well after searching i read in a few threads that higher compression ratio's needed colder plugs. just trying to verify this, any help is appreciated.

 

yep

 

I'm running one range colder Iridiums

 

so if my usdm h22a1 has a compression reading of 210 should i look into colder plugs?

 

You misunderstand. One should run colder plugs if one has raised the compression ratio, such as by running higher compression pistons, or a thinner head gasket.

Your compression reading of 210 psi from a compression check is not your compression ratio. And incidently, 210 psi is typical for a USDM motor with stock 10:1 compression ratio.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sharkcohen &raquo;</TD></TR><TR><TD CLASS="quote">You misunderstand. One should run colder plugs if one has raised the compression ratio, such as by running higher compression pistons, or a thinner head gasket.

Your compression reading of 210 psi from a compression check is not your compression ratio. And incidently, 210 psi is typical for a USDM motor with stock 10:1 compression ratio.</TD></TR></TABLE>

thanks, i was under the impression that 185 psi was stock and anything more meant there was carbon build up. thus the built up carbon raised the compression ratio. on me.

 

Well, 185 psi is what is considered "nominal" according to the Helm, but 210 seems to be around what people usually get. It's nothing to be concerned about and it certainly doesn't warrant a colder plug.

 

Hmmn I think i have been using regular plugs for the longest. Is there really that much of a difference going on colder?!?

 

i was reading the honda manual and 160 to 190 is considered normal compression......

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jason kiDD &raquo;</TD></TR><TR><TD CLASS="quote">Hmmn I think i have been using regular plugs for the longest. Is there really that much of a difference going on colder?!?</TD></TR></TABLE>

i would like to know as well, over a years ago when i did my swap in the first place. I asked in here and in the hybrid forums and everyone came back saying that you dont need colder plugs unless you are going to be boosting. So since then i have always just used stock

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94vtirozguy &raquo;</TD></TR><TR><TD CLASS="quote">i was reading the honda manual and 160 to 190 is considered normal compression...... </TD></TR></TABLE>

Mine checked in at 185psi on all 4. Thats with 180,000km or 111,000miles.

I don't understand how ppl get more than 20psi above nominal??

 

one colder plug I Guess, is playing it safe. Very generally, If there's no detonation. there's no problem. A stock heat range plug should be just fine. (Depending on just how much higher you go)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxlr8 &raquo;</TD></TR><TR><TD CLASS="quote">Very generally, If there's no detonation. there's no problem.</TD></TR></TABLE>^Yep, what he said.

 

How bout type-s pistons spinning to 8000 rpm? Would I benefit?

 

sorry to bring this thread back up but for the ngk iridiumIX what would be the part number for a heat range lower and 2 heat ranges