TR7ix or BR7EF
Team Owner
Joined: Nov 2007
Posts: 24,035
Likes: 2,342
From: Gilbert AZ
I only use the IX now. Great results. My current set of 8ix must have 12k miles on them, and zero issues. Will go right back in after next round of mods is done. Pulled them the other day and looked great. That is 3 1/2 mile events on them, 40+ runs, and tons of street miles.
Le Mans Master
Joined: Apr 2013
Posts: 5,376
Likes: 1,118
I only use the IX now. Great results. My current set of 8ix must have 12k miles on them, and zero issues. Will go right back in after next round of mods is done. Pulled them the other day and looked great. That is 3 1/2 mile events on them, 40+ runs, and tons of street miles.
But I keep seeing them still being condemned by diehard old school thinking that dictates a copper non-projected plug. Iridium is far more durable than copper, which is why they can use such a fine wire electrode (Denso uses a .4mm center electrode). I was switched onto Iridium after seeing a report many years ago (in National Dragster, iirc) of a plug test that Duttweiler did on a twin turbo V6 with like 38psi and the only plug that wasn’t breaking down when he cranked the boost up was a Denso fine wire Iridium. If they don’t melt in that kind of application, then I figure they’ll be fine for my junk.
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Verdad Gallardo
Team Owner
Joined: Nov 2007
Posts: 24,035
Likes: 2,342
From: Gilbert AZ
CI GS, saw basically the same thing here. Friend tunes high HP imports that run a ton of boost. Evo would break up at ~35psi with copper plugs. Swapped in iridiums, and ran up to 60psi without issue. 1000+awhp 4 cylinder running 60+psi. No difference in heat range, gap, or anything, just plug material. From then on the extra $30 is well worth it to me. If anyone is modding a vette and is even concerned about a $30 cost difference, they shouldn't be touching their car.
Le Mans Master
Joined: Apr 2011
Posts: 7,821
Likes: 412
From: Montreal
St. Jude Donor '13
Same reason I pay extra for silver.... work great.. last forever, best conductor, and safest as they will melt before get hot enough to cause detonation. Few bucks more doesn't matter at this point.
Melting Slicks
Joined: Jun 2004
Posts: 2,836
Likes: 110
From: El Paso TX.
Burning Brakes
Joined: Jul 2002
Posts: 791
Likes: 52
There's more info in their website including a heat range cross reference chart along with specifics on the plugs. Here is a basic guide.
Projected Tip
- GR14YS - similar to NGK range 7
- GR12YS - similar to NGK heat range 8
Non-projected tip
- GR14S - similar to NGK range 7
- GR12S - similar to NGK heat range 8
https://www.briskracing.com/heat-ran...eference-table
Projected Tip
- GR14YS - similar to NGK range 7
- GR12YS - similar to NGK heat range 8
Non-projected tip
- GR14S - similar to NGK range 7
- GR12S - similar to NGK heat range 8
https://www.briskracing.com/heat-ran...eference-table