got a quick question just sent of my turbo for a rebuild. I pulled the plugs out and they seem to be in good shape. I have ngk iridium r7420-11 got them from gotham racing and the car was tuned on them. Is there any other plug that i can get for cheaper or should i stick with these and how long should i run these plugs for before changing them?

 

It depends on how much boost you are running and what kind of power you are making, fuel etc...
I run 9's leading, 10.5 trailing on 21 lbs boost on 110 gas
I run 10.5's all way around when running more than that on C16
9's all around are fine for 480-500whp

 

greg has a pretty good guide above... i was told by a special someone to run 10.5's all around for 400 whp+. i wouldnt suggest driving on them all the time they are prone to foul out easily. i couldnt start my new motor on the 10.5's i ran to the autozone and got the normal 7's and 9's and im driving on them right now no problems. i havent put the 10.5's back in to see if i can start up. im going to save them for the dyno day.

 

I have been running NGK B11EGV's all around for a few years. I have a half bridge running 22+lbs on pump/AI and have no cold starting problems, even in winter. They are a snowmobile plug and are around $4/each. You will need to buy a thin walled socket.

 

^ wow 4 bucks!!! should i go to an artic cat dealer???

 

sparkplugs.com carries them, search by part# I run B11EGV's without any problems just like above