I was doing a few runs today and my car kept misfiring at higher boost levels
and it was perfectly fine when I lowered the boost.

Im currently using NGK BKR7EIX plugs, they are one step colder and gapped to 0.32"

Should I go another step colder with a smaller gap?

I read in the evo forums that you should go one step colder for every 100hp gain.

Any suggestions?

 

7's are fine but loose the iridiums. i use standard ngk vpowers at 15psi on mine. and i belive that 8's would be "too cold" if you know what i mean.

 

+1. Don't go any colder than BKR7E and move away from the iridium plugs. I run NGK copper plugs in my motors.

 

so the BKR7E plugs will be okay with 300+ whp?

 

searched around and these plugs seem to be popular with the turbo community.

unfortunately these are all special order so I cant give them a try until tomorrow.
ordered 2 sets since they need to replaced more often.

 

Does anyone know of any spark plug tool that can gap lower than .025"?

 

found this online http://www.restockit.com/Spark-Plug-...filiateprogram

 

It looks like it only goes down to .010" because of the gauge.

The lowest I've seen is .025" and my car misfires with that still

 

hrmm.. ever thought that our coilpacks just dont supply enough spark to begin with?
i didnt have any misfire issues when i was at 16 or 20psi on 93
and that was with the bkr7e plugs also..

 

maybe i need to replace my coils / wires...

i'll have to check them out

 

You might want to look into switching up to a DSM ignitor & coil for a better/more reliable spark.

 

MSD can hook u up.

 

You can use MSD coils if you want, but you'll still need the DSM ignitor to run a wasted spark setup. Your best bet is to run a setup like this:

https://www.evolutionm.net/forums/ev...stock-ecu.html

It's inexpensive and is good up to around 600whp. The coils shown are better than a stock DSM coil, but a stock DSM is still way better than the coil pack setup on the 4G94.

 

I'll have to look into that, thanks senate.

BTW I checked my coils / wires resistance and they are still within spec.
I guess I just reached their limit.

Looks like I'll be replacing plugs every 1k miles until I swap out the ignition