Spark plugs (
 

I bought some NGK IX Iridiums (9, for those who cant interpret roman numerals) for my boosted engine. Im going to regap them to .28-.30. Anyways my question is, does anyone know what stage prelude spark plugs are stock (I think they are around 5-6?!?. I have the f22a1) . Not the size. I know its supposed to be a step or two colder than stock for boosted applications, so I heard the NGK IX iridiums were good.? Thanks

Re: Spark plugs (
 

not sure about the preludes in specific, but they are probably the same stage or whatever as d and b series, which i'm pretty sure are 6

Re: Spark plugs (
 

Prelude??

Re: Spark plugs (
 

www.ngk.com has a nifty online applet for determining plug whatnot.

9's are used by 500+ whp RSX guys. You think you need them?

Re: Spark plugs (
 

Well my friend used them in his built b18 w/turbo. ran good. couple steps colder to.

Re: Spark plugs (
 

Iridiums scare me with that tiny point. Looks so hotspot prone. I don't like running them in the built K's, but everyone is doing it ::)

You, young sir, are also several orders of magnitude away from a built B-series, beginning with your stock engine... working your way to the Eclipse manifold attached to said engine... and finishing with the tiny ass puling 14B attached to said manifold.

Try a step colder than stock. ZFR6F-11, NGK stock number 4291.

Re: Spark plugs (
 

Also:

https://www.homemadeturbo.com/forum/...?topic=53966.0

It's not anything you need to worry about, but it is food for thought, and will help develop perspective.

Re: Spark plugs (
 

brought back from the dead, I was using ngk bk7re and I could not get my egt to stay stable, then I switch to ngk-4554 in the 8 range and the car ran way better, my friend tried some 9's and his ran way better than with the 7's also.

Re: Spark plugs (
 

Try some 7173's instead of those 4554. It's almost the exact same plug, but the center electrode isn't as recessed. Only the super high CR guys need R5671's with the recessed electrodes because they stand a chance of smacking piston dome into ground strap, whereas the stock or lower CR turbo guys can run the R5672's... whose electrode doesn't come out as far as a stock plug, anyway.

The Black Car in my basement is running R5672-A10's on pumpgas. :o

Re: Spark plugs (
 

thats the thing I am running pump gas, and I think I have high compression, my head is shaved .040 and block .010 and stock head gasket, 9.0.1 pistons. I did a compression check after I put 500 miles on the motor and it was 190 accross. on my old block and my friend's block its 140. so I am a little scared, because its top end driving here average speeds is 120mph.