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      05-06-2019, 04:47 PM   #45
reyoasian
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Any way to code off rear-braking on xDrive?
Don't want to cook my brakes.
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      05-08-2019, 07:43 AM   #46
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Quote:
Originally Posted by reyoasian View Post
Any way to code off rear-braking on xDrive?
Don't want to cook my brakes.
You're asking for trouble. Rear braking stabilizes the car.
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      05-08-2019, 09:28 AM   #47
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Originally Posted by kern417 View Post
You're asking for trouble. Rear braking stabilizes the car.
I haven't tried disabling the eLSD via coding yet. If you have a mechanical LSD, it might be fine.

As for brake ducts, I know that the M Sport package has air ducts for the front brakes so I view aftermarket ducts as unnecessary.

Better pads like Pagids for the M Sport/M Performance Brakes and fresh brake fluid (even OEM BMW DOT4 brake fluid) is plenty for HPDEs.

I've consistently ran F80/82 M3/M4 brake pads in my M Sport Brakes when the car is shared between my girlfriend and myself at HPDEs. Of course, my powertrain is largely stock. so I wouldn't be going nearly as fast as M3/M4s down the straights to completely overwhelm their brake pads.
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      05-08-2019, 11:04 AM   #48
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Quote:
Originally Posted by Polo08816 View Post
I haven't tried disabling the eLSD via coding yet. If you have a mechanical LSD, it might be fine.

As for brake ducts, I know that the M Sport package has air ducts for the front brakes so I view aftermarket ducts as unnecessary.

Better pads like Pagids for the M Sport/M Performance Brakes and fresh brake fluid (even OEM BMW DOT4 brake fluid) is plenty for HPDEs.

I've consistently ran F80/82 M3/M4 brake pads in my M Sport Brakes when the car is shared between my girlfriend and myself at HPDEs. Of course, my powertrain is largely stock. so I wouldn't be going nearly as fast as M3/M4s down the straights to completely overwhelm their brake pads.
Idk if you meant to respond to me, but I'm not arguing any of your points. All I'm saying is if you disable rear braking, you risk the rear end coming around on your during hard braking. You need some bias to the rear to keep the car stable.
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      05-09-2019, 10:58 AM   #49
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Quote:
Originally Posted by kern417 View Post
Idk if you meant to respond to me, but I'm not arguing any of your points. All I'm saying is if you disable rear braking, you risk the rear end coming around on your during hard braking. You need some bias to the rear to keep the car stable.
I think only the first part was in response to you but the rest was directed to the OP.

So I believe the M Performance LSD does have some lock during deceleration which tends to straighten out the rear of the car. If you have an open diff, I would completely agree with you. Disabling eLSD on an open diff car is asking for issues in inclement weather - snow.
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      05-09-2019, 11:57 AM   #50
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Ah gotcha.
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As long as 3-pedals are an option, I will exercise my right to suffer the handicap and indignity of slower shifts and reaction times.
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      05-16-2019, 12:23 AM   #51
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Originally Posted by Polo08816 View Post
Quote:
Originally Posted by kern417 View Post
Idk if you meant to respond to me, but I'm not arguing any of your points. All I'm saying is if you disable rear braking, you risk the rear end coming around on your during hard braking. You need some bias to the rear to keep the car stable.
I think only the first part was in response to you but the rest was directed to the OP.

So I believe the M Performance LSD does have some lock during deceleration which tends to straighten out the rear of the car. If you have an open diff, I would completely agree with you. Disabling eLSD on an open diff car is asking for issues in inclement weather - snow.
The eLSD only comes on in DSC OFF, and it uses the rear brakes to mimic an lsd. DSC doesn't work that way as it manages power sent to the spinning wheel(s). An open diff with eLSD off would be fine in inclement weather.
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      05-16-2019, 04:23 PM   #52
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Originally Posted by kern417 View Post
You're asking for trouble. Rear braking stabilizes the car.
I mean during turns, the inside-braking (fake LSD)
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      05-17-2019, 07:08 AM   #53
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Quote:
Originally Posted by Logicoeur View Post
The eLSD only comes on in DSC OFF, and it uses the rear brakes to mimic an lsd. DSC doesn't work that way as it manages power sent to the spinning wheel(s). An open diff with eLSD off would be fine in inclement weather.
DSC and eLSD are pretty much the same things. You can't send more power to one wheel or the other without an actual LSD. All our cars do is manage the brake bias when accelerating, turning, etc. It's all ABS programming.

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Originally Posted by reyoasian View Post
I mean during turns, the inside-braking (fake LSD)
You want that. If it's cooking your brakes then turning it off just means you'll lose the rear end. Our traction control isn't that invasive that it slows you down when driving at the limit. Just prevents you from going past it.
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As long as 3-pedals are an option, I will exercise my right to suffer the handicap and indignity of slower shifts and reaction times.
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      05-17-2019, 08:48 AM   #54
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Quote:
Originally Posted by kern417 View Post
Quote:
Originally Posted by Logicoeur View Post
The eLSD only comes on in DSC OFF, and it uses the rear brakes to mimic an lsd. DSC doesn't work that way as it manages power sent to the spinning wheel(s). An open diff with eLSD off would be fine in inclement weather.
DSC and eLSD are pretty much the same things. You can't send more power to one wheel or the other without an actual LSD. All our cars do is manage the brake bias when accelerating, turning, etc. It's all ABS programming.

Quote:
Originally Posted by reyoasian View Post
I mean during turns, the inside-braking (fake LSD)
You want that. If it's cooking your brakes then turning it off just means you'll lose the rear end. Our traction control isn't that invasive that it slows you down when driving at the limit. Just prevents you from going past it.
If it was the same then we'd cook the brakes all the time. Cutting the power to a wheel isn't the same as applying the brakes to said wheel. ELSD prob does both in tandem, but dsc definitely can't be applying brakes all the time. Since it's an open diff though you could be right. BMW does really weird things compared to everyone else it seems.
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      05-17-2019, 10:48 AM   #55
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Quote:
Originally Posted by Logicoeur View Post
If it was the same then we'd cook the brakes all the time. Cutting the power to a wheel isn't the same as applying the brakes to said wheel. ELSD prob does both in tandem, but dsc definitely can't be applying brakes all the time. Since it's an open diff though you could be right. BMW does really weird things compared to everyone else it seems.
eLSD is a crappy term. It's just a form of traction control. If one wheel loses traction, it brakes the wheel with traction so that there is a load on the diff and the other wheel can continue putting down power. It's less power than an actual LSD would put down, but more power than just the Open diff. Without the eLSD controlling the brakes, no more power is being put down and you're just spinning the inside wheel. You're faster with the eLSD on. That's also why we can do a burnout and lay down two tire patches with an open diff. It's modulating the brakes so both wheels keep spinning. Without it, only one wheel would spin.

DSC controls the response time when the car begins to lose traction. So it lets you get a little sideways and put more control on the driver. But again, sliding isn't fast on tarmac so you really want to keep it on.

Both are only used when you're losing traction. When traction is good, even at the limit, no extra braking is being applied. But an open diff cannot physically in any way send more power to one tire or the other. An actual eLSD like what's in the F8x cars, where electronic actuators shift clutch plates in the diff, is what we really want to push power to the wheel with traction rather than compensating for the wheel that doesn't have traction. But it's cheaper and more economical for BMW to do it this way with controlling it using the ABS module.
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