Scrub

iTrader: (25)

What spark plugs do you guys/girls recomend using?

Bucrx7

What kind of mods?

Badog

BPU, go with NGK EQP 9's (that's not the whole number, the stock 'trailing plug', but platinium) all the way around.

Ported, single, extra fuel and ignition and racing? Go race plugs. Not racing and not so high boost? Go with 9's or 10's.

I change the plugs every 2 oil changes. Helps to buy in bulk or from a good/cheap source!

gohorns

for stock boost levels - 7s leading 9s trailing
mild mods and > stock boost - 9s all the way
I have not tried 9s all the way so could not comment on that but for stock boost levels stay with mazda's recommendation. Just my .02

Scrub

iTrader: (25)

Thanks, i was thinking either iridium or platnum. What do you guys think?

vudoodoodoo

Go w/ the stock NGK's. I run the trailing plugs (9's) for both leading and trailing.

wstrohm

My '94 Workshop Manual (page TD-4) lists the following NGK part numbers:

For leading plugs: BUR7EQP*, BUR6EQP, BUR7EQ, BUR6EQ

For trailing plugs: BUR9EQ*, BUR8EQP, BUR9EQP, BUR8EQ

* means it is the factory-supplied or "standard" plug.

The "P" suffix on any of the above means it has a platinum center electrode.

Plug gap recommended is 1.1 - 1.7 mm (0.044 - 0.066 in)

---- Bill

rxshun7

I was told all 9's are the best for modded FD's. Get the stock ngk's from the dealer. i think the part number was bur9eqp or something like that.

Tom93R1

iTrader: (2)

If you have plugs that can be gapped then you picked up the wrong ones

Scrub

iTrader: (25)

How much do they run from the dealer?

Scrub

iTrader: (25)

oh sorry, i forgot. What about wires what kind do you recommend? I had Nology hot wires on my last car, they didn't seem to bad.

DavidDeco

My car seems to be running better since I changed to to 9's all around from the 7/9 combo.

JUSTgotMINE

NGK plugs and wires. I got mine from mazdaformance.

fdracer

that's still 9-10 bucks a pc. that's not to good of a deal.

Scrub

iTrader: (25)

Thats not to bad, i would have thought like 75.

atihun

I would recommend you use the non platinum plugs; BUR7EQ (leading) and BUR9EQ (trailing). The only benefit to platinum plugs is that the tip lasts longer, however our cars tend to foul plugs very easily as they run on the rich side. I replace my plugs every other oil change. The non platinum plugs are about 2.50 each at Pep Boys; yes they are NGKs.

If you have several mods, you should run all 9's, colder plugs.

Scrub

iTrader: (25)

what does it mean by "colder" plug anyway?

atihun

The spark created is not as intense/hot as a 7 rated plug. I believe it has more resistance built into the plug.

fdracer

dude, you can get plugs at pep boys? i've called all the parts shops around where i live and no one stocks these. neither the platinums nor coppers.

while we're at it where's the cheapest place to get plugs guys? i get mine for $6.69 ea. plus shipping for the platinums.

atihun

At PepBoys, you need to ask for leading and trailing spark plugs for a 1991 RX7. They are NGKs, same as from the dealer, minus the platinum tips.

At $2.50 a peice it's a deal and it allows for more frequent changes so you dont have to worry about plugs fouling.

maxcooper

A colder plug dissipates heat better than a hotter plug, so the plug electrodes don't get as hot. If you have a "hot" engine, you want a "cold" plug. If you run a plug that is too hot for your setup, plug life will be reduced. It seems like a plug that is too hot might increase your chances for pre-ignition, but I don't know if that effect is real or imagined. So why not just run super cold plugs? Because if the plug is too cold, it won't burn off the deposits (oil, gas, carbon) and it will foul. A "9" plug is colder than a "7".

You can run platinum leading plugs and non-platinum trailing plugs to save a little money. The leading plugs fire twice as often (because they share the same coil in a "wasted spark" configuration) so they tend to wear faster than the trailing plugs.

-Max