street or dyno (other than the smoke and that chart).

JDM's opinion is that it is spark blowout and that I should replace my plugs. The car has <20,000 miles. The supercharger and this set of plugs has about 7,000 miles. Unless I just got a set of bad plugs right out of the box, I don't know how the plugs could be bad.