Temperature creep under load

[S14]

So here’s an updated after installing a new valeo alternator and new original bmw waterpump, the car is running much better the amps have not gone up too much. Before the new alternator it was putting out 40amps and now around 79. I have another m3 here with 11000 miles and puts out above 100 amps.

The car now runs cooler in today’s 44c temps it was running 88c coolant temps so that’s normal
But when you go past half way mark on the blower fan it starts going up in heat back to around 96-98c coolant temps.

Any ideas guys? The only thing I haven’t changed is the ac compressor and I really don’t want to lol.

Do you have an aftermarket tune?

I was at the track a few weekends ago with this frustrating overheating problem. As I vented my problems to a BMW sepcialist shop owner who had plenty of customer cars out running that day, he said overheating S54 cars on track is common. He has seen them overheat from running lean due to old o2 sensors and old MAF sensors. I suggested my aggressive 93 octane tune might be too much for Colorado's 91 octane fuel, so I put a 1/2 tank of 100 unleaded in the car and the overheating took twice as long to develop!

His solution to overheating S54's is everything I've done (new OEM everything, CSF rad/oil cooler if the customer wants) Plus new engine input/output sensors, headers to remove the heat of the cats so close to the engine and venting the hood. Venting the hood also helps reduce front end lift.