I am going with the NGk tr55s, my car is camed with a msd igition and was wondering what the proper gap would be. I was thinking .50 but i am not for sure with the cam and headers.

Thanks guys

 

NGK TR55s work best at .050". I too am running them with my setup.

 

I've never had "best" luck with plags gapped on the "wide" side. I'd classify "wide" as .050-.060.

My best results have come in gapping plugs (no precious metal plugs) from .035-.040. I know a number of guys who've found a few hp here and there with wider gaps when combined with a leaner a/f mixture but the cars always seemed to slow down the track.

Have to keep in mind that errosion will open the gap in time. So, the benefit to going wider just doesn't add up in my mind. Open for experimentation... but all of my experiences lead me to a tighter gap, even with hot ignition systems.

-Mindgame

 

I'm going with Larry's suggestion next time myself.
http://web.camaross.com/forums/showt...30#post2392630

 

so what are the total cons/pros of going stock gap vs. something gapped smaller?
i'm guessing the wide have a better idle of course
which has more total life?
will running colder hurt the engine at all?
i'm doing the plugs when i install my headers (on backorder) so i'm just wondering

 

Like Mindgame said,go with .035 and factory heat range,if you don't have NOS.You will have less ignition problems in the future.
The only thing "wide"gap is good for is a smoother idle and to sell tuneup's ie; wires,opti,plugs.

 

Larry, When do you recommend going to a colder heat range on a NA vehicle?

 

If you are on the verge of or rattling the motor lightly 1-2 steps colder will help sometimes,without pulling timing.The tip design will also help but that subject is a book by itself. In a trailer queen you run the coldest plugs that will stay clean,and hot enough you don't have to change them every pass.It's trial and error when you get to that level and plugs get expensive after a few sets every race day. In a daily driver I would run maybe 1 step colder than factory and that should give you good all around service gapped at .035.