what would be the downside to using the plug that's 2 steps colder with my mods instead of 1 step colder? Would I lose some power or run more rich or something?

 

I agree with Adam that a person should not need a colder plug for N/A. The following is info on plugs:

Heat Range
4= 1 degree hotter
5= stock (IKH16 or 5-11A)
6= 1 degree colder (IKH20 or NGK6-11A)
7= 2 degree colder (IKH22 )
8= 3 degree colder (IKH24)

 

just talked on the phone with autocarparts.com and they say the 20 is 1 step lower and the 22 is 2 steps lower according to their Denso documentation. He also went on to say they're one of the larger Denso venders and have and sell some of Denso's more rare plugs. He assured me like 3 or 4 times they're 1 step colder so I dunno, we'll see.

I'm not sure why my mods are misfiring the engine - it only started happening once TS flashed my ECU. They recommended I get colder plugs. They hooked their computer up to my car. It doesn't happen all the time, but when it does, it's mild and between 1-1.5k or so rpm. Then he said my Tilton was probably the culprit because of how sensitive it is down low. I had them permanently program my idle to 900rpm for the JWT cams (yesterday I found out I probably could have had it set at 850, but oh well)

From what I've read on this site, getting a higher quality iradium plug is better for the engine anyway or can possibly even increase power ever so slightly

 

like mjedens said, ikh20 are only 1 step colder and the 22's 2 step. I have the 22 in my car but then again my car is FI

 

Thanks for all the responses to my question!

 

zachcrosen

I'm not an expert, but I believe it has something to do with the temperature of the tip of the spark plug and going colder can combat engine misfiring if it is occuring - someone correct me if I'm wrong

 

Thanks. So is there a benefit on going with 1 step colder plugs on a N/A Z?