Is the new TT getting a 40/60 split quattro drive?

[Leadfoot]

The UK car mags have all stated it, but nowhere in the latest Audi press release for the TT. Can anyone shed a little light of this.

[freerider]

IIRC, all of the cars that come/came after the RS4 will have this when equiped with Torsen.

Johan

[Leadfoot]

I might be wrong, but I didn't think that system worked with the layout of Golf platform models.

I think if I'am right that the current A3's system is similar to that of the Bugatti Veyron and it's mostly rwd with a small amount going to the front in normal driving conditions. So the same should be able to apply to the A3, S3 and the new TT.

Thought Audi UK press release talk about the use of alloy and weight balance. But doesn't talk about this which it made a big thing about with the RS4 'Driver Car' and all that, maybe this was because it's weight balance was greatly helped by this torque split.

So you would think the same should be said about the TT, but the fact that the weight balance is so much better my mean that this split is not required.

Iceman or Tailpipe, do either of you know?

[clam]

http://www.rastta.com/images/TT3.2.jpg

According to this, the TT still has the "electronically controlled multi-plate clutch", aka Haldex.

BUT, the press release says this:
----
Whereas the four-cylinder engine comes with front-wheel drive, the V6 distributes its power across both axles by way of the quattro permanent four-wheel drive system – an exclusive technology feature in the sports coupé segment.
---

Normally "permanent" means it has a centre differential. This could confirm my suspecions that I have previously discussed, that an open centre diff will be added, and the haldex clutch used as a slip limiter, and to manipulate the differential into changing the power distribution. Much like the acclaimed systems of the WRX and Evo. The way it is now the system starts out with a 100:0 distribution, and can go up to 50:50 with the Haldex clutch fully engaged. With with a centre differential it would start with 50:50, and can vary the power between 25:75 or 75:25 (circa the numbers of the WRX and Evo), giving a more practical range of distribution, and the possibility of a rear bias like the new torsen diff.

But, Haldex as it is now is performing nicely, so there's no real need for Audi to complicate matters. And if it did have a new development, they probably would've boasted about it. So I think the new TT still has the traditional Haldex system. In which case, Audi is misusing the term 'permanent four-wheel drive'.

On the other hand, the press release says it is an exclusive technology. Does that mean it's something new, or just exclusive to the segment the TT is competing in?

I wouldn't mind a 40:60 TT, but I bet against it.

[tailpipe]

Clam,

I think no one outside Audi yet knows the definitive answer to this question, but you must surely be correct.

Although much aluminium has been incorporated into the new TT chassis, it is still essentially a Golf 5 Chassis, with a transversely mounted engine, and therefore already optimised for the Haldex system. They'd be dumb not to use it. I don't think the new TT could perform as Audi wants it to without an open centre diff. The point to amke about it is that very few cars use such a comination of systems, so maybe they can describe it as an "exclusive technology". Whatever, your very well written response must surely describe the actual technical set-up they have adopted.

Given the suspension improvements over the first generation TT, I am pretty confident that this car is going to offer sensational handling. I only care about the AWD version with the V6 and DSG. While it will be interesting to compare this car to its sibling, R32 Golf, what i am interested to see is whether it can stuff the BMW Z4 coupe and Porsche Cayman. Personally, I think it will be as close as anything gets to the Cayman - but probably no cigar.

[Leadfoot]

Thanks for that, I thought "permanent" meant always on, but in German it might mean fwd in normal driving mode, who knows. I think we will have to wait until the local car mags get their hands on one and see.

Anyway in my opinion, it could drive like shit and I still would buy one. And before you say it, I am not a 'Hair Dresser', I am a 'Hair Stylist' ok.

No joking a side, I know that the R32 is a great drive machine and if the weight balance of the new TT is that much better and 200kgs lighter then it will be everything we hope it will be.

[Leadfoot]

Check this out.

http://cars.blogs.ca/2006/04/07/stunning-new-audi-tt-revealed/2/

They are saying that the new TT is rear biased AWD, it doesn't say be what percentage, but Audi have obvious informed them that this is the case.

A mechanic and a salesman in the dealer both stated this, so it must be true after all.

[syncros]

the tt has haldex.
that means technical you dont get more than 50% percent to the rear wheels.
same system as in the golf mk5, and audi a3.

[Leadfoot]

Originally posted by syncros
the tt has haldex.
that means technical you dont get more than 50% percent to the rear wheels.
same system as in the golf mk5, and audi a3.

I take it from this the maximum that the rear wheels can get is only 50% and not the 100% Audi quote in bouchers.

I hope you know more than the UK magazines because they have quoted everything from 40/60 split, 50/50split to fwd moving to awd when needed.:vhmmm:

[syncros]

well just think about how the haldex works, than you will see that it is not possible to get more than 50% to the back.

it is still a new revision of the haldex unit, faster ecu (you can get that from haldex.se for the TT1 also), easier to maintain and some other stuff like that is improved IIRC.

[Leadfoot]

Originally posted by syncros
well just think about how the haldex works, than you will see that it is not possible to get more than 50% to the back.

it is still a new revision of the haldex unit, faster ecu (you can get that from haldex.se for the TT1 also), easier to maintain and some other stuff like that is improved IIRC.

Call me thick but what is IIRC?

EVO is quoting that the new TT will have a 50/50% split and a quicker reaction to the rear wheels.

[clam]

You're thick, If I Recall Correctly. It's one of the hardest ones to figure out.

:bye2:

[Leadfoot]

Originally posted by clam
You're thick, If I Recall Correctly. It's one of the hardest ones to figure out.

:bye2:

Man, this short hand stuff that you do on mobile phones, I'll never get my head around it.

[Leadfoot]

Some have said that the new TT uses a Haldex system that is basically the same as the last TT. Now if I'am reading this right from Audi's technical spec sheet it states :idea: 'quattro permanent four wheel drive with electronically controlled multi-plate clutch, electronic differential lock EDL', if I'am not mistaking in the dictonary 'permanent' means always on. The old Haldex system in the last TT was fwd and only shifting power to the rear when the front wheels lost grip. Either Audi's not familiar with a dictonary and don't know the real meaning of 'permanent' or there is a real difference between the two systems, with the new always driving all four wheels in normal conditions.

A lot have said that the Haldex system can only put a maximum of 50% to the one axel, explain how this can be when the old system put 100% in normal drive conditions. Is the new car putting 50/50 split normally moving all of the power to where it's needed, this would give it more throttle control then the new 40/60 quattro system which can only move 25% either way.

[syncros]

haldex= electronically controlled multi-plate clutch

its permanent, already in the old tt, but you only get power to the back when you have no grip in the front.
and every haldex system can only transfer up to 50% to the _back_.

[Leadfoot]

Originally posted by syncros
haldex= electronically controlled multi-plate clutch

its permanent, already in the old tt, but you only get power to the back when you have no grip in the front.
and every haldex system can only transfer up to 50% to the _back_.

syncros,

I have not doubt you are more clued up than I'am, but can you explain why my TT 225 would oversteer more often than my current S4 when one can onlt sent a maximum of 50% to the rear and the other 75%? By the way I'am talking about wet driving.

[syncros]

suspension setup, whatever. my stock ttqc with sline suspension handled quite safe and understeered in most situation.
now with my pss9 coilovers it drives stable and neutral up to a point where the rear breks away :D

[Leadfoot]

I see in World Car Fans the full spec of the quattro system is explained.
The Audi TT with the four-cylinder TFSI is fundamentally a front-wheel-drive model, whereas the V6 features permanent four-wheel drive. Its quattro drive system, developed specially for transverse-mounted engines, operates with an electronically controlled and hydraulically actuated multi-plate clutch. In order to improve the distribution of axle loads, the clutch is positioned to the rear of the TT, at the end of the propshaft in front of the rear axle differential.

The package of plates, which runs in an oilbath, can be compressed under a controlled pressure potentially as high as 100 bar – the greater the pressure, the higher the drive torque that the clutch can transmit to the rear axle.

The structure, comprising a separate oil supply and two axial-piston pumps, permits a pressure buildup with lightning speed. In normal driving conditions, the clutch directs 85 percent of the torque to the front wheels, but in extreme circumstances it is able to transmit as much as 100 percent of the forces continuously to one of the two axles.

Compared with the unit in the predecessor model, the service intervals for the quattro drive have been doubled to 60,000 kilometres. The mechanical construction and the precision of the control function have likewise been further enhanced, and the mapped characteristics given sporty settings. The clutch's control unit evaluates a large variety of data, including wheel and engine speed, road speed and engine torque. It also identifies the driving situation and the driver's intentions, and takes them into account in its control strategy.

This adaptive distribution of torque enables the quattro drive system to achieve particularly high traction and outstanding acceleration. It also provides ample reserves for the transmission of cornering forces – assuring TT drivers optimum safety and lots of driving fun whatever the conditions. The competitors in this segment have no comparable solutions to offer.

So, not 40/60 split but 85/15 in normal motorway driving and upto 100% to which ever axle needs it. I like the fact that it upto 60,000 Km on services for system. And the system now shifts the power more quickly, looks like it's going to be a great driver's car.

[minimad]

Originally posted by syncros
haldex= electronically controlled multi-plate clutch

its permanent, already in the old tt, but you only get power to the back when you have no grip in the front.
and every haldex system can only transfer up to 50% to the _back_.

how this thing works? can they transfer more than 50 to the rear?

http://www.hpamotorsports.com/product_drivetrain_haldex.htm

[syncros]

it is mechanically impossible to transfer more than 50% power to the back with a haldex!

[Leadfoot]

Originally posted by syncros
it is mechanically impossible to transfer more than 50% power to the back with a haldex!

syncros,

Someone better inform Audi, could that not what they say in their info for the TT.

I don't doubt that you know a lot more about this system than me, but after owning an old TT quattro and what it would do ,put full steering lock on, dump the clutch and throw the tail like a rwd car, does not sound like a car that at best can only put 50% of it's power to the rear wheels.

I have tried this with my S4 which is proper Quattro and it can't do it. Explain this to me, because if you are right the S4 should be able to do it and the TT shouldn't. And by the way I'm not talking about a wet surface.

[Leadfoot]

This arguement keeps coming up that Haldrex can only transmit 50% of it's power to the rear wheels.

This is the latest details of the S3. With the section on quattro system.

In common with all other S models, the new S3 has four driven wheels – an advantage that its direct competitors cannot match. The nerve-centre of the quattro drive technology that was developed specifically for transverse engines is an electronically controlled, hydraulically actuated multi-plate clutch: this is where the engine's power joins forces with the transmission's intelligence.

This clutch is located at the end of the propshaft, in front of the rear axle differential – the installed position at the rear improves the axle load distribution. A package of plates running in an oil bath within the clutch housing can be pressed together by controlled hydraulic power. The higher the pressure becomes, the more drive torque is diverted continuously to the rear axle.

The hydraulic multi-plate clutch: a pressing matter

The design, with a separate oil supply and two axial piston pumps for a rapid pressure buildup, permits lightning-fast reactions when the driving conditions change – the clutch's control unit constantly analyses the situation on the basis of a wide range of data.

Depending on the degree of slip between the front and rear axles, an oil pressure that squeezes together the package of plates builds up. At its extreme, as much as 100 percent of the drive torque is diverted to just one set of wheels. The superimposed electronics are able to regulate the oil pressure and therefore the torque distribution as dictated by the situation.

This equips the Audi S3 with maximum traction and slip-free acceleration from the moment it starts to move. It also provides ample reserves for the transmission of cornering forces – S3 drivers consequently know they will benefit from optimum safety and lots of driving fun whatever the conditions. From the clutch to the wheel bearings, the drivetrain has been reinforced in every critical area, thus enabling it to transmit the engine's high propulsive power with confident ease.

Now I don't understand it all, but I do get the part '100 percent can be diverted to either axle.'