KF2 over heating

[Ross]

So last night my car was coming off after 5mins being warmer than normal. It has a new shell with no air holes in, so I put holes in the same place as the shell before had, I also tightened the slipper up a bit for the last round. I went out to qualifying and it cut out with around 25sec's to go.

I did my marshalling, went back to the car, the fan had been running on the speedo to make sure it cooled down whilst marshalling. I tried the car, the steering was fine but nothing from the motor, the motor was cool, I assumed the motor had gone, it did sound like it the way the car just stopped. So I went to have a chat with a few people and come back to the car, around 20-25 mins after it stopped and tried it again, it was fine , looks like it thermaled.

So I've never had an issue with any of my KF's over heating at the club until this.

So the difference on last night car to any other night was:

New shell, no holes, the holes were added.
Ball diff, I usually run a gear diff.
I had a new set of tyres on at the start of the evening, I put a new set of rears
on for the heat that it cut out on.
I've gone from a 40g under LiPo weight to a 50g but that's been on there for at least 4 meetings.

Not that it was a different set up but the gearing is 80/24.

Would the Ball diff make the set up generate more heat? That's the only big difference. It never used to get warm before this was fitted ?