As the title states, how often do you change your sparkplugs? Should you change more often if you are running more power say above 300whp?

 

every day lol


is ur car a daily? if so i personal would every 6 months, thats just me tho

 

About every 8000 miles.

 

I drive my fd for 3 weeks daily and then it sits for 3 weeks while I alternate with my other car. I was thinking every 15k miles would be good but I am new to this car....
More input would be appreciated.

 

No reason to change any more frequent than every 20,000 miles with conventional and 35,000 + with platinum, in my humble opinion, if you have a well-tuned engine.

 

I should think it may also depend on how much boost you're running, no? Wouldn't higher CCP's effectively wear down the electrode quicker then lower CCP?

Personally I like to take mine out for inspection/cleaning every other oil change or so...

 

As someone who has had more than his fair share of stripped spark plug holes over a 35+ year period of time, and the accompanying SUCKING that comes with it, I have come to be very liberal with the sparking plug replacement schedule. I've found most American V-8s to be good for 50,000 miles, and most import I-4 and V-6 configuration to be similar. I pulled the plugs out of my dad's '96 Park Avenue that had about 130,000 on them and...they didn't look bad at all, frankly. Replaced them, but...really wasn't a reason to.

 

FWIW, I once got about 60,000 miles on a set of stock NGK plugs in a stock FD before it started missing. They were worn pretty badly when I finally replaced them.

In the trailing w/stock ignition I seem to be getting around 20K on bur9 platinums before I change them--as the tips round off and the gaps go up, the firing voltage increases dramatically, increasing the likelihood of a misfire under high boost.

For the leading, I use an MSD 6a which tends to wear plugs faster (but provides for a more reliable ignition). Using conventional, copper plugs, I'll get 5,000 or so miles, but at $3 a plug, who cares.... The BUR9's in platinum will go 10,000-->15,000mi, or about once a year for me. The disadvantage to the BUR's is that you can't close down the gaps at all, which some cars (such as mine) seem to respond to.

Regardless of the plugs you put in, be sure to put oil (or anti-seize) on the threads so as to avoid the problems Baja spoke of in his post.

 

higher horsepower cars are going to wear out plugs faster. gotta pay to play. i use four BUR9EQ (copper) and change every 3-5k. But that's what a decent sized single turbo setup and HKS twin power.

 

I change mine once a year regardless of miles. Same thing with my oil (every 3 months regardless of miles)

I dont daily my car and i do alot of idling (mostly in the winter time to warm up the car etc).

Mine is due in 2 months speaking of plugs lol

 

i have a new question to ask, what kind of plugs are you guys over 300hp running and how often do you change them?

 

I'm running NGK Racing plugs in mine, 9 (badged as Greddy) and 10.5 (R6725-105) heat ranges as was suggested by my tuner in the UK.

I have sequential twins pushing 17.5psi at the (estimated US number, UK dyno showed 340whp) 400whp mark.

 

NGK 9's for road - I used to run 10s, but the were not getting up to temp on the road, fine for track though..

 

ngk race ones, b10egv all around for me normally changed them every 5 months or so, but now i been fouling them out in 1 week so i am checking what it could be

 

9's are fine for even most single turbo setups, believe it or not--remember that is two steps colder than the stock leading plugs. In fact I prefer the 9's to the 10's I used to run because they don't foul out, they're not hard to find and aren't too expensive, they don't require gapping and you can use a regular socket on them. I have a T04R/T67 I run at 16psi on regular pump fuel with EGT's I've measured as over 1650 pre turbo. You have to realize that a 9 heat range is actually a very cold plug already. Most turbo passenger cars run a 6 from the factory. An 8 would be considered pretty cold. And lots of turbo piston engines will see 1600+ degree EGT's preturbo, very close to what a rotary will see.

The BUR series plugs have special design features to prolong the life of the plug and reduce fouling:

 

last time i ran thos plugs when i was going to get tuned got on the dyno and the tuner said my plugs were running to hot. and we switched to thos b10egv

 

I have my Greddy Race plugs (NGK R7420's, 9L, 10T) glass blasted after 10k km and then replace them at 20k km. When I replace them, the tip has started to show wear. They're probably fine for much longer but I'd rather have fresh plugs. My car see's a lot of track time at 20 PSi boost for sustained periods. That probably keeps the plugs clean which they always are but accelerates the wear on them.

thewird

 

**** man you go through alot of money then, i was looking at thos plugs and they are like 120-150 for 4 of them

 

LOL, I spend more then that much on just gas on a single track day. Not counting tire wear, brake wear, and just **** breaking.

thewird

 

i change mines out every 8000 miles just for the hell of it. bur9eqp's

 

6-8k is about all I used to get out of the standard NGK platinums (9s), then I switched to Denso Iridiums, and they looked almost new after 10k miles (where the NGKs would be down to a nub)....to say the least, I was sold on them for life....well worth the price of admission, and the car runs better with them to boot

 

BTW the way, you can extend the life of your leading plugs by periodically switching the plug wires between the leading plugs. I reverse them every oil change. This will balance out wear on the center/outside electrodes that tends to be uneven due to the polarity of the spark. The benefit can be considerable if you're using those expensive motorcycle or racing plugs. Note that this only works if the leading plugs are fired from a common coil, e.g., stock or "lost spark" ignition.