Re: Spark plugs (
 

What ignition timing you need, and how much power you can push, before you detonate is one thing. It's based on compression, octane, etc.

What temp your plugs are is completely different. Too hot of a plug can cause detonation by becoing a hotspot (too cold, foulling), but colder plugs will not cure detonation if you have either exceeded design limits or have something wrong with your tune.

Average cruising speed of 120 doesn't make me worry. If you incessantly have to yam on the car from 80-120, and lack the self control to not make every one of them back to back WOT pulls, then I might worry. Do you have a dyno? Or failling that a datalogging cable + laptop and an EGT gauge? You can determine best timing and yank a little bit more timing out for safety.

Re: Spark plugs (
 

just get yourself a set of NGK's. I would not use the iridium plugs. Seen plenty of cars not make power utill they switch to the reg. NGK's instead of the iridium plugs.

Re: Spark plugs (
 

I have the a egt gauge, and the complete zeitronix package and a laptop, on uberdata, my car idles high and I cant seem to fix it, so adjusting my distributor timing is hard as hell, I have to starve the engine of air to get the idle down, I have no vac leaks. and I cant seem to understand the timing adjustment in uberdata what is needed etc.I have the boost timing set at .70 right now
the good thing is after switching to the colder plugs ngk-4554, the egt stays at 1500deg in boost, but when cruising at high speeds, it goes to 1900 plus maxed out the gauge scary. the car runs great and pulls hard as hell sc61 no lag during shifting which make suspected my compression being too high because of the head.

Re: Spark plugs (
 

Iridium has a great following with the entire supra crowd. Many other boosted crowds are following suite. There's nothing wrong with using them at all.... Once you get past the cost.
The good news is they're much more resistant to damage than a copper plug. The bad news is you'll know it quickly when you're melting a $1-2 copper core plug.


One step colder on NGK & Denso plugs. More than that without running insanely large power is just a waste.
Their heat ranges are much wider per step than the "traditional American" plugs the 2 heat range rule is based on.

Re: Spark plugs (
 

Iridium are a non-performance design. They accel at being hotspots. Regular electrode plugs don't melt unless you are doing something stupid.

Re: Spark plugs (
 

exactly, stick to NGK BCPR7ES, low cost and heavy duty

Re: Spark plugs (
 

I been running the zex plugs for a while now and work great for me, they have a colder heat range than stock and you don't have to gap them.

Re: Spark plugs (
 

I buy ngk BK7RE in bulk, but I found out that ngk-4554 runs way better in my car. so I am fasing out the 7 and in with 8's 2 steps colder

Re: Spark plugs (
 

I like BRK7E-11 for low power cars, or serious minded (at or a bit over 200 whp) mild NA cars. Most anything past 200 whp is going to want colder.