Pulled my stock plugs yesterday - pretty & clean. Been running 19% ~ 1000 miles now. No discernable pinging.
EVERYONE KNOWS THE JCW KIT COMES WITH COOLER PLUGS.
As of yet, I don't seem to need them.
Is there any TANGIBLE evidence indicating the need to go cooler?

 

Actually, you will probably not hear any pinging. The ECU can back off the timing as much as 11 degrees (I think) if pinging is detected. If it backs off only a few degrees,that will cause a loss of hp.
I put in IK22 when I did the 15% pulley.

 

bodinski,

I would say to be safe, put them in. It will not necessarily hurt your engine if you don't have them, the ECU is smart enough to detect detonation and will back off timing. As it backs off timing you will loose hp. The colder the temperature outside, the less chance of detonation. As it gets warmer (as it does in Tenessee) your chances of detonation increase. You will never know if it is happening until you put it on a dyno or measure the timing. You may feel some loss in hp, but maybe not much. One range colder is usually in the $40-$50 range, depending on brand of plugs. For the price it gives you some added insurance and ensures that your car is running at it's peak hp.

 

Definitely not necessary but they certainly wouldn't hurt either. I've been running a pulley for 46k miles (15k with 15%, 31k with 19%) with the original stock spark plugs. I considered replacing them until I found out most aftermarket replacement plugs don't last nearly as long as the stock ones. So I stuck with the stock ones. No ill effects to my knowledge. The car runs great in all weather conditions including 100 degree heat with the A/C blasting.

 

I ran my 15% pullied car for over a year with the stock plugs. It was only when I upgraded to the UNIChip ECU that I decided to go to the IK-22s. I don't think I've ever had a detonation problem.

 

Has anyone chopped/pulled the IK22s after running with a pulley to see how they look? The stockers looked fine, actually, despite evidence of running rich.

As to the post about aftermarket plugs not lasting as long, the iridiums are claimed to last much longer than platinum.

Jeff

 

You will not detect detonation, nor will you feel it. You will probably only see it on the dyno. But a car that has it's timing backed off some could easily loose 10hp. For $40-$50 this prevents that. It shocks me that more people don't change them. Especially when people spend way more money on silly things like plasma boosters and plug wires. We have people spending $150 on plug wires but argue about not purchasing new plugs. Almost every reputable tuning kit, including the JCW comes with one range cooler. Again, it will not harm your engine if you don't. The MCS is plenty sophisticated to keep you from hearing the pinging like that from cars in the 80's.


Plugs like the IK22, will not last as long as the stock plugs. The stock plugs are rated for 100,000 miles. Part of this is due to the 4 prong design, the other is due to the actual elements used in the plug. Most plug manufacturers including Denso sell consumer brand plugs, and then OEM (100,000 mile) plugs. Plugs like the IK22 should be changed every 15,000 or so miles.

With all that said, in this month's edition of Eurotuner magazine, they noticed a significant difference in dyno hp, when changing out their aftermarket plugs with a fresh set of plugs. They saw a difference of 15hp, even though they couldn't feel the difference, it did show up on the dyno. So plugs do make a difference and bad ones can have a negative affect.

I would just think from people who spend the extra $100-$150 for the Alta intake, because of the extra 1 to 2hp, that they would put it something like cold range plugs for $40-$50 which definitely has shown (in hotter weather) to increase performance (or actually prevent the decrease of performance) far greater than 1-2hp.