00ChevyScott

iTrader: (10)

I originally had some ACDelco Iridiums (41-985) aka the factory plugs in my motor. The motor has about 25,000 miles on it or so and had been running the .040 gap that is standard on the 2006 Chevys. Well I just picked up some TR55s from work and am running the pre-set gap of .055 (factory settings for 2000 is .060). I have read with every ~ 50 hp added on top of factory power levels, the gap should be decreased by .004, so I figured .055 would be good enough and isn't worth messing with.

I noticed right away my truck had a bit deeper tone to it, and did idle a little bit different. My first impressions driving it down the road were that it felt like it had more torque and more bottom end power. I let it warm up and drive it around the neighborhood before I hit a long stretch of road. I did a few WOT pulls, where it feels like the power is the same or a little bit less than before, but we will see how throwing a new tune in there affects that next week.

Hopefully swapping to a more suitable gap, and running a proven performance plug will be worth all the trouble. All of the plugs I pulled out looked decent, haven't gotten a chance to check the gap on them yet to see how much of the electrode had worn down.

budhayes3

iTrader: (19)

25k is nothing for iridium plugs, you could have let those ride quite a bit longer although copper is a better conductor than iridium. .055 should be a good gap for the TR55's, you could open them up to .060, but I wouldn't go much bigger than that. You probably won't notice any wear on the iridium electrode, unless one of the tips breaks off...be careful checking the gaps on the iridiums, as the electrode is micro welded and can snap off quite easily, giving you an in-correct reading. You could save those plugs as back-ups in case you need them.

00ChevyScott

iTrader: (10)

I am saving them as back ups, but the gap on those is too small for my 99-02 PCM spark dwell tables in my tune. It's easier to swap plugs/gaps than to change the tables so I picked that.