necessity of colder plugs with boost

[rentedmule]

Do colder heat-range plugs really make a big difference in a mildly boosted application? I know the theory behind heat ranges and the relation to fouling and knock prevention but I'm wondering if the difference is tangible in a mild build?

I'm running delco R42LTS's now and I have a feeling that they may be too cold for my build/driving style. I rarely see boost on a day to day basis and it feels like the plugs are starting to foul already. I'm going to swap them out regardless but I'm wondering if I should go with R43LTS's (one heat range down from stock) or stick with the stock spec plugs. NGK TR6IX's are pricey and I'd need to order them in so I'd rather not use those.

For those that don't know I'm running methanol injection for knock suppression which I'm sure can factor into this decision.

[94s10]

Do colder heat-range plugs really make a big difference in a mildly boosted application? I know the theory behind heat ranges and the relation to fouling and knock prevention but I'm wondering if the difference is tangible in a mild build?

I'm running delco R42LTS's now and I have a feeling that they may be too cold for my build/driving style. I rarely see boost on a day to day basis and it feels like the plugs are starting to foul already. I'm going to swap them out regardless but I'm wondering if I should go with R43LTS's (one heat range down from stock) or stick with the stock spec plugs. NGK TR6IX's are pricey and I'd need to order them in so I'd rather not use those.

For those that don't know I'm running methanol injection for knock suppression which I'm sure can factor into this decision.


i ran tr6's on my truck. i swapped plugs regularly. changed to the r42's and didnt like them, my truck was hard starting. swapped to tr5's with no issues at 20+ psi. dont think it matters much on a not so serious truck. if your truck runs and starts fine with a tr6 or r43 then run them, if just for the peace of mind :D

[Zygoat]

you can check your current ones for fouling.

[rentedmule]

Thanks for the input 94s10. I am going to check the plugs obviously but on my engine that requires taking off all the charge tubing. Not a hard job but it's annoying so if they're bad I'd like to have the new plugs on hand so I don't have to do it twice.

I checked yesterday and I would have had to order the R43LTS's but I finally managed to track down a set of TR6ix's so I'll try those.

[94s10]

the pass side of my engine bay is wide open, but for the drivers side i pull the inner fender to get to the plugs. i then use a couple of extensions so i can pull the plugs from the outside of the truck lol

just a though

[rentedmule]

Got the new TR6ix's in today and they made a HUGE difference. It's running so much smoother now and I don't get that annoying shake/rattle when it's in gear with my foot on the brake. It was hard to swallow $75 for a set of plugs but they did fix the problem.

The R42's looked dry but they were really chalky and black and the gap had opened up to ~0.045 (they were at 0.035 originally). It's possible that one of the plug wires may not have been clipped on all the way too, it came off way too easy! That could have been the problem all along but the plugs needed to be changed regardless.

[Cameo_S10]

Cool! Good deal man.

[UR50SLO]

The 4.3s don't like much of a plug gap. Anything above 10psi it'll blow the spark out with more that .30 gap.
The vortec heads are better about this but the spark is so weak and the way the chamber is designed it'll blow the spark out.

On our turbo 98 truck I run the R43's with .30 gap.
42's are too cold for daily driving imhop.

Irrid. plugs are the best... but I'd have the tune dead on so your not waisting so much on plugs while tuning.
~Scott

[rentedmule]

Thanks for the info Scott. The truck has been dyno tuned but I ran it for a long time on that same set of plugs without a tune. The S/C crapped out on me a few times as well so I was even running NA with them for a while. The difference with the new plugs was pretty amazing actually, it's running so much smoother now!

[Sleeper S10]

I have a NEW set of NGK Iridium Spark Plugs that I have no more use for as I am swaping for a 5.3.2 Heat ranges colder.Best offer shipped.

[12sws27]

Yes I'm grave digging! So what!

Tyson, From the info I'm getting, the stock heat range is 5 or ngk plugs. The higher the number the colder the plug. Atleast I think. So the TR6's are one heat range colder. I'm confused. You said you wanted a stock heat range. What am I missing?

I'm getting plugs for the Blazer today and was looking for a part number for the iridiums you got. But I guess I have to look for TR5IX or some sh!t like that.

[rentedmule]

I ended up biting the bullet and buying the TR6ix's a while back. The truck is running fine with them N.A. so I'm not going to change back to stock heat range ones. I feel like they may give some safety factor when I'm racing and regularly bouncing off the rev limiter too - that may not be true though!

[12sws27]

I ended up biting the bullet and buying the TR6ix's a while back. The truck is running fine with them N.A. so I'm not going to change back to stock heat range ones. I feel like they may give some safety factor when I'm racing and regularly bouncing off the rev limiter too - that may not be true though!
Oh ok. I thought you were saying the TR6IX's were stock heat range and I was finding TR5's as the replacement plugs and got confused. Autozone didn't have any TR5IX's, TR55IX's or even TR55G's in stock. So I just ended up getting Acdelco 41-993's


That reminds me, I still need to change mine.
Meh, they could probably go another year.

[12sws27]

Just do like I used to do to the Dodge. Pull them out, clean them off, re-gap them and put them fukrs right back in. :D

[LEADFOOT]

Im not boosted. I have the msd 6A and burnt the piss out of the NGK Iridiums, like within less than 12 months. Gap increased alot. I was pissed, I bought them right when they came out and they were expensive as hell. Platinum didnt last either. Then I learned I should be running a regular plug. Also learned it isn't a bad idea to run 1 step colder with the MSD even being NA. So know I use the NGK TR6 regular vpower. I still have to replace them about every 13 months or so but the cost is much better.