BMW's fancy DPC Diff.. usable in motorsport?

[Zico]

How much of an advantage would this type of diff be on the track.. it sounds great, all the advantages of maximum mechanical grip and power vectoring albiet with an aprox 25lb weight penalty.

"Dynamic Performance Control switches power between the left and right rear wheels to stabilise the vehicle within milliseconds and help increase traction and lateral acceleration. Handling is lighter and more precise during normal as well as difficult driving conditions.How Dynamic Performance Control works can best be described in canoeing terms: if you want to turn right when canoeing in the main current, you can brake using the paddle on the right side of the canoe. This is how most common electronic stability programs work. Alternatively, you could use the paddle powerfully on the left side of the canoe in order to have more control in progressing forwards and turning right. This is the principle behind Dynamic Performance Control.It links the standard rear differential with a mechanical planetary gear set and an electronically controlled multi-plate clutch for each rear wheel. Its mechatronical system combines informatics, electronics and mechanics to process complex data such as the yaw rate, wheel speeds, steering angle and engine torque so that it can react immediately: when required, the system ensures that drive power distribution to the rear wheels can be freely varied and increased on either side as needed. The power distribution can also be displayed on the onboard computer.Dynamic Performance Control increases directional stability when accelerating out of bends and provides the driver with extra support when dealing with difficult driving conditions. Before under- or oversteer can take place, lateral guided force is used to keep the vehicle on track. Precise steering significantly increases driving comfort and safety.Dynamic Performance Control is also effective when the vehicle is coasting - when the driver removes their foot from the accelerator - or when they have pressed the clutch pedal. If the rear wheels are on different types of surfaces, Dynamic Performance Control improves traction by supplying more drive power to the wheel with more grip. A wheel torque difference of up to 1,800 Nm can be actively created between the left and right rear wheels. This increases driving stability and allows for much faster acceleration.As a logical progression to the xDrive all-wheel drive system, Dynamic Performance Control can be matched to all drive concepts and engines. Whereas xDrive variably controls the power distribution between the front and rear axles, Dynamic Performance Control intelligently distributes power between the two rear wheels. This results in precise handling whatever the driving conditions."



What would its practicality be in the real world?.... should we expect to see it in future M cars?... and what other diffs similar to this have been used succesfully in motorsport?

http://www.truveo.com/BMW-Dynamic-Pe.../id/3906521958

[AU N EGL]

Originally Posted by Zico

How much of an advantage would this type of diff be on the track.. it sounds great, all the advantages of maximum mechanical grip and power vectoring albiet with an aprox 25lb weight penalty.

snip

What would its practicality be in the real world?.... should we expect to see it in future M cars?... and what other diffs similar to this have been used succesfully in motorsport?

http://www.truveo.com/BMW-Dynamic-Pe.../id/3906521958

Big fancy term of Active handling and traction control

Yes it has a huge advantage in racing to help prevent slipage on high speed corners.

and why F1 just banned AH and traction control with other sports series to follow if they haven't.

AH and TC are for ppl who IMO, do not know how to drive properly and must relay on mechanical and computer aids.

[Zico]

Originally Posted by AU N EGL

Big fancy term of Active handling and traction control

Yes it has a huge advantage in racing to help prevent slipage on high speed corners.

and why F1 just banned AH and traction control with other sports series to follow if they haven't.

AH and TC are for ppl who IMO, do not know how to drive properly and must relay on mechanical and computer aids.

Yep, Ive never heard of an active diff being called Active handling as you put it, I guess its an american term, but your correct, its basically just an electrically controlled active diff marketed as though its something new.

Thanks..

[Rubinho]

Originally Posted by AU N EGL

AH and TC are for ppl who IMO, do not know how to drive properly and must relay on mechanical and computer aids.

Very naive. The driver is another component of a race car and just as you seek to use engineering solutions to optimise the mechanical parts of the car you must find gains from the "fleshy" bit too. Would you shun tuning suspension and geometric setup as it makes the car handle thus easier to drive?

[R59]

Rubinho, there are two schools of thought here.

There's the engineer who feels that we should make use of every last bit of technology to make the car as fast and as efficient as possible. Some of that technology takes away a little of the "seat of the pants" ability of the driver, placing it in the hands of an MCU somewhere on the car.

There's the driver who feels that cars should be simple - straightforward to set up, responsive to chassis tuning, but in the pure sense, as fast as the nut behind the wheel who "feels" the car.

Don't get me wrong, I think these gizmo's are wonderful, but I'm of the opinion similar to AU N EGL, where we should all run basic diff's - be they stock, spools (locked), mechanical torque biasing, viscous, or old fashioned plate, and our gearboxes should have H-pattern gear shifts, with a pedal on the left called "Clutch", and so forth. Whether that's in a saloon, sportscar, or single seater, it puts much more emphasis on the skill & capability of the driver.

I will admit to have gone faster in things with "bells and whistles", but I've had much much more fun in things that are "agricultural" to say the least.

[R59]

eeeeek! Duplicate posting! Damn you computer!

[diabloA1]

In motorsport. The objective would be crystal clear. Whatever brings down lap times. If we find ourselves in the scenario where the car does 'all the driving' so be it! Provided it gives lower lap times.

In real world application I think it's not so easy. It boils down to what the the manufacturer think the driver (customer) would like. Some drivers like to take corners sideways because it's more fun eventhough its actually slower

[AU N EGL]

Originally Posted by Rubinho

Very naive. The driver is another component of a race car and just as you seek to use engineering solutions to optimise the mechanical parts of the car you must find gains from the "fleshy" bit too. Would you shun tuning suspension and geometric setup as it makes the car handle thus easier to drive?

naive? no not at all.

Race Series rules say if one of these fancy diffs or AH/TC can be used or not. If tech rules do not allow it, then you cant use it.

I spend a large amount of time on supension set ups for each race and each different track. Keeping a log book for each track.

I drive, race and teach 'seat of the pants" race driving. If you cant FEEL what is going on, what are you going to do when it is broken? Fix it? not when you have 10 min to grid, or your a club / semi pro racer and it is only you and one other guy.

[AU N EGL]

the other aspect about all the computer gizmos, is when, and they will, break. Down time, repair time and repair costs hurt teams and club drivers.

Nieve is thinking a race car can go a whole seasion without maintaince.


and R59, going "agricultural" is a learning expericnce in itself.