what spark plug to use?

[Crazyx4]

stage 2 4.1, ported aluminum champion heads. i have ngk r5671a-8 now. running vp c16 fuel at 23psi of boost. car ran 6.37@108 at an 1/8 track. i would like to up the boost but i don't know if i should use a colded plug. i have the ngk r5671a-10. do i need to go with the colder plug. would like to up the boost to around 30 psi.

 

[forcefed3.8's]

I have been using Autolite AR3932's.

 

[Crazyx4]

i think the ngk r5671a-10 is the cross ref. for the ar3932.

 

[norbs]

Both are non resistor plugs BTW.

 

[Crazyx4]

which plug do you like?

 

[norbs]

The NGk's mentioned are fine but the -10 is a little bit too cold, are you running into issues with the 8? The non-resistor plugs will give you the most spark energy, at the trade off of plug life with a high powered ignition, but if your change them all the time it won;t be a problem.

 

[jpwalt1987]

I run Autolite 3922s gapped at .30

 

[Crazyx4]

no problems yet. first time out with the car. going to up the boost and didn't know if the 8's would be ok. just wanted to be on the safe side.

 

[J-B Racing]

the 8's are good. You can try the 9. Stick with NGK..I find they are hard to beat..