Loss of engine power

Vetracr

Private
Mar 16, 2018
40
16
0
Ride
BMW Z4
I have tracked my car and use track addict to log my lap times. I have been confused by the fact that my early laps are faster than my later ones. You would expect the opposite, i.e., cold brakes and tires. I just found out the reason. BMW reduces engine power as the water and oil temperature go up. For coolant the power reduction starts at 117 degrees C water temp and stops at a 10% reduction in power at 124 degrees C. At that temperature engine will only make 90% of power. The same reduction occurs for oil temperature. Power reduction starts at 148 degrees C oil temp and reduces power until 10% reduction is reached at 157 degrees C. Every new BMW I know runs hotter oil temps than 157 degrees C when on the track. I reach 165 degrees C all the time. That means I'm only running 90% power when I'm at the track. Has anyone else discovered this problem and if so, what have you done about it?
 

doublespaces

Administrator
Oct 18, 2016
9,135
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AZ
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2009 E93 335i
Besides the obvious hardware upgrades a person could do, I'm pretty sure there is a way to adjust those tables.

Drawing blanks on who where I've read this.
 

fmorelli

Major General
Staff member
Aug 11, 2017
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Virginia
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E89 Z4 35i, F10 535d
You should consider installing an M-sport bumper. I think there is significant increase in frontal cooling area. When I get back home, I plan to do some measurements for @Asbjorn who is working on his cooling and air management. We'll make sure we post info.

Filippo
 

Vetracr

Private
Mar 16, 2018
40
16
0
Ride
BMW Z4
You should consider installing an M-sport bumper. I think there is significant increase in frontal cooling area. When I get back home, I plan to do some measurements for @Asbjorn who is working on his cooling and air management. We'll make sure we post info.

Filippo

Filippo,

I removed the Setrab oil cooler from the passenger side where the factory oil cooler is placed. I bought the biggest Mishimoto oil cooler that would fit behind the lower center grill and fit between the frame rails. I also added an oil temp gauge to the thermostat housing where the cooled oil returns to the oil filter so I have temp of oil going to bearings. I also added a water temperature gauge to the thermostat water temp input line. I'll let you know results after track event next week. Still doesn't address the computer reduction in power as a function of water and oil temp.

Larry