I know this is pretty much dead, but I wanted to add something I recently noticed. Over the last couple of weeks I've been experimenting with different brands of fuel and octaine levels.

Running at 94 octaine or above, I almost never see this problem. Running 92 or 93 octaine I ocasionally see part throttle "bucking"; usually when I need to transition from part spool WOT to off the gas quickly. It seems to be easier to induce on 92 octaine than 93 octaine.

After installing a home brew grounding kit, I noticed that the "bucking" seems a bit less severe when it does happen. I can't prove that, its just something I think is helping.

Just stuff I noticed and thought I'd share.

 

good input man. I noticed that running higher octane by mixing with race gas smoothed out the upper rpm range from 6-7.5K. On 93 I get a little blip of hesitation at full throttle in the upper rev ranges.