Overheating during track sessions

[Asbradley21]

So I've begun to more actively do HPDE's in my m42. During each 20 minute session after a few laps the temp needle will hit the 3/4 mark and stay there. I already use the lower temp thermostat. The car does not overheat in normal use, just on the track when it gets pushed hard continuously.  What do I do? Do I need a new radiator? Should I convert to an e-fan? Do I need a mishimoto radiator? If so, which?

Thanks in advance
-Austin

[DesktopDave]

I'd suspect the pump if all else is OK.

[76m2002]

I just tracked our m42, and it never got hot on the track.  I would suspect the radiator.  When you are on track at speed, the engine makes a lot of heat.  Normally, there is enough airflow in the radiator to cool the engine.  For example, in my M2 the electric fan never kicks on when on track, since there is so much airflow.  
Ian

[Asbradley21]

I think my current plan is going to be to replace the radiator with a mishimoto aluminum and replace the waterpump while I've got it out. What electric fan set up are you running?

[76m2002]

I have a home-brewed setup.  You can get a fan relay, and connect power to the relay, then to the fan.  You can mount the sensor in the radiator, or in an adapter that splices into the line out of the radiator.

[76m2002]

Looks like Ireland Engineering sells a nice kit with everything you need:
http://www.iemotorsport.com/bmw/2002-cooling/fan12kit.html

[Asbradley21]

Thanks. I'm going to go with a spal 16in fan for some more airflow and then going to get the zionsville shroud and expansion tank. Should do for some good cooling.

like this.


I would really like that sensor and wiring/relay kit though... Just don't need the fan.