Is it possable that a car be under geared and run hot? I know over gearing runs them hot.

Is it possable that a car be under geared and run hot? I know over gearing runs them hot.

Hey Bill, What kind of car?

The car is a xxx4. If the car calls for a 18t pinion and you run a 16t is that over geared or under?

That's under gearing. Dropping two teeth on the pinion from 18 tooth to a 16 tooth is a lot, you have just dropped your drive ratio 13%. Why did you drop the pinion size?
What were you looking to gain?

Are you racing this car or bashing?

Just bashing I was hoping to keep temps dowm but it runs really hot. So I ques Ill put the 18t on and see.

Define bashing.

Are you doing extended high speed runs or are you doing low speed stuff. Lots of hills and such. Doing burnouts or donuts over and over?

If you are doing low speed stuff and not allowing the motor to get some passing air, then you could still be over geared.

All the gearing will not matter in the least is you have a bind somewhere in the car. Check your gear mesh and all the tires/wheels to be sure they are free.

Hope this helps.

All is free as far as drive train goes. I run on a flat ungroomed dirt track 4 40ft straighta and 3 180 degree turns. The xxx4 is sealed well so I am sure that not much air gets in there.

Does it seem as though it is getting to "top out"? If not then you may still be over geared.

What motor/battery combo?

I dont think it could top out on the track. the motor is a 10t Speed Gem Pyrite and a 6 cell 3300 smc pack. Its litterally hammered for 2-3 seconds off throttle throw the corner then hammered again 2-3 seconds

HOLY COW BATMAN!!!

There is your problem. WAY TOO MUCH MOTOR for that small of a track. Try a 14t or even a 19t and you will probably have some better luck.

I know the motor is crazy. I built the car to spec a team car off losi web site (except the budget motor) I wanted to see what it was like to pilot a PRO 4wd. Its crazy just too hot.