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      07-26-2011, 11:58 AM   #599

Drives: 335I
Join Date: Jun 2009
Location: Illinois

iTrader: (2)

Originally Posted by vasillalov View Post
There is no need to educate me how the heater core works.
No problem, as long as you get my point, which is that its the Heating core that's causing the coolant temp drop, not any other AC component. Which is why most of us run the heater on full blast at the track. I usually turn on the air, then press the * button to make sure the compressor is off, then crank the heater up to 84 degrees, and turn the fan on to the highest setting. It isn't uncomfortable at all, as you run at the track with both windows down, so you can give hand signals. Leaving the compressor on, and turning the temp dial down to 60 something degrees, and winding up the windows, won't yield half as much coolant temp decreases as running the heater the way i described earlier. Also note that the temp drop achieved with the heater on, full blast, is only temporary. It helps, but not as much as you think. At the track, the car is constantly adding an A$$ load of heat into the system, so your running against the inevitable. Usually with the heater on, you'll drop from 98C coolant temps to 93C instantly, but however, it will creep back up after about 2 laps.

The biggest factor at the track is ambient temps. Anything over 75 degrees with our car, is very difficult. at 50 degrees, you might not even need an oil cooler!

Originally Posted by vasillalov View Post
Finally, while I don't have much track experience just yet, I am trying to get as much seat time as possible. At the moment, the car that I have is too much of a car for my skills as a driver, so I am currently not able to push it to the limit.
Come on down to the track anyways! as a novice, you can just get driven in your car, by an instructor. It will really be a great experience for you, and you will get to see how awesome the E90's are! Nothing like the way the G forces hit you in a turn, when a pro is driving your car!

Originally Posted by vasillalov View Post
But when that happens, I will be most definitely concentrating on proper radiator cooling as I do believe that coolant temperatures govern the oil temperatures. Why else do you think the PPK has an extra radiator?
Take care and good luck on the track.
You already use an extra radiator when you turn on your heater. Complete with a fan blowing on it. That tiny 0.5Liter radiator in the PPK isn't doing as much as you think. Remember, its not the radiator capacity, its the percentage of coolant (relative to water) in it that matters. With stock 50/50 coolant/water mixture, even the 1M oil temps have been going over well over 270 degrees at the track (At 270F, our cars loose power) when ambient temps are over 75F. A car with just a 2Liter radiator but distilled water (or <30% coolant) + water wetter will be 3X cooler at the track than a car with a 3Liter radiator and 50/50 coolant/water mix.

Also remember that the PPK has a larger fan + air scoops for both the oil and coolant coolers, and a reprogrammed computer which runs the water pump and fan much longer and harder than stock. To handle this additional electrical power demand, it has a larger, or additional battery. So don't expect the same results with just the additional radiator.

Last edited by Turkeybaster115; 07-26-2011 at 12:13 PM.