Big Joe wrote:
Ok so finally after about two months of tinkering I got me old tc3 up and running. I put a 72 tooth spur with a 26 tooth pinion and when Ihook the batt up it seems ok but I have not ran it on the track yet.does this sound about right and if not which direction should I go with it.
Thanks for your help and I cannot wait to run on sunday
A TC3 has an internal gear ratio of 2.5. So the FDR with a 72 spur and 26 pinion would be 6.92. That would not be right for the classes we typically run. With a 6.9 FDR, your motor will rev high, but your car won't have much top speed.
Which class is this for? VTA, USGT, or 17.5 TC?
For VTA, you need to be at least 5.0, but you want to get as close to 5.0 as you can get. An FDR of 6.9 would be legal in VTA, but slow. For VTA, use a 36 pinion with a 72 spur. You would need to check to be sure the larger pinion would fit. It don't actually know if it will or not.
For USGT, there is no hard rule on the FDR, but 4.0 is usually a safe starting point for most motors. If it fits, I would start with a 44 pinion and 72 spur.
For 17.5 TC, you could start similar to my recommendations for USGT.
If you want to, you can leave your car geared as is. It will work. It just won't have as much top speed. It is really easy to change the gearing in a TC3 at the track and most of us have plenty of spare pinions in case you need to borrow a larger pinion.