Pseudonym

iTrader: (3)

Im going to replace my spark plugs because the headers are out. I have been running NGK TR55s with no problems, but I feel like there is a better plug for my application. The motor is an NA 402 with TFS 225s and a big cam. It makes about 550 whp.

I am looking at NGK BR7EF (2 steps colder) or TR6 (1 step colder) which is better?

10secZ28

iTrader: (6)

i would use the 7 non projected tip

Pseudonym

iTrader: (3)

Thanks, that is what I was leaning towards.

Jontall

I think the NGK TR6 would be cold enough, but the great thing about copper spark plugs is the price. Buy both sets and do some testing.

Pseudonym

iTrader: (3)

I could buy both, but I lack the motivation to do spark plugs twice. Especially because the longtubes will be installed.