It's very common for people on this forum to run the above boost settings, which i currently run... that's why i think i'd get some answers on what spark plugs to use with such boost...

I currently have the originals, thinking of installing the same ones but with one level colder (8 instead of 7)


What SP do u guys use???


Rgds+

 

You may get away with properly gapped 7's. But 8 is always a good choice for higher boost. That's what i run.

 

Are there coppers available for the 9 yet?

 

stock plugs

 

ZOMG you didnt just say coppers did you?

Sorry I tend to be opinionated about things like this, but stock iridiums (gap wil vary depending on application) are the way to go.

 

im running your boost 24-25 peak, 19-20 redline, i use stock plugs, no problems.
I say if you raise boost to 30 then ya you better get colder ones.
you can try it out with 24 boost and let the car idle for a long time, pull the plugs anc check to make sure they are ok.

 

Haha yeah i would run them but i cant keep up with what plugs are out there for the IX. At 12k miles i am not incredibly concerned.

 

Stock iridiums constantly fouled under high boost and alcohol with me. Since I've run copper plugs with a 8 heat range with much better success. If I was sticking with close to stock boost levels I'd probably run the platinums cause you get so much more life outta them, they just did'nt work well with my set up.

 

8 and 9 have completely different plugs

 

I have exceeded 33psi on C16 several times with a Green and Cams and never fouled plugs. I have had spark blow out/misfires but the plugs always looked good. Dont get me wrong I am sure that you did have those problems, but on my IX that hasnt been an issue.

However I have also had problems with coppers on VIII's that I have tuned, Hondas I have tuned, etc. Where I will get misfires as well at even moderate boost. On one VIII in particular I squeezed an extra degree or 2 out of the timing (Consistently) with stock iridiums versus the colder heat range NGK's that had been in the car. Maybe it was just a coincidence...i dont know.

JB

 

what would a proper gap be for my boost??

 

.024 or so...whatever they come at out of the box in my opinion.

 

ngk bpr8es or 3923. i run these and they work great (20g, 32psi, 1200cc's meth)

they are pregapped around .028, I run them around .024-.026. They dont foul/blow out me or any evo's I tuned locally

 

It's for a 9 though. I think 25 psi wont missfire stock plugs and gap, if so just close it, wont hurt at all.

BTW didn't mean to bastardize your wga spring mod, just found out you had already invented it . As ugly as it is, works remarkable - eh?

 

oh my bad yeah x2 on the stockers for IX's.

yeah its an ugly mod but works LOL , probably one of the oldest tricks