I was wondering what is the best spark plug to get for a supercharged car at 10psi. The ones I have now are crap to the 10th power. They are bosch 4 ground straps and I am loosing so much power from them not being able to handle that boost, because the are for one Bosch and 2 you can't gap them. So I was wondering if anyone has had any expierence with different plugs and gains they have seen from them. Any input would be great.

 

I've always heard the old copper plugs are the best conductors for the price but they don't last very long.

 

Autolite HT0. http://www.brenspeed.com/mustang_2005/images/ht0.gif

 

Doesn't really look like you could gap those tho.

 

+1 on the Autolite. No you don't gap them. Also, they need to be a degree cooler than your stock plugs. (for a KB s/c setup at least) I just changed mine after 13000 miles and they were fine, except for the issue of corrosion around the threads that is inherent to the s197. I'll keep changing them every 12000 or so miles to avoid having them sieze up.

 

you can get a tool from a few different places to gap them. PMPMMR

 

These are the only style plugs foir this car - two temps available HT0 and HT1
What are you running other than this style plug and why?

 

Interesting you're running something other than the autolites, thought they were the only right matches?

 

Maybe that's why his aren't performing well. You can gap the autolites. The HTO that came with my whipple were gapped to a little less than .034

 

We need to see a picture of these bosch pugs, next to a stock plug would be great. How about just a part number so I can look them up?