I played with my Mega Gs alot this week,set them up as box stocks.
.350" fronts and .422" rears gave the best performance but the cars
are closer in lap times to open wheel Tyco X2s than open wheel
Super Gs.If you take all three brands,keep the stock front tires,
put .450" rears on them all,and race them on 12 volts ,they are fun
and all turn about the same lap times.But as an all out killer box stock
they fall short.Best to run them against other Mega Gs or as stated
above on 12 volts.The bodies would last longer on the lower voltage
crashes also.

I also found .422 Tyco size Super tires to be the best size. As far as the front. When I dropped it to just .352 it started stalling, in other words, the front shoes would need to be flatten.

Tim--- did you flip the tration magnet to High DF position?

Flip the magnet??? Can you explain please??? ...RM

Flipping the magnet would orient the magnet so that
the traction magnets would work together.If you match
them to the motor magnets you can get a little more
strength.Tomy should have done this at the factory,under
our and HOPRA rules,magnet orientation has to remain
stock.
If you use the Kelly Green BSRT slip on sils the car has
.450" rear tires.With the stock fronts tires,on 12 volts,
the car has similar lap times and driving characteristics
to a G-jet.A very pleasant setup to race.

Would of been nice if the motor magnets were flush with the bottom of the chassis.

It is surly different than I would have done it.But
it still seems to be a quality piece,not like those
lumps of plastic from the other guys.

I Really Like the way it snaps together very simple & clean. Seems to be strong enough too after 1000laps+ with body or not, NO Damage except the front wing.I aready Modified it so no stock class for ME.......

Now someone needs to make some level 50 traction
magnets, notched to be flush with the bottom of the chassis.
Any rewound arms that are still laying around for the original
G+ should drop right in.

Don't know about level 50, but I would bet BSRT are working on something along those exact lines, and arms too.

For what it is worth, these are not flush, but I think they will fit:

http://www.kjmagnetics.com/proddetail.asp?prod=AFX

Incidentally there is already a tuning thread for the MG in the Slot Car Modeling/Customizing section so can this thread and that one be merged?