[Epx998]

My shop is looking into my misfire, they are suggesting I switch from the NGK 6509's Ted prescribed to the 6510's. They build a lot of LS boosted motors and these are the plugs they use. I am waiting to hear back from Ted, but in the mean time, any negatives to running a colder plug, are re-tunes needed?

[laynlo15]

I actually just run the LT4 plugs instead of the NGK.

[Epx998]

Originally Posted by laynlo15

I actually just run the LT4 plugs instead of the NGK.

How different are the LT4 plugs from the 6510's? I have another set of 6509's from Ted that I bought to help trouble-shoot the misfire. The shop is adamant on the 6510's though for boosted LS motors. Jannetty has paired a lot of LS motors with 6510's previous, per Kris, but on the LT's he's using 6509's. Sort of wondering why one vs the other.

[KingLT1]

6509 is a LTR6IX iridium. It's a 6 heat range.

6510 is a LTR7IX iridium. It's a 7 heat range.


Heat range is the biggest factor here. The colder plug will foul easier with a lot of low rpm street driving. But it shouldn't be misfiring with very little use or mileage. They will need changed more often is all. I am running 6510's in mine right now being that is what Whipple recommends. I would check the plugs for cracks in the porcelain ….I would suspect that is the issue. A 7 heat range shouldn't misfire with low mileage imo. I suspect Ted uses a 6 heat range for cars that are daily driven opposed to a weekend warrior. With proper tuning it probably can be done with proper timing and fueling adjustments.

[Epx998]

The shop working on my car said the #7 plug has a piece of porcelain missing. I haven't seen it yet, the shop should be sending me a photo. The car was daily driven, less so now. So if I switch to the 6510's I would need a re-tune from Ted?

Originally Posted by KingLT1

6509 is a LTR6IX iridium. It's a 6 heat range.

6510 is a LTR7IX iridium. It's a 7 heat range.


Heat range is the biggest factor here. The colder plug will foul easier with a lot of low rpm street driving. But it shouldn't be misfiring with very little use or mileage. They will need changed more often is all. I am running 6510's in mine right now being that is what Whipple recommends. I would check the plugs for cracks in the porcelain ….I would suspect that is the issue. A 7 heat range shouldn't misfire with low mileage imo. I suspect Ted uses a 6 heat range for cars that are daily driven opposed to a weekend warrior. With proper tuning it probably can be done with proper timing and fueling adjustments.

[KingLT1]

No you shouldn't need a retune if it is already tuned on the 6 heat range. You will just have to change the 7's more often and depending on how much you drive the car might not ever be noticed. Just don't expect to go 50-100k miles on plugs. Drive it spiritedly from time to time to keep the plugs clean and it should be fine. If you drive it like Ms. Daisy all the time expect the plugs to load up.

[Epx998]

New plugs are in. Car is beastmode again.

[Drsagacity]

Originally Posted by Epx998

New plugs are in. Car is beastmode again.

Great feeling isn’t it? I did that same thing recently. Dead miss to beast mode in just a second. Now you can finish the tune and get it just the way you want it.

[Epx998]

It is weird because the misfire was under specific conditions, I was able to drive it and not get the misfire by being careful at certain RPMs. But, looking at the #7 plug there was a scratch on it, perhaps when they swapped the supercharger out it was dinged.

The shop also added some BMR goodies that have been waiting since xmas. The ride home was very nice. I have the BAP from Ted, so i'll schedule that and get the tune finished in time for summer.

Quite happy ... today

[laynlo15]

Good to hear.

[TJay74]

Originally Posted by Epx998

It is weird because the misfire was under specific conditions, I was able to drive it and not get the misfire by being careful at certain RPMs. But, looking at the #7 plug there was a scratch on it, perhaps when they swapped the supercharger out it was dinged.

The shop also added some BMR goodies that have been waiting since xmas. The ride home was very nice. I have the BAP from Ted, so i'll schedule that and get the tune finished in time for summer.

Quite happy ... today

Are you doing the install on the BAP? I just installed mine and got the tune finished up last week with Ted.

[Drsagacity]

Originally Posted by TJay74

Are you doing the install on the BAP? I just installed mine and got the tune finished up last week with Ted.

The Voltage booster was a game changer for my car. Can’t wait to hear your thoughts after you get the BaP dialed in.

[Epx998]

The BAP will go on next week or the week after. I just spoke with Ted, we'll pick up where we left off from there.

[TJay74]

Originally Posted by Drsagacity

The Voltage booster was a game changer for my car. Can’t wait to hear your thoughts after you get the BaP dialed in.

Mine is in and setup. I didnt notice a seat of the pants effect, but the logs do show the low side fuel pressure if holding better for sure. Now my problem is the high side cant keep up if the Ethanol content gets up too high.