How often to replace TR6-IX plugs (upper pulley only)

[SpectorV]

How often to replace TR6-IX (iridium versions) plugs (upper pulley only with intake/exhasut/tune). Currently they have been in the car about 10k miles or so, just driven on the weekends not really raced.

I hate putting plugs in (4 thread heads and cai sucks to remove) so I feel like ive put it off, but want to know what a good interval is.

Thanks!

 

[Bdubbs]

I'm very picky with my car. It would take me forever to put 10k on mine. I've had my car for 4 years and only put 6k on it. Spark plugs are actually pretty easy on these cars. Hell I think I've changed mine atleast 4 times since I've owned my car. I do use a in/lb torque wrench and torque them to specs just for a piece of mine.

If I was you I'd change them now, 10k seems to be a good place to start. At least you can look at all the plugs, and make sure none of them are loose and backing out.

 

[SnakeBoostE85]

You shouldn't really ever have to replace them, but depending on how often you rip on it or go to the track I would would pull them and re-gap every 5000 miles or so. When you pull them to re-gap if the electrodes or tips look worn, replace them.

They come out of gap easily because of the amount of heat generated during WOT pulls. They expand and warp and eventually over time the gaps open up.

This happened to me after I did my whipple install… I couldn't get the damn thing to stop blowing out, I almost replaced my coils until I thought to just check the plugs and verify the gap. So I pulled my plugs and noticed some were as far open as .038 all of them were well over .030. My original gap for just upper was .028 and that's what I use today even at 20 psi on the whipple and it works fine.

Reminds me… I should probably pull them again. Its running fine right now, but might as well take an hour 1 weekend and pull them out.

 

[SpectorV]

yup I really should pull and just check them, replace as needed and check gap..... that will probably be my project soon as I have to do a coolant change and fuel filter also

thanks for the info! current gap is .38 (or was when I put them in). I barley every do WOT pulls where heat would ever be an issue.

 

[SnakeBoostE85]

Even with just an upper pulley .038 is a pretty big gap. Are you sure your not getting any blowout? I know every car is different but I don't think anyone with an upper runs a gap that large. I think the general guidance is start at .032 and work your way down from there. Mine was a finicky pain in the ass. Anything more than .030 was blowout city.

 

[SnakeBoostE85]

Re-cap on this for those interested....

Ever since I switched to running E85, I no longer have problems with my gap opening back up. I just pulled them and gaps were all within 0.001 of my original 0.028 gap and I have whaled on it on and off for several thousand miles since I last checked them. E85 ROCKS!! The cooler combustion makes such a huge difference on everything. So much better for high boost applications. Its finicky to tune, but once you get it right, there is no going back. Pump gas absolutely sucks balls, never again!!!

 

[01cobravortech]

I can tell you first hand from running NGK TR7ixs for like the last 45k, and they come with the out of the box gap of .034 - .037, that I have never measured anything wider than .037 running strictly Shell 93/Costco 93.

Best plugs ever and I'm just an upper pulley guy at the moment (2.76).

I change them between 8k - 15k. I go sometimes 15 months before I do a plug change. I wait for those Advanced Auto 35% off coupons.

 

[SnakeBoostE85]

I can tell you first hand from running NGK TR7ixs for like the last 45k, and they come with the out of the box gap of .034 - .037, that I have never measured anything wider than .037 running strictly Shell 93/Costco 93.

Best plugs ever and I'm just an upper pulley guy at the moment (2.76).

I change them between 8k - 15k. I go sometimes 15 months before I do a plug change. I wait for those Advanced Auto 35% off coupons.

you run a 0.34 to .037 gap with an upper pulley? Have you ever checked for blow out on a dyno?