Nope the higher the number the colder. Like NA cars will have 5-6 heat range.

 

BPR8ES gap .22 ...better for meth injected vehicles

 

does a smaller gap give bigger/stronger spark? or does a bigger?

 

The projected tip (the correct term for the "p") is too much of a liability in my humble opinion. On the DSMs I had several motor failures which all started when the side electrode burned off the plug and then took out the piston/head/etc. Knock may have played a role, but there were a couple failures that happened at very conservative AFRs and timing, and extreme heat was obviously present in all cases.

Fast forward to the EVO, and the first time trying nitrous on for size. I was nervous about the plugs coming apart, so I went to the non-projected plugs. The shorter side electrode does a much better job of transfering heat to the body of the plug where it can be removed from the plug, and runs cooler. Sounds like something I could use. I started with BR8ES.

I had a couple runs early on where I wasn't paying enough attention to bottle pressure, and I made FULL drag passes in the high 11s at 13.0-13.5:1 AFR, and over 20 degrees of timing, and the plugs looked like I was out for some sunday driving. I am almost certain that if I was on regular 7 plugs like I used to run on this car and the DSM I would have lost an electrode. I eventually started having cold idle issues after 1-2k miles and switch to BR7ES. I believe that in my case the non-projected tip does much more to help keep the plug together than the colder heat range does. The BR7ES plugs last much longer, I change them every other oil change (equals 5k miles). They seem to work just as well with normal nitrous usage, but I have yet to go super lean with the nitrous. I have run 13:1 at 20+ degrees of timing without the nitrous however, with the line pulled off the WGA, and the BR7s looked fine.

YMMV.

 

Are these iridium plugs?

 

The plugs they are discussing are not Iridiums.

 

Do we need to adjust the Gap of NGK Iridium plugs?

 

^No they come pre gapped if you gap them you'll mess up the irridium tip

I use BPR7ES gapped to 0.026 never had a problem and never will

 

so. stock engine. stock boost. tuned to 11.4:1.

it sounds like i want the 8 for fuel economy reasons. i do an occasional track day (buttonwillow) which would produce some heat.. but, as i said, all is stock.

if i were boosting more or using N2O, i would go with the 7 (always one step colder while using nitrous on my old car).

does that all sound about right? go with the BR and, basically, split the difference in heat between the 7 and 8.


????

 

p.s: old thread, i know. but i was curious.

i've had a HELL of a time finding the right plug for my car.

 

i ran the NGK with the longer tip in my honda before boost way back in the day. Taking it to 8800 rpms burnt 2 of them up at the same time (sounded like a subie all the way home) Not sure if can be realted to a boosted engine such as the evo but i know i never use those again.