I am having a really hard time looking for 1-Step colder spark plugs for the VQ35HR. Has anyone been able to find a set? I wouldn't feel comfortable spraying without them.

I believe the OEM part number is 22401EW61C.

The only after market plugs I was able to find were the FXE22HR11 from Denso, but they're not colder.

 

Okay here is what I found.

The NGK plug for the HR motor is a 3442 for which the NGK number is R5673-9. On NGK, the number after the - is the heat range and the larger the number, the colder the plug is. So, you can actually get a R5673-10
http://www.google.com/products?hl=en...-revision&cd=1

 

Definitely don't spray without them. You want to go 1 step colder for every 100hp or so.

Let us know how the nitrous goes!!

 

talk to GTM they should know which ones you need.

 

I think I may have found them: http://www.hrautoparts.com/g35ngk.html

 

I think those are for the DE not the HR but I didn't look specifically.

 

colder retards the timing correct?

 

A colder plug is safer because it lowers the risk of detonation...don't know where the "1 Step colder plug for every 100HP or so" came from, in my case my 400WHP SE-R would need about 3 steps colder plugs (which is not the case) but its a general rule to run atleast 1 step colder when detonation could be a problem.

You just need to worry about the thread size and resistance type (and obviously heat). Other than that, there isn't much about being vehicle/motor specific. I'm sure the plugs that fit/work on the HR motor is on a ton load of other cars/motors as well.

 

snowcross,, your joking right?? do colder heat range plugs change are snowmobile engines timing??? heck no!!!!!

 

Obviously you have to read the plugs to see if they're too hot, too cold, or just right. The 1 step is a general rule of thumb.

Here's the info from NGK's website:
http://www.ngksparkplugs.com/tech_su...d.asp?mode=nml

"Typically, for every 75-100 hp you add, you should go one step colder on the spark plug's heat range."

 

actually it does, depends on how much compression you are running, type of fuel



here let me google it for you

http://www.ronlund.com/shim.htm
http://en.wikibooks.org/wiki/Reading...ugs_for_racing
http://www.innovatemotorsports.com/f...hp/t-1036.html

 

I'm sorry but I failed to find anything in those links you provided about how changing to a colder plug will directly retard your timing. Your timing is not set by the heat range of plug you run. If I set my timing at 15 degrees, it will be 15 degrees whether I go colder or not. In those links they're stating that changing to a colder plug WHILE lowering your timing will reduce the risk of detonating.

Back to the subject, 1 step colder should be fine for Nitrous.

 

yessssss paul .. i cant wait to see it done ..
did you get in touch with z-medic??

 

Maybe I was confusing with my statement. Like you said timeing can't "directly" be changed by plug teps. But changing the temp of your plug will have the same net effect as a timeing change of +- 1 or 2 deg if you are having a problem with pinging.

It's like fine tuneing it
Would u agree?

 

Good idea going one step colder