Went to race with "hobby race event", where they race with regular Rotax Max and DD2 versions of racing karts.
Event was with 15 laps (thats 5 laps to many for my reqular driving) but I tried it anyway.
First race everything was cold enough so at the end of the race everything was in ok temperatures.
I had on some old rear tires and sadly they did not gave me enough grip in the corners
As I drove out to the grass, then motor got time to cool down a little bit, but at the end was over 100C.
And here is also video for race 1 https://youtu.be/_OjEdIBejoE
I knew that I can not parcipate in every race (they had 5 races and with 50 to 60 minutes apart) so I was aiming first and third and fifth.
But as I recharged my battery and changing rear tires to also used but in my opinion better tires the battery did not want to cool down at all.
And as I finished first race with 38 to 45 degrees battery temps, I started my second race with 33 to 41 degrees temps. So my bottleneck is indeed battery and not motor.
It seems that one of the temp sensors is not touching cell interconnect but the plexi glass behing it.
For the next event I was thinking to bring along cooling case with ice in it (the one thats ment to be to cool beers) and then I unmount battery and stick it into that case for charging. This should bring enviroment around battery to 0 degrees and its then 22 degrees lower that it was in the air that day
And i only drove 10 laps out of 15 in this race, because I saw that my motor temp was almoust 110C and I was tired also, so no point to brake the motor.
You can see also from the lap times that 6 laps I could do it and then my arms started to hurt and I lost 1s with a lap
And video for race 3 https://youtu.be/fD9kfT3C6oQ
As battery temps rised over 50 degrees and I knew that they will not come down with 2 hours that I had between next race I did not raced thir fifth race.
A123 20Ah pouches are working good up to 55 degrees and I know that already over 50 in my temp measurement they do not perform very well anymore.
Both times I have restricted the controller for 60% of maximum torque and motor RPM were limited to 5000, because over that I'm not gaining anything in the track.