The NGK in that photo is a BPR since it protrudes.

the BR is non-protruding. Non protruding is half a step cooler. so a BPR9EIX is heat range 9 and BR9EIX is a half step even cooler.

Either way you can get them in 7/8/9 (7 is stock)

BR9EIX

http://sparkplugs.com/more_info.asp?AAIA=&pid=2451

BPR9EIX

http://sparkplugs.com/more_info.asp?AAIA=&pid=10034

And remember these are Evo 8 plugs

FYI I've changed from same heat range copper to iridium and back again on the dyno with no power differences. I can see if one plug is breaking up and one isn't, then yes you would get your power back with the plugs that aren't breaking up.

 

The evo 8 plugs are "shorter" than the 9's. The 9 plugs threads are about 1/2 inch longer that go into the combustion chamber. Very important to have the right plugs for the corresponding vehicle or else it can cause phantom knock or real knock, hard starts, poor "gas" mileage, etc. Don't ask me how I know

 

yes and 9's in a 8 will misfire like a sonofa*****.

 

So it sounds like BR9EIX are the best bet if you don't want to change your plugs more often then?!!

 

I run BPR7ES at 28 psi on E85. At .025" they were breaking up. I had to put them down to .020" to get them running clean at 28 psi.

I'm surprised the guys running the Sparktech ignitions are still gapping to .020", have you guys tried larger gaps. Seems like a fancy iginition should be able to run gaps around .030" and get a bigger spark yo.

I might try the iridiums again.

 

Might be worth it to try them and see. I want to see how long mine hold up running the E gapped at .22. Still not a hint of break ups anywhere in the powerband.

 

iridium plugs last MUCH longer with e85, I got tired of having to change them so often with the coppers.

 

BPR7ES gapped at .020. I usually changed them every 1000 miles or so as they would start breaking up after that. Thank god they're only about $2 a piece!

 

BR8ES's gapped to 0.020" with a Sparktec CDI System. On 93 I run the same plugs at 0.026"-0.028".

 

I've been told ILFR7H is what fits the EVO IX. The BR9EIX fit the EVo VIII

 

Have you run anything different? How often are you changing yours? I think im going to go back to iridium's too because changing coppers all the time on e85 is getting a little annoying as well as adding on significantly more to yearly maintenance costs.

 

NGK BR9ES .022 @30-32 psi FPRed 5280ft

They might be a little cool.

No significant knock on boost logged so far. Running a Mishimoto 163deg thermostat, so I'm thinking about 8's to reduce the build up.

Might try the Irridium's to see if the mileage holds up to justify the cost, all else staying equal. That might save on the plug hole thread wear and tear.

 

LFR6A-11 NGK Coppers and can be picked up at your local Napa for about $5 a pop. I have to change mine about every oil change or so when they start breaking up. I am running 35+psi on them with the stock ignition/ECU

I have tried the Iridiums and have found that they last no longer for me. So I personally wouldn't waste the money on them.

Keep in mind I have an Evo IX

 

Mind you, I do have an VIII, so I may be a bit out of touch with the IX...

Are the NGK LFR6A-11 coppers the exact same dimensions as the OEM Iridiums? I didn't think there were any coppers for the IX? Or have I been asleep at the wheel...again?

 

Do the 8's come with Iridiums from the factory, because the 9's do. I figured the factory usually has a fair amount of R&D that goes into this stuff. I have only changed my plugs once- when doing the E85 conversion and messing around with latencies and such. The iridiums can take a lot of abuse, boost, and so on. They are worth the price in my book.