hey H-T.

i have a built ls/vtec motor making the said power. im currently running BKR7E spark plugs. i feel i need colder range. are there any you guys recommend for 500+ hp? im upping the boost.

i did research already,

came up with these two.
- R5672A-8 7173
- R5671A-8 4554

what are the difference between these two?

 

im runnin the bkr7e on my k20 turbo. never had a problem. 400hp daily driven, 600+ on race gas.

why do you feel you need a colder plug?

 

good question.

1. It gets hot here where i live. through out the summer (June-september) between (80-100f)

2. through out all of the other seasons. IE: Winter, Fall, Spring. (october-may) it never falls colder than 45F

 

Only if your EGTs are getting out of hand outside of 1600F at WOT is a "colder" plug like an 8 needed. You should be fine with 7 heat range, regardless of outside ambient temp, unless the tuner has not accounted for it in their calibration of the car

 

I run NGK R5671A-8 gapped at .020". My car makes 500hp at 25psi on E85. My EGTs are below 1300*F.