Take a quick look at these plugs please

[Geoff]

I don't know why you need colder plugs than -5s, the factory heat range. The car is not being circle tracked raced, where the plugs would see continuous high rpm operation...& more heat.

Plus, you have alum heads that remove heat more quickly than iron heads, so you would want a hotter plug to maintain tip temperature within working limits.

[Mike Beck]

Anything with more than stock power usually starts to get a colder plug. My slow ass SBC383 is 10.25:1 and makes about 400hp, it runs mint on NGK -7's. Old ass AFR 195cc aluminum heads. Never ever fouls a plug. What gain is there to running a hot plug? Trying to make-up for a bad tune?

[SBP436]

Originally Posted by Geoff

I don't know why you need colder plugs than -5s, the factory heat range. The car is not being circle tracked raced, where the plugs would see continuous high rpm operation...& more heat.

Plus, you have alum heads that remove heat more quickly than iron heads, so you would want a hotter plug to maintain tip temperature within working limits.

LMAOOOO

[Geoff]

Laugh all you want & show your ignorance.

If you read the OPs post, he ran the same with -5 & -6 plugs. From the description, it is a street car that gets drag raced occasionally. You want the hottest plug the engine will tolerate without causing pre-ign so that the plugs do not load up when idling/cruising.

[Warp Speed]

Originally Posted by Geoff

Laugh all you want & show your ignorance.

If you read the OPs post, he ran the same with -5 & -6 plugs. From the description, it is a street car that gets drag raced occasionally. You want the hottest plug the engine will tolerate without causing pre-ign so that the plugs do not load up when idling/cruising.

Actually, you want the coldest plug that will not allow fouling. That is, unless you have access to a system that can properly test for pre ingnition.

[Mike Beck]

Originally Posted by Warp Speed

Actually, you want the coldest plug that will not allow fouling. That is, unless you have access to a system that can properly test for pre ingnition.

I'm with you!

[CATCRACKER72]

Originally Posted by Mike Beck

Anything with more than stock power usually starts to get a colder plug. My slow ass SBC383 is 10.25:1 and makes about 400hp, it runs mint on NGK -7's. Old ass AFR 195cc aluminum heads. Never ever fouls a plug. What gain is there to running a hot plug? Trying to make-up for a bad tune?

Thats awesome! LMAO.

He wants the hottest plug.. ok there.. maybe in his Prius..

[SBP436]

Originally Posted by Geoff

Laugh all you want & show your ignorance.

If you read the OPs post, he ran the same with -5 & -6 plugs. From the description, it is a street car that gets drag raced occasionally. You want the hottest plug the engine will tolerate without causing pre-ign so that the plugs do not load up when idling/cruising.

LMOOOOOO

[Mike Beck]

Originally Posted by CATCRACKER72

Thats awesome! LMAO.

He wants the hottest plug.. ok there.. maybe in his Prius..

[wingnutks]

Originally Posted by Warp Speed

Actually, you want the coldest plug that will not allow fouling. That is, unless you have access to a system that can properly test for pre ingnition.

This makes the most sense to me. I dont have anyway to detect knock other than plugs so the safer the better.
Also, might be my inexperience showing but on brand new plugs how does a hotter plug make more horsepower? These arent supposed to be glow plugs right? When the plug fires is when the fuel should ignite, so shouldnt it not really matter how cold the plug is as long as it doesnt foul from idling around? Basically shouldnt the car run the same on the track with a -5 plug compared to a -10 plug?