RxSeven1

iTrader: (2)

so i was reading some past threads on running 4 ngk 9s....i read that if your close to stock to run 2 7s and 2 9s, but with more mods all 9s would be better? my qustion is whats are the ideal heat range to run with these mods?

stock twins
apexi intakes
fmic
dp, mp, cb
pfc
no airpump
soon to be non seq

RX-7racer88

Normaly on the more mild modified, you can go with all 9s. With what you have sounds like it would work out ok.

rynberg

You should be running all 9s with those mods. You will not foul them unless you drive like a grandma 99% of the time.

Larz

Will the 9s really make a hell of a difference? If so, why? I've heard of guys switching to 9s for winter use.

desmond

what qualifies as grandma? i drive my car everyday, so most of the time i strive for decent gas mileage with the occasional sprint. would this type of driving foul 9's too quickly? my mods are full exhaust, intake, pfc

1QWIK7

iTrader: (33)

I think he means the occasional WOT from time to time. Not 24/7 wot but use good judgement. If you're driving the car under 4k rpms for like a straight month, i think they'll foul up pretty good.

twisted7

iTrader: (3)

i thought u could unfoul these spark plugs pretty easily...as in bringing them back to life after they have been fouled?

RxSeven1

iTrader: (2)

i would say i drive spiritely

YoshiFD3S

iTrader: (19)

FD's were MEANT to be driven.

:]

Matt Hey

9's may be safer during the winter with more air getting forced into the engine but the 9's will run rougher until the car is warmed up. A little roughness is fine where it's not too cold or when making longer trips during the winter. Otherwise stay with 7's (leading) or 8's (http://www.sparkplugs.com/results_cr...UR8EQP&x=0&y=0) and stay off the throttle or better yet drive a beater. Swap back to 9's all around (or 8 leading/9 trailing) the rest of the year. A colder plug than what's needed can make less HP, get worse mpg, and run rougher.