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Iceman
January 13th, 2006, 21:15
In the German Car magazine "Autozeitung" is a exclusive report of a test drive with the "Audi Shooting Brake Concept".
It have a 3.2 litre VR6 with 250 hp transverse under the bonnet with a 6 speed manuel gearbox.
Nothing new here but there are a few interesting features in/on the car.
The floorplan with Aluminium Space Frame in combination with steel is the same Audi will use for the new TT.
The Shooting Brake Concept is up to the B pillar the same as the upcoming new TT.
Further features are:
40-60% power split front-rear.
Magnetic ride controle system.
Ceramic Brakes.
Touchscreen MMI monitor.
8.5x19" wheels.
245/40WR19" tyres.
RS4 style steeringwheel.
L/W/H - 4180/1840/1350mm.
0-100Km/h 6.0 Sec (car weight ± 1470 Kg)
250 Km/h limited Topspeed.

wfg, Hans.

RXBG
January 14th, 2006, 01:24
Further features are:

is this list for the new TT or the concept? is that confirmed?

Iceman
January 14th, 2006, 09:31
Originally posted by RXBG
is this list for the new TT or the concept? is that confirmed?
This list is from the Concept.
What is going to find a way in the TT is unclear at the moment.

wfg, Hans.

clam
January 14th, 2006, 11:07
40-60% power split front-rear.


Does this mean my prediction has come true?

http://www2.rs6.com/forum/showthread.php?s=&threadid=6437

That would be fantastic news. Does the magazine go into detail about it?

Iceman
January 14th, 2006, 11:35
Originally posted by clam
Does this mean my prediction has come true?
That would be fantastic news. Does the magazine go into detail about it?
That's just the problem, it don't.
It not even mention that it is a Haldex system.
But 40-60% power split sound a lot of Torsen3 to me.
The magazine say that the SBC is easely put in a controled oversteer true the corners.
Maybe Audi developed something new like a transverse torsen system.
Haldex is fitted by rear diff and Torsen by the gearbox.
Maybe Audi have put a Torsen3 between the gearbox and the Cardan shaft and drop the Haldex and install a normal diff instead.

wfg, Hans.

clam
January 14th, 2006, 12:04
A transverse Torsen is hard to do. It demands too much space. The acclaimed Evo has a transverse layout and a centre differential, but it's electronically managed (versus torque-sensing).

Another way is the one I explained in the old post. An open diff up front, and using the Haldex clutch as a slip limiter. The systems are very similar to the Evo's, b/c they both work with pressure plates. Only the location of the pressure plates would be different.

I would argue that the Haldex system with the clutch at the rear is easier to integrate and shifts weight distribution to the rear.
But the ACD system of the EVO with the clutch combined with the open diff is probably a lighter package.

Iceman
January 14th, 2006, 12:25
We have to wait and see what it will be.

wfg, Hans.

clam
January 14th, 2006, 20:55
The Shooting Brake Concept is equipped with quattro permanent four-wheel drive. A hydraulic multi-plate clutch varies the distribution of power between the front and rear wheels.

This technical solution is indeed particularly suitable for cars with the engine fitted transversely, incorporating all the well-known advantages of an Audi quattro.

Offering a permanent, situation-specific distribution of propulsive power between all four wheels, quattro drive guarantees maximum traction and, as a result, optimum acceleration at all times. At the same time there are still ample reserves for transmitting cornering forces in the interest of cornering safety and directional stability.

With the engine at the front and the four-wheel-drive multi-plate clutch at the rear, axle load distribution benefits accordingly. Indeed, this weight distribution is crucial to the excellent driving stability and good handling of the Audi Shooting Brake Concept.


This is from the press release. Doesn't help much.

Iceman
January 15th, 2006, 08:18
Originally posted by clam
This is from the press release. Doesn't help much.
I have googled a bit and fount something about the hydraulic multi-plate clutch.
Audi is using it alredy in the multitronic gearbox and in the DSG gearbox.
But the SBC is the first Audi where they use it to replace the Haldex.

Some tech explaination of multy plate clutches.
http://www.autozine.org/technical_school/traction/tech_traction_4wd_21.htm

wfg, Hans.

clam
January 15th, 2006, 13:52
So a centre differential is integrated in the DSG gearbox. And if you say it replaces haldex, then it must be a system like the Evo's ACD. In combination with AYC, this is about at good as it gets.
Have you seen the Top Gear clip where JC chases a Lamborghini in an Evo. Imagine dynamics like that in combination with Audi's chassis and engine technology. The new TT could become a very serious sportscar.

http://www.myevo.com/E7_01.htm
nice page about the Evo's ACD and AYC system

Iceman
January 15th, 2006, 14:10
Originally posted by clam
So a centre differential is integrated in the DSG gearbox. And if you say it replaces haldex.
NO, Audi uses alredy Hydraulic multy plate clutches in the DSG and Multitronic gearboxes.
The TT 3.2 Quattro have a DSG gearbox with a HMPC and a Haldex rear diff.
The HMPC is in the DSG box and the Haldex is fitted as a rear diff.
By the Shooting Brake Concept Audi use a manuel 6 speed gearbox and replace the Haldex for a Hydraulic Multi-Plate Clutch.
The HMPC can handle much more torque than a Haldex and have a 40-60% power split.

wfg, Hans.

clam
January 15th, 2006, 15:53
This is a little confusing. Haldex is a multiplate hydrolic clutch.

The whole issue with Haldex is that it isn't a differential, but a clutch (that works with hydrolic pressure plates). So it can only influence the power in one direction. If it's not engaged, then the bias is 100:0. Fully engaged will result in 50:50.
The front can send power to the rear, but the rear can't send power to the front. That means that under no circumstance can the rear have more power than the front. Because that would mean the rear has its own power source. Which is not the case.

Without a centre differential a 40:60 bias is not possible. If the Shooting Brake Concept has a 40:60 bias, then it has to have a centre differential. And if it does, then it's going to be very similar to the Evo's AWD system. The Evo also has hydrolic plates, but it doesn't use them as a clutch. It uses the plates to manipulate the differential. And in this case, a 40:60 bias is possible.

Audi could install a centre diff, and retain the Haldex system at the rear as a way to manipulate the diff. Or they could copy the Evo and integrate the hydrolic plates up front with the centre diff.

DSG or not has very little to do with it, b/c that's part of the gearbox, seperate from the AWD system. Apart from packaging issues, the type of gearbox has no influence on the workings of the AWD system.

Iceman
January 15th, 2006, 16:01
It is not quit clear to me eder how the Audi system is exactly working.

wfg, Hans.

clam
January 17th, 2006, 19:52
Whatever way it works, let's hope this is not just a typo. A centre diff is just what the docter ordered for the A-platform.