IF you got the $$$, a Torq-a-Verter works great. Even with the stock gearing, you'll have about 2.5 times the staring-off torque at the rear axle, and if the power permits, you'll get a slight overdrive of .9>1.
Lets say for G&S that your kart has 12" dia. rear wheels, a 12T clutch and a 60T rear sprocket, and that you're running #35 chain.......
Stall/Slip RPM on the clutch is 2200 rpm (typical)
Max governed RPM 3600.
Stock kart W/O the TC......
Stall speed: (when the clutch finally stops slipping) is around 16 mph. (Sound about right? You can kinda "tell" when the cent/clutch hooks up by the acceleration change)
Max governed speed: (assuming NO engine mods) 26 mph.
Rear-wheel torque at the tread/ground interface: 120 ft.lbs. (at about 20 mph.... lower when you start out.)
I had no "Gawd-Awful" failures with my stock clone up to 4500 rpm, so assuming you try the remove-the-governer thing, you'll get 32 mph out of it.
Now- lets assume you do nothing else but fit a Torq-a-verter on it.
Stall Speed (When belt stops slipping but converter is still in lowest ratio) ...6mph! Your motor hooks up and reaches almost it's max torque at only 6 mph, instead of 16mph! MUCH better starting off power!
Max governed speed (again, only if the conditions permit) 29 mph. Not a huge gain, but remember; you didn't mod the motor at all, and you've upped your top speed by 10%, and....
Rear-wheel torque at the tread/ground interface: 300 ft.lbs! vs, 120 ft lbs stock. If you have a live axle set up, you can darned near climb trees.
I did a simular bit with my Manco.....
13" dia wheels, live axle, stock clone.
The old ratio was 6>1 with a clutch. Pretty torquey, but top speed was limited to 20 mph.
With the torque converter, a change to a 4>1 ratio, and the stock clone 6.5, it'll hit 38mph tops, and it climbs just about anything and takes off quickly. (The motor could use a few fun mods, but right now, it's stock)
I highly recommend it.
