I was told that with a bigger turbo(20g9) and higher boost(mostly25,up to30) to go colder, then with meth which cools, not to go to cold.
So I'm 1/2 step colder then stock with BR7ES @26-28. You guys agree?

 

8 is good enough

 

Since it seems not to have been stated the IX uses stock part number ILFR7H. And after talking with a tech at NGK today they (as of now) do not have any 8 heat range plugs with the exception of racing plugs. The downside to this is the racing plugs cost is really high. That part number for those interested is R7437-8.

The reason the evo nine has model specific plugs is they use a longer threaded section. Also the factory gap is different that previous models. The IX gap reccomendation is .02-.023.

 

Ngk Br-8-es

 

I guess I should put in my 2 cents. Yes, you do need to gap iridium plugs. They do not come pre-gapped no matter who tells you that. I have installed a bazillion of these plugs and they are never the same gap. What you have to do is use a feeler gauge. If the gap is too big, tap the plug on something to close the gap. Don't hit is too hard obviously. If the gap is too small, you need to use a pair of needle nose pliers and grab the end and pull it away from the electrode. It's a little time consuming, but it's better than installing the plugs without gapping them and wondering why your car runs like shiot.

 

With everything in my signature which Iridium plugs should I get? I think the BPR7EIX but Im not sure. Its that or the 8s but I think it might be to cold. Im running 21-22psi on 93. I should be putting down around 330 to the wheels on the AMS dyno.

 

peter at ISP told me to gap my plugs at 22 there BPR7ES and i have a RNR GT3076 turbo kit with a .63 hotside swap at 22 psi

 

What is most interesting in my research is the fact there are many plugs for the EVO8 but hardly any for the EVO9. I know it has been discussed that the EVO8 plugs will fit the EVO9 but I am not comfortable with that solution. One main thing is the reach of the spark plug for the EVO9 is considerably longer (it is called long reach). I tried using the EVO8 plugs myself and the spark plug boots did not fit/go all the way down. I am interested in trying 8&9 temps. I plan on calling NGK and Denso first thing tomorrow.

 

Hmm, well here's one for you. Just went to the stealership today to get plugs because i had a credit there from before, and they gave me IFR6B-K plugs for my 9. I haven't changed my plugs before for side by side looks, but they are longer then normal. But i've never seen this part number anywhere on evom.....

 

Thats interesting and they seem to be a step hotter than the standard plug (7). Those seem to be a 6. Also as listed on NGK.com they are a 3/4 reach like the BR8ES instead of the 26.5mm that is supposed to be used on the EVO9

 

My final conclusion after talking with NGK is:

EVO 8/9 Plugs are very different and should not be interchanged

EVO8 can use 3/4" Reach:
Stock: IGR7A-G (7) /11$ea.
NGK BPR8ES (8) /2.24$ ea.

EVO9 can use 26.5mm Reach:
Stock: ILR7H (7) /11$ea.
Denso IKH24 (8) /11$ ea.
NGK R7437-8 (8) /44$ for 4 (11$ ea.) Sourcing better pricing at the moment
NGK R7438-8 (8) /44$ for 4 (11$ ea.) Sourcing better pricing at the moment

Evo8 Plug on left/ Evo9 on right

 

^thanks

 

Very intresting cssaddictm4 , thanks

 

ya i always thought you were supposed to run BPR8EIX's with that psi?

 

the EVO IX plugs are exactly 7mm longer than the EVO VIII. i'm using the NGK BPR7ES plugs in my VIII bcuz i run 25+PSI on racegas 24/7...