Anyone around here do this? I used to do it on my other vehicles but never thought about it on the z, I just always popped the new plugs in. Would it really matter on our cars? I just was thinking bout it, when my buddy told me between that and putting on a port matched tb on his civic gained bout 9whp in 30 mins, I figure half was just from replacing his old spark plugs. But I've always heard good things about indexing and side gapping

 

Same question. I want to index my new plugs, and question is, where is located intake valves if look at the car from the front.

 

Indexing plugs is worth the effort if the engine is using high compression pistons with huge domes. For engines like the VQ35DE/revup/HR, the use of indexing is overrated. It's already got a four valve head, so swirl and fill is double what an older head would get. The domes on a stock OEM VQ piston are not huge, so piston-to-valve clearances are not a factor. I wouldn't bother.

 

9whp?
Did he swap about plugs and TB in between dyno pulls to ensure that all the conditions were the same?

 

On a street car it's a waste of time these days. For an all out race car where you are looking for that last horsepower it would be worth it.

 

Complete BS.

 

this is according to buddy's but dyno, and Civic guys have a very sensitive buts