The ones i sold you work the IKH24's. but I know there's better out there that cost a arm and a leg. I'll let Aaron answer your question though since you addressed it to him.

I never heard of the other ones mentioned in here until just now.

Pete also mentioned his HLA came loose on his head and in turn of that coming loose it destroyed cams.

 

Funny to see the talk of plugs.

On the dsmlink forums in like 2003 I made a thread about trying out different heat range plugs. I tuned my car on non-projected 7s to the ragged edge. Went to the track, tossed in projected 6s and made a pass... It was a mess and the knock sensor saved the motor. Completely reckless on my part but I knew the knock sensor would save my *** in this case.

Went to non-projected 7s and the car picked up like 4 mph. No knock but the plugs still looked unhappy (highly stressed more so than unhappy). Went to the 8s and picked up 2 more mph. Plugs finely looked good.

I got told I was stupid and didn't know what I was doing and my results were bull****...

I've been running tight gapped 9s ever since... FWIW, the ONLY down fall of non-projected 9s is they WILL foul out if you try to run them above about 0.022". They can be very sensitive to rich afrs on launch control type "anti-lag" (lots of fuel, retarded ignition). You'll leave the line and every thing seems OK but the power just won't be there until mid 2nd gear.

Edit: haha went back and found the thread... I was running with the knock sensor disabled... A testament to the strength of the 4G63...

 

How the hell did that come loose? Someone finger tighten the 10mm bolts?

 

no they did not "come loose" when i got the head back from the machine shop the first time i just bolted the HLA on and screwed them on finger tight knowing that i was waiting for everything else to get back from the machine shop and stupid me forgot

cams werent destroyed. one cam cap journal had a little scoring to it so i sent that cam to Delta cams for them to repair it. good as new

anyways, my 3586 turbo kit is almost done, round 2 here we goo

 

IIRC Chad Block recommends the 8bpreix iridiums. So you are using the 9 heat range non projected non iridium? I would expect some fouling as you suggested. It would be interesting to do a 8bpreix/9bpreix back to back test.

 

I have used stock ILFR7H (7's), LFR7AIX (7.5), IKH24 (8's), and now run the IKH27 in 800+whp as a race plug. Some of what I use to determine is the setup, a 10.5:1 motor likes colder plugs for a lower power level than what you can squeeze out of a 9:1 motor at the same power. The downside is the colder plugs are a little more finicky about fouling out at idle so its a careful balancing act unless you just use them for race day and turn the car back down during the week.

I run what it takes and dont worry about cost since I prefer to beat the crap out of my cars. The only way you will really know is to do a plug chop on a fresh set at full power and then hopefully understand how to read what you see. 1.5-2 threads of heat is the magic number. Lots more goes in to it but that at least lets you know what heat range to be at.

We dont run high gaps on the 9's but they normally are only in 950+whp 4 cyl. setups so 0.016 to 0.018 is already pretty common.

Aaron

 

When you say 1.5-2 threads of heat I don't know what you are referring to. I had bpr8es in my car and after about 100 miles they would start misfiring. I swapped multiple sets and they would consistently start misfiring after a few miles. I have BPR7ES and they never misfire. Right now I have a 10.5:1 2.4 at 25psi. I tried reading plugs but never really got a clear answer on the heat marks and such.

 

It have been on 7's for about 7k miles and it runs awesome. They don't seem to ever need replaced either.

 

 

Thank you! I will look at my plugs in the morning.

 

excellent read....bumping for more info/knowledge...

 

good to know - looks like i'll stick with the stock range - thought the LFR7AIX but I guess it's a half step colder