Black smoke between shifts bad?

I let my boy make a pass down the track in my car and I noticed that everytime he shifted a nice puff of black smoke came out the exhaust. It doesnt smoke any other time just full throttle between shifts. I think it is because my car is running too rich.

I think it is because my car is running too rich.

That would also be my assumption.

honda VTECs tend to run extra rich in VTEC so it's normal, but black might not be
My lude puffs a little white smoke, it's extra unburnt fuel, when im WOT and shift form 1-2 in in VTEC

yeah, it's cuz ur running rich. it's normal