I've heard of people cutting the ground electrode off at the edge of the center electrode as opposed to going across the center electrode. Any comments good or bad? I've got a 79 Z28 359ci about 10.5:1, runs mid 12s. MSD Digital 6+, MSD billet distributor, MSD HVC II coil, MSD wires, Accel plugs .035. Normally Aspirated now going to install Nitrous Express 2 stage plate soon. Would this mod help? Should I increase the gap to say .045?

 

You probably already know that the idea behind this mod is to expose the spark to the mixture better and not impede the progress of the flame front. I suspect it helps about as much as indexing the plugs. The downside is that with a good ignition and cut electrodes, you have to keep an eye on the plug gap because it tends to open up. Add nitrous and you'll really have to check your plugs frequently.

Is this a race car or a street car or both?

 

98% race. With the hot ignition that I have, how long do you think before the gaps open say .002-.003?

 

Ya don't have to cut them,ya can buy them like that..002-.003=5,000 miles if they are not platinum.
DO NOT increase your gap set it at .035 and forget it.

 

To me that means you're serious about racing, which means that you'll probably be pulling plugs now and then to read them, so just check the gap when you're doing that.

 

I use NGK race plugs. Local Napa carries them and they cost the same as normal spark plugs. Gap them, index so the electrode doesn't get hit by the piston and install them. I don't need fancy platinum, split electrode, multiple electrode etc plugs. They're not worth the extra money for a race engine. I do use platinum plugs in my daily driver because it's so hard to change plugs.

If you start to try modifying the plugs, don't expect to see any gains if any. It's possible you may see 1-2 hp on a dyno depending on what you do to the plug. You will probably see better performance by just adjusting the gap until you find the best gap for the engine.