Angerman

Dont mean to thread jack but I dont feel like starting a new thread. I heard 1-step colder plugs usually range from an add to hp (75-100hp) before you start going steps colder. I was thinking of doing a 1-step colder and heard NGKs are the "best".


Are these the 1 step colder? http://www.amazon.com/NGK-BKR8EIX-Iridium-...g/dp/B001B6VUTM

Will work fine with my setup? I plan on getting a header soon and also will be tuning in summer. (mods are in sig)

8kGoodENuff

When I got tuned with my full bolt-on setup, the tuner suggested to use 1 step colder plugs but they definitely didn't work out too well. The car ran normal to about 5000 RPM and then after that, the car would just sputter and hesitate. He even rechecked the gapping to make sure they were correct, and the gapping was fine.

Swapped the original plugs in again and the car ran great.

Andre

8kGoodENuff

What plugs did you swap in?

Andre

Gernby

It actually did work out fine for you. It is best to run the coldest plug that you can gett away with. For you, that is the original plugs. I suspect that I can only go 1 step colder than OEM, but I do plan on trying an even colder plug just to prove it.

wadzii

a change of one way or the other as far as heat range goes is not likely to make a difference on a single dyno pull for a mostly stock car.

if the plug is too hot then you will get some pre-ignition or detonation, it will probably take a few pulls on the dyno to see that.

if the plug is too cold, it will foul itself out under normal driving conditions.

If you drive like grandma, keep the stock plug in it. If you drive like an ass go one step colder, the plug will last longer.

If you swap to a colder plug you either got the wrong one or a bad set of new plugs. New plugs should always pick up power over old even if the heat range is off

Gernby

If you were to do back-to-back dyno tests with a brand new set of cold plugs and a brand new set of stock plugs, you won't see any difference. However, if you run the cold plugs for a couple thousand miles, dyno test it, then run the stock plugs for a couple thousand miles, then dyno test it again, you will likely see a difference in power. Over time, the colder plugs will likely wind up causing the ECU to reduce the amount of knock retard, which will lead to more power.

The reason why I believe this is because I've seen this when I datalogged my friend's '02 S2000 against my '02 S2000 (with colder plugs) years ago, and also when I datalogged my brother's '06 S2000 against my '08 S2000 (with colder plugs). In both cases, my S2000's were running more ignition advance by a couple degrees.

Gernby

BTW, here is a graph from the datalog of my '08 and my brother's '06. The red curves are from my car, and the blue from my brother's. The top lines are the ignition advance, and the lower lines are the knock retard. As I said above, I believe the reason for my car having less knock retard is due in large part to my colder plugs.

BTW, ignore the top chart (Knock Level).

MBHs2k

When you install new plugs dont you have to give it some time for the car to adapt to the new plugs? i thought i have herd that before.

Gernby

Not unless the old pugs were REALLY messed up.

JuicedS2K

My ap2 blew up out of no where when i ran 1 step colder plugs...


Just playing, i run heat range 8 (1 step colder) all year and im N/A.