Ok. I've done more research and answered just about every question I had. I found out that the stock plugs are NGK IGR7A-G. They have a heat range of 7 and are supposed to have a gap of .028"/.8mm (but it usually is less from the factory) and are Iridium. The copper NGKs (with a stock heat range) are BPR7ES. The UPGRADED Iridium plugs (thats where I got confused cause everyone talked about stock Iridium NGK plugs but they aren't the good high performance ones) are the NGK IridiumIX plugs. Now here is where I'm still a little confused. I'm pretty sure the right plug model is the BPR7EIX plug (this is according to ngksparkplugs.com; so I think I'll trust them. lol). Where my confusion comes in is that I was looking for them cheap online and I just happened to look at vividracing and they have the stock heat plug listed at BPR6EIX and the one step colder as BPR7EIX. Which is right? I'm pretty sure the vivid site is wrong. I just want to make sure. I wasn't planning on ordering from them anyways. I found the BPR7EIX's from rockauto.com for 24.88 for 4 (6.22 a piece) and that seems like a deal. Still gotta check shipping though. Thanks.

 

FYI, JSC Speed shows the BPR6EIX as the stock plugs also.

http://www.jscspeed.com/evo/engine/ngk.htm

They are $7 a pop and shipping runs roughly $9. Why are you looking to get the NGK Iridium's if you don't think they are good ones? I am debating on which ones to get myself. LancerShop has the stock plugs for $12.95 (4) and today, the Mitsu dealer told me $28 a pop. I hope he meant $28 for all 4, but he said a piece and I didn't want to challenge the poor guy anymore...

 

yep they are about 25 to 28 a pc at the dealer...they can go on and keep that!! I run the copper NGK BPR7ES with a .26 gap with no problems, just change them out more frequently for the hell of it and at 2.25 a pc no biggie.

 

Where do you get yours Evoego? $2.25 a piece is a good price.

 

at what point should you go 1 colder?

 

I think you took that wrong. I meant the NGK Iridiums that come in the care are a lower performance than the NGK IridiumIX plugs. I want the IridiumIX plugs since they are better than stock. I never said NGK Iridiums weren't good. I just want the right part number since I don't need a step colder yet.



I hate to tell you but I do believe he meant $28 a piece. I was reading on another thread that a dealer wanted 130 for 4 plugs. A total rip off.



when you are in the 350-400 crank horsepower range. at least thats what i've seen during my readings.

 

Buy your plugs from here:
http://www.sparkplugs.com/results_cross.asp?pid=IGR7A-G

Also, get the Denso IW01-24 They're the best you can buy

 

Are those the stock heat range?

 

The IGR7A-G is the stock plug that comes with the car, so yes it is the stock heat range.

As for the Denso IW01-24, it is a full racing plug and is 1 heat range colder than stock.

Denso 22 = NGK 7
Denso 24 = NGK 8

 

Stock heat range on the Evo is 7. I believe on the older 4g63's like the DSM it was 6 hence where they got that info from. I chose to go with 8's on a stock setup, and they work Fantastic. I get a smoooth rev all the way to redline.. and it safer on the higher boosting in general. I have BPR8ES, $2.25 a piece, change them out every 15k or so.. Gapped at .028 So if you want to go with the Iridium go with 8's.. Youll be much happier, plus ive had this confirmed by some of the fastest evo pro tuner guys, and people who really have experience in the field.. Just my opinion though..