npr350z

iTrader: (1)

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

OdesiTT

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.

dkmura

iTrader: (64)

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.

sportbiketed

iTrader: (11)

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

cashmoney03

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.

dcains

iTrader: (15)

Complete BS.

OdesiTT

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