View Full Version : Colder plugs

05-27-2012, 10:04 AM
Hey all,

Trying to find a set of colder plugs for a JRSC setup but can't nail down a specific part number from any manufacturer. Moss isn't much help, I tried calling but they couldn't give me a direct answer as their sales monkey only knew how to take credit card orders.

Do most of you leave the plugs alone or do you change them, if so what are you running and what's the p/n?


05-27-2012, 10:20 AM
colder plug just means that it will disspate heat in the tip faster.

So if you're running lots of boost, the combustion chamber gets hot. If the plugs tip gets too hot, it can cause detonation, so colder is safer for high (higher than stock) boost.

Under normal driving, cold plug will foul, so thats why it's not a factory item. Some foreign cars run hotter (for better gas mileage) and they use colder plugs to make up for it. I personally am running densos ik16 and have never had a prob. They were recommended to me by Remmy @ corsport

05-27-2012, 12:35 PM

K20a3s run at cold rating of 6
K20a2/z1 run at a cold rating of 7

8/9 are for series boosters.

I would say 7s would be good till like 300+

05-27-2012, 05:24 PM
1 Step colder than stock Shaun.

05-29-2012, 10:39 AM
Thx!! :)

06-01-2012, 02:06 AM
Ngk or Denso plugs for a rsx -s will be one step colder. Denso part number is IK22. And that will be 1 step colder for the a3. Also look into a hondata intake manifold gasket for ur jrsc setup. Moss might still sell em. If your just running the street kit your stock plugs will do fine. But for the race kit 1 step colder is plenty. Just remember stock rsx - s plugs = 1 step colder a3.