they work however u need a spacer for one of them (L) or (T) but not sure which....I personally think you are better off just running stock rx8 plugs

 

you try taking a pic of a dark hole and see how far you get

 

hehehe

 

The trailing plugs required spacers.
I ran the RX7 plugs for a couple years, but would agree that its better to stick with the stock plugs.

 

I'm currently running stock RX-8 plugs in the trailing, and RX-7 plugs in the leading. I didn't want to fool with a spacer, and possibly screwing something up.

My fuel mileage is the exact same with the -7 leading plugs. I've got no noticeable loss of power. I've been running these for about 4,000 miles, so far, with no noticeable issues/problems.

I'm planning on pulling the plugs at 10k miles to check them out, to satisfy my own curiosity. I'm not expecting to see anything significant/different. And for the cost difference, it's well worth it to me to run the 7 plugs if there's no difference in mileage & carbon build up.

 

So does anyone have a website or source where I can find the 2mm shims? I have been looking for them here in town, and cant find them. I am starting to get misfires whenever i am off the throttle. So if anyone can help me find them I would greatly appreciate it. I went ahead and bought 9's for the "L" and "T" for my turbo application.

 

I have them on my list of things to acquire so I may be able to help soon.

 

try lookin for 2 1mm shims...they basically look like washers that fit on the spark plug

 

hopefully soon.....I would like to put in the new plugs for the MM dyno day in January!

 

what kind of gaps are people running with the stock plugs?
OD

 

Does anyone know where you can get the 2mm (or 1mm) shims for the trailing plug? or would plain washers do the trick?

Would these work? http://www.mcmaster.com/#98089a392/=1jnhf8

 

try lookin at home depot or autozone

 

So just the plain washers work fine, I take it? Just want to be sure they arnt special crush washers or anything


Thanks!

 

well yeah thats what they are, just as long as they fit

 

7 month bumpage...

To Brettus, if you see this, I'd really love to know more about your naked housing and rx7 plug. I ran all trailing rx7 plugs for a while, using two shims for the trailing position. After reading your post, I'm just wondering if the 21mm vs 19mm issue is fact or fiction. No need to waste your time on this thread though, just wondering.

And, NGK part numbers get colder as the number get higher correct? So what is the real reason that rotary leading and trailing heat ranges are off by about two level?