E-Brake and RS-6

[Rotary Junkie]

A parking brake typically locks one set of wheels.

Yes, the rears.

But the drivetrain cannot distribute braking force

Wrong.

so if the parking brake is locking the wheel, the transmission/drivetrain has no real say, because it's no match for the braking power.

lolwut again. If the center diff is locked then the parking brake is going to "lock" the fronts as well. Apparently you've no conception as to how any sort of AWD or 4WD system works. You know what happens when you have the rear tires completely locked and you let the clutch out in a RWD vehicle? Yeah, engine stops because the drivetrain is also locked. Same deal with AWD + locked center diff, rears are locked so drivetrain is locked so fronts are also locked.

 

[CSLACR]

Yes, the rears.



Wrong.



lolwut again. If the center diff is locked then the parking brake is going to "lock" the fronts as well. Apparently you've no conception as to how any sort of AWD or 4WD system works. You know what happens when you have the rear tires completely locked and you let the clutch out in a RWD vehicle? Yeah, engine stops because the drivetrain is also locked. Same deal with AWD + locked center diff, rears are locked so drivetrain is locked so fronts are also locked.

Ok, so the whole drivetrain will seize if the parking brake is locking a set of wheels?

Though I actually don't know how any 4wd reacts to e-brake while driving, I find it hard to believe the transmission can overpower the brakes, especially since most engines can't.

Though I should point out

But the drivetrain cannot distribute braking force

Wrong.

There's a difference between "distributing brake force" and just seizing if part of it can't rotate.
Because the drivetrain cannot distribute brake force.

If I were being picky I'd point out the FWD biased 4wd systems that only employ the rear wheels when they sense front wheel slip.

 

[Rotary Junkie]

Ok, so the whole drivetrain will seize if the parking brake is locking a set of wheels?

If the brakes are strong enough to completely stop all other forces acting upon it, yes.

Though I should point out

There's a difference between "distributing brake force" and just seizing if part of it can't rotate.

No, there isn't. At least not in this case.

Because the drivetrain cannot distribute brake force.

And why not? Explain, please, how ATVs and karts get away with one brake caliper on the rear axle then. Oh, right, that's because there's no differential to allow a speed difference between sides. Same deal here, no speed difference allowed = applying a slowing force to one "end" means applying it to the opposite end as well.

If I were being picky I'd point out the FWD biased 4wd systems that only employ the rear wheels when they sense front wheel slip.

There are also those which completely deactivate AWD if the car thinks the e-brake is engaged.


Those are also not the vehicles we're talking about here. I started off by mentioning this phenomenon happening on 50/50 torque bias vehicles (i.e locked center diff) and have since been referring to the effects of a locked center differential.

 

[CSLACR]

If the brakes are strong enough to completely stop all other forces acting upon it, yes.

Though I should point out



No, there isn't. At least not in this case.



And why not? Explain, please, how ATVs and karts get away with one brake caliper on the rear axle then. Oh, right, that's because there's no differential to allow a speed difference between sides. Same deal here, no speed difference allowed = applying a slowing force to one "end" means applying it to the opposite end as well.



There are also those which completely deactivate AWD if the car thinks the e-brake is engaged.


Those are also not the vehicles we're talking about here. I started off by mentioning this phenomenon happening on 50/50 torque bias vehicles (i.e locked center diff) and have since been referring to the effects of a locked center differential.

I fully understand what you're saying, just the difference between "applying brake force" and "drivetrain seizing" should be noted.

And in this case, if the drivetrain is seizing, all 4 tires should turn bright red, I've no idea if they are, because you haven't said, but the OP was talking about the front tires turning red.

 

[Rotary Junkie]

I fully understand what you're saying, just the difference between "applying brake force" and "drivetrain seizing" should be noted.

And why should it?

In effect there is no difference. I changed language because you did.

And in this case, if the drivetrain is seizing, all 4 tires should turn bright red, I've no idea if they are, because you haven't said, but the OP was talking about the front tires turning red.

It only "seizes" if there's enough power from the e-brake to lock all 4 tires. Otherwise all 4 will simply have braking force applied to them.

 

[Mr. CoolFiat]

And why should it?

In effect there is no difference. I changed language because you did.



It only "seizes" if there's enough power from the e-brake to lock all 4 tires. Otherwise all 4 will simply have braking force applied to them.

Very true, since the drive-train is distributing power to both axles it will just slow down them both when the parking brake is applied, not necessarily lock 'em up.

 

[CSLACR]

Yes, for some reason, until now, I wasn't able to stop thinking of starting from a stop, where the parking brake could probably hold the vehicle, but I guess in a sense it does distribute braking force, just not the sense I was thinking of.