Dusting off a AE TC3 gearing with brushless?
 

Hey RCTech!

I recently got back into the hobby with an Arrma Big Rock. That got me digging around and I found my old TC3, blindly bought a brushless motor and a 2S lipo. Need some help with the gearing.

What I have for the TC3 is a Hobbywing 3652 G2 5400kv motor and ESC combo. The gearing in the car is 24/72 pinion/spur. From what I've read the FDR is 7.5 with this setup. I plan to do some drifting and bashing on concrete with plastic and rubber tires respectively.

Should I be changing the pinion or is this setup ok?

That's a pretty high KV motor to be sticking into a TC3, the drivetrain might take a beating. That FDR should be okay to start with, but I'd guess you'll want to be closer to 6.5.

I'm sure the hobby shop kid was used to people wanting the most power.
Lower FDR= faster top end and higher temps, correct?

I race my TC3 in on-road races and set my FDR to 3.8 as a start and adjust from there. I used sensored brushless motors from 25.5 to 17.5 but have never used the motor you've mentioned. For drifting, you might want the higher FDR to keep the tires spinning so have a go and see how things work out.

Upon further inspection, the pinion is a 26T so I that is a 6.92 ratio, I think I need to go to a 20-22. Would it be ok to run at 6.92 without burning up the motor or ESC?

I think it'll be fine, but check your temps regularly at first to make sure.

Just run it how you have it setup for a couple of minutes and then check the temp of the motor and esc.

I'm about to dust off my old TC3 and Street Weapon and get them ready for carpet racing. The Street Weapon is going to take some work to adapt.

my two favorite on-roaders ever - please show us pix!

Thanks for the help! I've got it all buttoned up, just waiting for a day off to give it a go!

Sounds good. I'll get the before pictures now and take more when they are all setup.

Let us know how the rear diff did on carpet...Carpet is supertough on the diff...

I probably won't be running any carpet, but if I do I'll report back.

From my experience, everything with more power than a 13.5 blinky will destroy the diff in no time...

Getting the diff to lock on acceleration, even with a 21.5t, is the real issue...The slipping on black carpet is terrible. I heard steel balls will have more bite than ceramics or carbide, but they will not last as long...I am still experimenting to find a good solution, but the diff bolt keeps snapping with a 4.5t on black carpet...The key is to find enough friction to lock the diff gear ring and the outdrives when power is applied, without much diff spring tension....I will be moving up to 3.5t on crc black carpet to experiment some more....