Seriously, I've always use the platinum plugs in my car, but out of desperation, I threw 4 cheapo Bosch plugs in yesterday gapped to .44 Car runs fine, what the hell is the reasoning behind buying a $15.00 plug and $1.25 plug when you are going to replace them every now and then anyway? I'm being serious, they both give you the spark you need, so why do we go through the trouble of spending more?

 

life of the plug?

i have a friend who uses copper spark plugs, and he says he needs to change spark plugs every 5k miles or so (every other oil change roughly). this is in a turbo mr2. i dont know if that makes a difference.

$5 every 5k = $60 for 60k miles (copper) vs. $60 every 60k (platinum) the 60k miles is only an assumption...

 

Well, since my car runs rich at idle with the ITBs, I will need to change them out more often. So I guess staying with copper plugs isn't a bad thing. Can someone also explain if going colder or hotter will effect them fouling up faster?

 

I used copper plugs in my Turbod Mr2 as well. And they did NOT last long at all. I think i changed them every oil change, but the risk of misfiring and engine detonation was lower. Running platinum plugs in the Mr2 was not the best idea one came up with. Running a colder plug also insures a less risk of misfiring or detonation as I had to drop to a colder plug in my Mr2 when i raised the boost to 14psi, 15 psi on half and half racing gas/ 93 oct. I believe the Denzos are some of the colder plugs out there to use which is why theyre better, someone correct me if im wrong.

 

well its going to be a different quailty of spark due to the conductivity and gapping of the plugs. The copper plugs will not last as long, but do run colder than your previous plats which will result in increase hp with your application. Also the quality of the plugs are affecting the price, some are fabricated with a weak porcelain base which can cause destruction of the plug. Youre not the first to say the coppers work fine, especially the cheap 1.50 racing copper plugs. Many nitrous injected cars have switched over to them because they work great for a moderately good time frame and can be changed out when needed.

with my settings I found the denso iridiums were an overall performer becuase they worked fine even when NA.

 

Arnold, so if I plan on changing my plugs every 1000 to 2000 hell maybe even less. Since I hardly even put 4000 miles a year on the car. Does it make sense to stay with the iridium or platnium? I have to think that the copper plugs are sufficient for what I am dealing with.

 

hey, Denso's dont cost 50 a pop for nothin

 

Platinum tips cannot dissipate heat as fast as copper can from their tips so they run "hotter" even if they're at the same heat range. So if the combustion chamber temps are on the hot side, the platinum tips can glow and may spark the gas again on another time in the stroke causing misfires. That's why it's a bad idea for F/I.

Dan, at the price of the coppers, and the fact that removing them frequently to check on the condition of the plugs, I think that's the best bet. BTW, at idle it doesnt run rich only when cranking it.

 

I thought it did? Maybe it ran lean at idle? I guess I should just go outside and check.

 

since your application runs so rich you should stay away from the platinum tips. The coppers are absolutely fine for your setup. The only thing you should look for is a copper plug from Champion Racing that has a long porecelain base. The reasoning behind it is two purpose. It will prevent less fuel saturation and also create a stronger base to avoid a spark plug diaster. Some even have a slighly coated enamel which is even better.

BTW I found an AEM tuner close by after talking with him about your application. He has been the crew chief and built many motors. He was with Bergenholtz racing and developed their 9 second CRX and has worked very closely with TODA and AEM. He seemed very knowledgeable and had a few questions and recommendations reagrding your ITBs that I was unable to answer.