12.01:1 compression. TR55's or TR6's.
 

Like above says. I am running the TR55's right now with no detonation. But doing some reading it looks like I should be running the TR6's. I thought the 6's were for boost and nitrous. With either plug what should the gap be. I am running .045" right now and have run .035". I just don't want to give any thing up with plugs. So, what plug and what gap?

I'm at 12:1 also, and I run TR6's and so far so good! I have them gapped somewhere between .038 and .040" and again seems to be working fine. I was afraid to go with the TR55 and be too hot of a plug and cause detonation. I figure it is better to be colder and not risk it.

The general rule (including NGKs site) is 1 range lower for each 100hp and gap .004 lower for each 50HP not to exceed .008 from the manufacturers gap. Having said that, use what burns right and gives the best power.

Starting from where one on the power level? Stock? This motor should make 550-570rw NA. So what plug would you go with and what gap?

TR6 gapped out of the box will do fine, gap smaller if spraying.

12.0:1 Tr6 .045

Thanks guys. Looks like another trip to Auto Zone.

Lot of guys with hi compression run the tr6, I sell about 3 to 1 tr55 vs TR6

TR6 .040 gap

So you sell more 55's than 6's?

What do you all think of the new ix's? Is there any performance to be gained from them? I don't mind changing plugs every 5,000-8,000 miles so I am not worried about longevity.

What about an 11.3 to 1 motor ? Should see 500-525 at the crank. Thanks in advance

Like the others stated. TR6 @ .040

This was referenced to me? Just wanna be sure i'm makin 50-75 or so less horsepower then some guys here are posting.

Thanks again

I like the TR6 on anything approaching 11:1 compression or more.

Thanks Tony

Yep I sell more 55's than 6's. Most guys go for the expensive plugs for longevity.

In 40 sets of plug sales ony 2 sets of iridium's were ordered