[Kevan]

When I first started racing Slot cars in 2015 all the old timers said the same thing...keep adding weight until lap times deteriorate.

Yeah pretty much what I do, as a last resort I should add, try to make sure I have maximised every other part of the potential first.

If you've finished setting the car up and the only thing left is ballast and it reduces lap time then it's not a final resort.  I don't own a single car that goes better with no ballast...tell a lie, Revoslots   ...then again they ain't flyweights so don't need ballast.