I'm told I need to run a spark plug that is one heat range colder than stock when you increase the horsepower by 75. I assume that means both leading and trailing. Is this correct?

The stock NGK part numbers are BUR9EQP

and

BUR7EQP

The nine and seven I know refer to the heat range. However these is no BUR10EQP spark plug.

Any suggestions on part numbers for NGK?

Thanks so much!

 

Read up on spark plugs, there's TONS of options and such out there. For most people, just running all 9's is fine - that's what I do. It really depends on how much horsepower you're looking to run.

I would look at the single turbo forum, they're constantly playing with spark plugs. But, for a start, I'd just run all 9's. Reliable, don't foul out, and work just fine.

Dale