Currently we have 7 leading, and 9 trailing in our stock RX-8s. Has anyone put 9's in the leading? The depth of the plugs seem different so I was just wondering if anyone has had problems or seen damagae with using the 9s where the 7s were.

Now that i'm running boost i'd like to put colder plugs. Thanks for the help.

-hS

 

I think they are different depths. I am running the Denso Iridium plugs. They are the only colder plugs I could find. $37/per is a pretty price though...

 

Thanks MadDog...

Anyone else doing this as well?

 

I had the 8's originally. Worked like a charm. Seemed identical to the 7's. Canzoomer sells them. Now I am on Denso's trailing & leading.

 

Greddy racing plugs here, RE10
I know, very cold plugs, but it works smoothly. have them on for 10k miles now... it cranks better than stock too...

 

very good topic. i've been mulling over the question of which plugs to go with, as well. appreciate all the feedback from those with aftermarket plugs.

dd sends...

 

anyone pulled their cold plugs to check the fouling situation yet?

-MD

 

I use NGK 10.5

Manuel

 

I checked with NGK about two months ago. I knew Manuel was running them, but apparently we can't get them in the states. They had no part number for the US, but said they would be released here soon.

-MD

 

NGK part no R6725-105

I was thinking that any one can buy this sparks on the states............because usually the sparks that the distributor sales in PR came from USA. But if you can't find them in the states you can buy them here and send them to the states thru priority mail, UPS, Fed eX, etc. they also sell colder one's.


Manuel

 

What would the benefits be of running colder plugs?

 

Reduce detonation at higher boost levels.