Setting the E-brake after a track session

whiplash · 05-22-2008, 03:38 PM

OK, everybody knows you're not supposed to set the hand-brake after a track session or autocross run or even really 'spirited' driving but I've been thinking about this lately. If the 135 hand-brake is the same as the E36 M3, it doesn't clamp the pads onto the rotor, it has an actual drum brake assembly (with two brakes shoes) inside the rear rotor hat.

Does anybody know if it's the same on the 135? If so, what's the downside of setting the brake after a run? All it does is press the brake shoes against the inside of the rotor hat, nowhere near the hot rotor surface, so it shouldn't cause any warpage.

I sure as heck don't plan to test this theory and will still never set my hand-brake after a track session but the mechanical engineer in me is beginning to wonder if that concept applies to this type of hand-brake set-up?

KRZY1 · 05-22-2008, 06:40 PM

Shouldn't be that hard to see pop the wheel off pull the handle. Should be able to get a view if the pads are moving. Its a good question tho as a lot of cars have the hat/drum setup.

Mad Dragon · 05-22-2008, 07:34 PM

Every modern BMW has drum-in-disc parking brakes.

Spec Volcanic · 05-22-2008, 10:37 PM

Quote:

Originally Posted by whiplash

Does anybody know if it's the same on the 135? If so, what's the downside of setting the brake after a run? All it does is press the brake shoes against the inside of the rotor hat, nowhere near the hot rotor surface, so it shouldn't cause any warpage.

I still wouldn't set the park brake, you could warp the drum.

Doolab · 05-22-2008, 11:01 PM

Quote:

Originally Posted by Spec Volcanic

I still wouldn't set the park brake, you could warp the drum.

Yep.

Get yourself on of these, they work very well at the track and when working on the car.

alexp1_tx · 05-23-2008, 12:03 AM

Cant you just put the car in First or Revs?

Spec Volcanic · 05-23-2008, 01:07 AM

Quote:

Originally Posted by Doolab

Yep.

Get yourself on of these, they work very well at the track and when working on the car.

I use a piece of 2 X 4

Spec Volcanic · 05-23-2008, 01:09 AM

Quote:

Originally Posted by alexp1_tx

Cant you just put the car in First or Revs?

Yes and no...
no if you want to let the car run for for a couple of mins before turning it off.

alexp1_tx · 05-23-2008, 01:42 AM

Why would you let it run for a couple of min?

Spec Volcanic · 05-23-2008, 01:52 AM

To let oil and coolant circulate after a track session, to help prevent oil from cooking in the turbos, as an example

Rye · 05-23-2008, 02:27 AM

Quote:

Originally Posted by Spec Volcanic

To let oil and coolant circulate after a track session, to help prevent oil from cooking in the turbos, as an example

That's why you take a cooling lap, no? I could understand if driving local twisties, but on a track, you take a cool-down lap..or 2.

Wheel chocks work nicely also.

jeremyc74 · 05-23-2008, 08:17 AM

Quote:

Originally Posted by Spec Volcanic

To let oil and coolant circulate after a track session, to help prevent oil from cooking in the turbos, as an example

Just an FYI these cars have an after-run oil pump to prevent that.

(I'd probably still do a cool down, but I don't think cooking the oil in the turbos is going to be an issue for us.)

BMWeber · 05-23-2008, 09:34 AM

Quote:

Originally Posted by jeremyc74

Just an FYI these cars have an after-run oil pump to prevent that.

(I'd probably still do a cool down, but I don't think cooking the oil in the turbos is going to be an issue for us.)

I'm not positive but I believe it just runs the coolant not the oil after you shut the car off.

Spec Volcanic · 05-23-2008, 10:39 AM

Quote:

Originally Posted by Rye

That's why you take a cooling lap, no? I could understand if driving local twisties, but on a track, you take a cool-down lap..or 2.

Wheel chocks work nicely also.

In the time attacks I run you get one cool down lap, some cars need more.

Spec Volcanic · 05-23-2008, 10:41 AM

Quote:

Originally Posted by jeremyc74

Just an FYI these cars have an after-run oil pump to prevent that.

(I'd probably still do a cool down, but I don't think cooking the oil in the turbos is going to be an issue for us.)

just the first example I could think of

jeremyc74 · 05-23-2008, 02:31 PM

Quote:

Originally Posted by BMWeber

I'm not positive but I believe it just runs the coolant not the oil after you shut the car off.

I'm pretty sure it's the other way around, but I could be wrong. I'll have to dig into it a little.

Edit:

I dug into it and you're right. It's the coolant pump that runs afterwards for cooldown.

Here's what the N54 tech documents say about it:

After-running of electric coolant pump = improved heat dissipation from engine switch off
point. Allows protection of turbochargers by

reduced oil “coking” during heat soak.

Sorry about the thread jack!

05-22-2008, 03:38 PM	#1
whiplash Private No Class 11 Rep 203 Posts Drives: Depends on the day Join Date: Jan 2008 Location: Houston, TX iTrader: (0)	Setting the E-brake after a track session OK, everybody knows you're not supposed to set the hand-brake after a track session or autocross run or even really 'spirited' driving but I've been thinking about this lately. If the 135 hand-brake is the same as the E36 M3, it doesn't clamp the pads onto the rotor, it has an actual drum brake assembly (with two brakes shoes) inside the rear rotor hat. Does anybody know if it's the same on the 135? If so, what's the downside of setting the brake after a run? All it does is press the brake shoes against the inside of the rotor hat, nowhere near the hot rotor surface, so it shouldn't cause any warpage. I sure as heck don't plan to test this theory and will still never set my hand-brake after a track session but the mechanical engineer in me is beginning to wonder if that concept applies to this type of hand-brake set-up? __________________ They followed me home...can I keep them? Dan in Houston / CCA # 93849
	Appreciate 0 Tweet Quote

05-22-2008, 06:40 PM	#2
KRZY1 New Member 0 Rep 6 Posts Drives: Join Date: Apr 2008 iTrader: (0)	Shouldn't be that hard to see pop the wheel off pull the handle. Should be able to get a view if the pads are moving. Its a good question tho as a lot of cars have the hat/drum setup.
	Appreciate 0 Quote

05-22-2008, 07:34 PM	#3
Mad Dragon . 27 Rep 932 Posts Drives: 2010 GTI Join Date: Mar 2008 Location: MD iTrader: (0)	Every modern BMW has drum-in-disc parking brakes.
	Appreciate 0 Quote

05-23-2008, 12:03 AM	#6
alexp1_tx Private First Class 16 Rep 170 Posts Drives: Join Date: Jan 2008 iTrader: (0)	Cant you just put the car in First or Revs?
	Appreciate 0 Quote

05-23-2008, 01:42 AM	#9
alexp1_tx Private First Class 16 Rep 170 Posts Drives: Join Date: Jan 2008 iTrader: (0)	Why would you let it run for a couple of min?
	Appreciate 0 Quote

05-23-2008, 01:52 AM	#10
Spec Volcanic Private First Class 22 Rep 170 Posts Drives: 2011 BMW 1M Join Date: May 2008 Location: Calgary Alberta iTrader: (0)	To let oil and coolant circulate after a track session, to help prevent oil from cooking in the turbos, as an example
	Appreciate 0 Quote