Copper plugs?

[B shaw]

After reading many threads on here it seems everyone has different opinions about which plugs are better. Copper vs iridium vs platinum. So my question is who is running copper plugs at around 450hp or up and which plugs are you running? I have a set of autolite coppers (yes I know but they were free) in the supra now that are stock rating. After about a dozen pulls on a mix of low and high boost to dial in boost controller I checked the pulled things apart to check the plugs. I only pulled the first plug and have bad news. The plug tip is broke. It doesn't appear to be melted, looks more like it just snapped. I have found a set of ngk coppers stage 7, which is one stage colder than stock(stage 6) that I can have in hand in about 7-10 business days. I'm curious as to if anyone else here is running these plugs, and if so are you satisfied with them? If not ngk coppers then what coppers and what stage are you running?

Sorry if stage is not the correct term, its the way I've had them described to me and thus how I grew up labeling the hot/cold rating of the plug.

 

[SC61 MK3]

What is the autolite plug number you have? A lot of people run those plugs with no problem... When a tip breaks off usually has to do with an unsafe tune

 

[hvyman]

I run ngk copper. Pn 4644. Being that there only 12$ I usually just change them between 5-10k.

 

[suprarx7nut]

Heat range is the phrase you're looking for. Range 7 I believe is one colder than stock which should be good.

Regular NGK/denso coppers are my plug of choice, but I'm well below 450whp

Sent from my Galaxy Nexus using Tapatalk 2

 

[B shaw]

Autolite platinum. Ap5003. Those were the free ones. I have never used autolite before that. I can't remember the part number off hand for the ngk's I ordered today, but I can check the receipt when I get back to the house and post if anyone is interested.

Guess its a good thing I took it easy after I felt the miss this morning. It would slightly pop at idle, but when I drove it home after work it felt just fine. Normal driving and speed limit is not above 30 during the 5 min drive. Parked it and tore into it. Looks like it will be sitting for another few weeks now.

 

[B shaw]

Ngk plugs. Item number: 3330. 1.99 ea. 11.94 total. Those are the heat range ngk copper plugs ordered today.

 

[B shaw]

Also plan on doing a compression test and re tune if comp passes just to reassure myself that's not the problem. Somehow the prior code 51 is no longer showing up. Only thing that has happened since code was pulled is the plug broke and the car was parked. That's not the issue as it will not be driven again until it has new plugs, throws no codes, and is re tuned.

My next wonder is are the heat ranges categorized like gearing? Ie: high geared is not a high number, its the opposite. My question is... With ngk (or plugs in general) does a colder heat range mean the plug works better in colder temperatures? Or does it stay colder than the next heat range?

I'm really trying to make sure my supra is in tip top shape engine and mechanical wise before I attempt to drive it or think about moving on to the body or interior. I have some basic experience with the mk3(mostly trial and error with certain aspects the average person would not do), but with the current build and amount of money invested already I would much rather prefer to ensure rather than attempt. I'm open to any type/form of help/advice that can be offered. If its easier to refer me somewhere else where it's easily explained I greatly appreciate that. I have a build thread as well if that would help or if anyone is interested or curious.

http://www.supramania.com/forums/showthread.php?171075-89-T-build