Im at my wits end with why my car is cutting spark between 6300-6600 rpms. The tuner and I confirmed the fuel cutoff is commanded at 7500 rpms and in park/neutral it will reach 7500 rpms no problem. However, under load the car cuts out.

Plugs are the NGK -9 (1085) plugs gapped at .028 which are non resistor and I think they may be causing the issue... I'm running these as i plan to spray around 300-350.

Has anyone ran these plugs or had weird issues with the non resistor style plugs?

Just came across the NGK #5722 which is a -9 non projected tip AND resistor plug.

 

Engine specs will help these help you. Through my research for my motor similar to yours. I'm going to be starting with a 7 plug for NA and some nittrous then changing plugs as it needs. Hopefully some more knowledgeable people chime in so we can both learn.

 

Yes i should state that motor has the following:

2002 Trans Am
403ci Ls2
Stock coils
Msd wires

I came across the NGK BR9es (5722) plug which is a resistor plug but is 13/16 but dont think that matters on the Ls1 heads. Guess i can try those out. But really want to see if anyone has had an issue with these non-resistor type plugs

 

I know we talked the other day, but you get the problem figured out yet? Does it do it on both motor and nitrous?