Which plug and gap for msd?
 

I am planning to install an msd 6al in my 930 with the usual bolt on stuff running at .9 bar. After searching the forum I am still confused. I was thinking of running the w4cs with .35 gap. Is this too hot with the msd or should I go for a non-platinum 3 heat range? Any help appreciated. (street only car)

Those are the same plugs I'm running with MSD 6AL and 8762 MSD boost retard and I have them gapped @ .040"

Works great all the time and they are not too hot to cause detonation on 91 octane at 1-1.05 bar.

Since its a street car, start at .035 and work your way out until it misses or idles rough. Then close it .002 or .003 and see how it does.

.35 might be a bit too ambitious even for an MSD....

I run .040 with MSD as well...but using an NGK racing plug in their "8" heat range. Lots of spark energy behind the MSD and blaster coil. Have run up to 1.0 bar boost with no missing. Seems they (MSD) spec something like .050...wow, a bit much I would say for a boosted car.

Thanks for the info, guys!

And if you do run .040" or larger, make sure your cap, rotor and wires are in good shape and can handle the load. The spark will always find the weakest point, or more precisely the most direct path.