Just as a reminder, 32-pitch and 48-pitch aren't compatible.
I did this already
So I just got my 76T spur gear and the 20T pinion that I bought does not reach the spur gear. I suppose I can modify the motor mount hole to allow it to get closer, but in the meantime I am using the 86T spur with the 23T pinion. I believe the ratio is pretty similar, but I'll try that first so I don't have to cut out new mount holes for the motor. Does anyone actually do that? Or is that an indication that you're doing something you shouldn't?
The 23/86 is gonna get you up to around 55mph on 3S. So you're still good! You can also go with a larger pinion on the 76T to fill in the gap without having to modify the case. You're going to be moving into 70MPH territory with anything larger than a 26T pinion.
Thanks for the info and the chart! Hopefully my spur gear holds up, the one I found is the official Traxxas 76T and it seems to be plastic. We'll see!
As long as you mesh the spur and pinion properly you shouldn't have any issues. This is still relatively close to the VXL3S system, but way more efficient because of the 120amp ESC and higher RPM motor.
So this brushless system is amazing, but being a 2WD it literally takes off and does a backflip even gently accelerating up to speed. There's not enough down force on the front of the car I think, and it ends up acting like a wing. I do have the monster tires on it, so maybe I'll try going back down to stock to see if the lower ground clearance helps. Or possibly dropping the front end with some tweaking of the shocks?
Just ziptie some large sockets to the front.
The smaller wheels and lower COG will help. You can also add weight to the front like @Chubaka suggested. Turning down the punch on the ESC can help. You could also loosen the slipper a 1/4 turn.
