After seeing the 3.2 A3 at the auto show, I was wondering have I missed something about benefits of Quattro. Ok sure I understand the benefits of better handling and stability, but is it really beneficial.

It’s now made the A3 1495kg, that's heavy for a hatch. If you look at the suspension setup of the car it still sits so high still and does not have a good centre of gravity. I test drove the 1.9TDi, despite the improved independent suspension links the handling still isn't the greatest. Now add Quattro. Do you really think handling is going to improve? My feeling is you will reach the handling limits of the vehicle before Quattro becomes beneficial. Take a corner fast you'll probably have 3 tires in contact with the ground, haldex will shift the power to the rear where traction is needed, but you only have 1 tire in contact with the road ? So now what is the point of it on a vehicle like this.

I understand the benefits of Quattro on the S cars where suspension is setup to benefit from Quattro, and you can feel the difference.

I don't know for how long I've ben saying that 4WD improves traction, not necessarily handling.

Handling involves traction & lots of other components like:

- Grip (4WD doesn't give more grip, grip is related to tyres & tyre width)
- centre of gravity
- weight
- weight distribution
- polar moment on inertia
- ride height
- suspension stiffness
etc

Hanlding has more to do with suspension than drivetrain layout. And on most tracks you won't be spinning your wheels on the xit to every corner (unless you have 1000NM) so quattro won't even help with traction. Around Kyalami, for instance, an M3 doesn't reach 2nd gear at any point (OK you can go to 2nd in 2 spots but you don't have to if you carry enough speed in). Now, I can't spin the wheels in 2nd gear so 3rd gear will have no traction problems anywhere on the track.

I agree with I8 - the handling of a A3 with or without quattro has to be the same assuming the same suspension setup. Quattro on its own would change the weight distribution to more weight at the back, but that is not significant.

Quattro does not add anything to the handling of a car at the limit as quattro only has an impact when you are on the throttle. If you are able to apply throttle when you are at the handling limit, you are not at the limit!

Quattro's advantage is that it allows you to accelerate earlier and harder than with 2wd as you are spreading the traction over 4 wheels rather than 2 (and with quattro distributing power where needed). This becomes even more important in slippery conditions. For this advantage you give away some drive train losses and extra weight. Personally I would find it difficult to ever buy a car without awd as for me the traction advantage outweighs the disadvantages.

I8 I agree with you that Quattro improves traction, but disagree with you at it does not improve handling.
If the suspenion and other factors are setup specifically for Quattro it will improve handling. It should be correcting factors like oversteer and understeer according to the conditions, bu applying power distribution to the correct wheel. But like I said above I don't think it will work when suspension limits are reached before Quattro can be utilised.

My point exactly; car companies are giving us these porky cars and proclaiming them to be 'performance vehicles'...

It has got to stop some time, and I hope that with Audi 'quitting the power race' they will pay attention to making lightweight cars.

The criticism against Haldex is valid as well (you know how I feel about that!), rather get a system which is geared to getting you through corners quicker in ALL situations than creating a reactive system which is only a preventative measure in case traction is lost.

Gandalf is right. The advantage is traction & getting on the throttle earlier. The disadvantage is more weight, worse weight distribution (compared to RWD), & more drivetrain loss. So having got onto the throttle a fraction earlier 50m down the next straight the extra weight & drivetrain loss means a similarly powered 2WD car will already have overtaken you & by then end of the straight pulled a lead on you.

So, if the track has lots of hairpins & tight bends the 2WD car might not make up the time it loses on traction. But on a track with long straights or high speed bends the 2WD car will be king. Case in point M3 vs S4 around Kyalami. The BMW advanced driving instructors are doing 2:06's 3-up & the Audi Academy instructors are doing 2:12's. But then again, Kyalami doesn't have any tight bends where 4WD can make up time. Might be closer at a track like Zwartkops.

Kevin, think about it for minute. ALl cars understeer on the limit. You can't get on the throttle too early or the understeer will be worse. Now a car understeers when the front tyres run out of grip & start to slide. So, the limit for a cars handling is how much G's the front tyres can handle. It doesn't matter how much the rears can handle as the front will always give way 1st, by design.

So for cornering grip, it doesn't matter that the power is distributed amongst 4 wheels. Once the front starts sliding you've reached the limit. So some may say that seeing as a RWD car sends no power to the front, the front tyres have more grip available for cornering. Which is why normally RWD understeer less than 4WD.

Ok I understand the dynamics of the Quattro system, but my point is why are they putting Quattro on the A3 3.2 when they should have rather spent their time improving the suspension first. Why add all that weight when it has no benefit on a car like the A3 3.2 because the setup is incorrect.

I know everyone is speaking above of a Quattro system on a car that has a lower centre of gravity as setup correctly, and I agree totally about majority of the above comments , but on the A3 ?

I recently have had another reminder as to the consequences of poor weight distribution and **** front traction going around Zwartkops on Saturday. Cant comment on other quattros around a track as I have never taken any others, but as for my urS6, I was horribly dissapointed with the understeer I experienced. Although I attribute the severity as opposed to my previous occasions on a track to the fact that I've got bad tyres on front, I think the biggest issues is the weight distribution and the "nose heaviness" of my quattro.

AWD had no benefit around the corners when on the limit, where you are not accelerating or braking. All available traction is concentrated on the cornering forces, and the weight of the nose justs pushes you off the line.

As Gandalf mentions, braking hard first to reduce your entry speed and then accelerate through the corner helps, but then what I8 says comes into play. Acceleration and cornering forces on the tyre at the same time again induce understeer, but I found to a lesser extent that coming hot into the corner as power gets distributed to the rear.

Ultimately, the poor weight distribution of my quattro is what frustrates me the most around a track. My longitudinally mounted engine sits literally in front of the strut brace between the shock mountings, whereas a BMs motor sits at least in between the two front wheels if not even further back with the strut brace running over the top engine

Hi,

Jeesh! I don't know too much about all the technicalities you guys are talking about, but the mere fact that quattro was banned from certain races as being "an unfair advantage" tells me it's not all that bad...

Also look at the earlier rally days - who had the upper hand? quattro?

Perhaps pushing/pulling forces also come into play?

FWD = pulling the car through a corner
RWD = pushing the car through a corner
AWD = both, so power to the wheels are more evenly distributed to go faster?

I agree the A3 3.2 is a bit high (perhaps top-heavy) to make the quattro work at it's optimum.

Alex

Alex, banning awd from certain racing classes is a very different issue. If the cars in the class have a minimum weight limit, a 2wd and awd car are both going to weigh the same (it is quite easy to put a race car on a diet). The only difference then is the power loss due to quattro vs the additional traction. Also, over a full race, you use up your tyres and the quattro advantage becomes even larger. Then if it rains there is no competition!

What we are talking about here is the exact same car with and without quattro. The quattro car will be heavier and have less power at the wheels as negatives whereas the positive is that it has more traction. Given that the suspensions are the same, both cars would handle equally as well (not true the heavier car would handle less well). Handling is about suspension setup and quattro is about traction. I would still always choose the awd car!

Grant, I am sure we can do lots to improve the handling of your car as I said in my email.

There is a guy I have found on the Original S Car Audiworld forum that manufactures stiffer anti role bars. This is probably the best route to go.

Looks like the Happersized 26mm is about your only option. The advantage is that it is adjustable, which is very handy in setting the car up. I am worried that if you go from 17mm (stock) to 26mm it might be a bit too stiff - according to Whiteline it will be 447% stiffer! The Whiteline rear ARB made my S2 only 157% stiffer (it is adjustable so I can still go to 216%). You might have to get a stiffer Front ARB to balance things out.

See http://www.whiteline.com.au/docs/bulletins/010barup.pdf

Even just stiffening up the rear of the S2 by 157% got the car to oversteer

Because oversteer is fun!

Apparently the Golf R32 roll bar is a good route to go (with an S3), it stiffens things up nicely and allows you to tighten the line rather nicely. The only problem with mods like these is that they are probably more trial and error than anything else...

Take away the understeer and enjoy your AWD? I guess that's what it all comes down to.

Get some spacers on the S3 as well. That decreases the understeer too.

Jason, H&R makes a matched set of ARBs for the S3 (25mm front and 21mm rear). Eibach also makes a set of ARBs.

Yup, seen those, heard some reports about the Neuspeed ones as well. Gandalf, have you replaced the ARBs on your car?

I'm not too interested in sorting out the situation with (fairly) costly mods if I'm going to be selling anytime soon, that's why I don't moan about it any more.

On the S2 I replaced the Rear ARB with a Whitespeed adjustable and the S2 Front ARB with a RS2 FARB. The car is currently getting a racing H&R and Bilstein suspension and I'll report back how well that works. The ARB's made a huge difference with the stock suspension - much less body roll and much more stable on uneven roads.