I'm still in the early stages of the buying cycle and am focusing on a 97-98 C2, C2S, C4 or C4S. I've been speaking to as many people as possible and heard interesting and conflicting information about the function and effectiveness of quattro vs. psm vs. 993 awd.

By way of background, I currently own a TTQR, so that's my baseline for comparison of performance awd systems.

While testdriving a 99 C4, I asked the dealer about similarities/differences in the function and performance of quattro vs PSM. His answer was that quattro is an "inclement weather" system, while PSM is "performance-oriented" and "better." Obviously, he is slanted in his viewpoint and wants to make a sale.

I then went to a local Audi/Porsche specialist race & repair shop and asked the same question. The lead mechanic thought that quattro was a much more advanced system, both on and off the track. He said that while the C4 awd setup and PSM are very effective and good enough for most people, that "Porsche only made the system 'good enough,' while Audi took the concept as far as possible." He was speaking specifically about quattro vs. 97-98 C4 awd and not of late-model brake-integrated PSM.

So, any other thoughts?

 

John,

Check out this thread on the 996 board. I think it will answer many of your questions.

THREAD LINK

I think from reading your question you understand the difference but for anyone not familiar with PSM it is NOT an all wheel drive system it is an electronic drivers aid (PSM = Porsche Stability Managment), basically an advanced traction control system. PSM comes standard with the 996 C4 but is also available on rear wheel drive 996s.

 

Brian,
Thanks for the link. I hadn't searched in the 996 forum since I'm pretty focused on the 993.

Any other 993-specific comparisons or comments I missed?

Thanks all,
John

 

A friend of mine put it this way:
"Quattro is an enabling device. Traction control is a disabling device."

With Quattro or any other AWD system, power is simply re-routed to the corner(s) that have the most traction. There are variances in the many systems out there, with varying levels of biases. The Golf R32 is FWD until slippage occurs. The new Infinity G35 is RWD until slippage occurs. I think Lamborghini's is something like 15/85 F/R under normal conditions.

With traction control, power is actually *cut* until traction has been regained. Some systems are more aggressive than others.

I know someone who tried to climb a hill in a car with traction control and was getting frustrated as the engine kept on cutting out on him. He argued that this was less of a problem with his FWD car without any traction control.

PSM is a variant of traction control. Introduced with the 2000 996 models, it factors in more variables, allowing some slippage, vs. the standard TCS which was an option with the 1999 996. The C5 Corvette has a multiple mode TCS as well. As with PSM, the track mode actually allows some loss of traction before reeling the car in.

Arguably, the quattro has had a long history of success both in passenger cars and in rally conditions. It is extremely robust and virtually bullet proof. I don't know enough of the Porsche AWD system to make the same comment but if logic stands, the longer you develop something and the more units you make of it, the better you'll get at producing it.

As to the performance angle, AWD will beat 2WD in rainy conditions, hands down. In the dry, AWD offers better pull out of the turns and on start but may be offset by the additional weight in handling. In the case of the Subaru WRX I drove, if you drive it like a normal RWD car, you will get some understeer in the turns. To drive it more efficiently, you will lift slightly as you enter the turn, and nail the throttle after the front end has tucked in, in which the car will just pull itself out in a neutral stance.

I went with a C2 because I wanted the pure RWD handling. Many folks here track their C4's and enjoy it just as much.

 

John,

You realize that PSM is not available on the 993. The 993 C4 do not have PSM. I am not a C4 expert. In fact I have been researching and learning about Porsche's all wheel drive system as this is what I am considering to replace my 993 with. I know the all wheel drive system of the 993 is different than the 964 all wheel drive system. I also know that the 996 C4 comes with PSM standard as part of the package (at least MY 2000 and beyond) and that PSM was not available on any 993 C4. Beyond that I do not know whether the all wheel drive system has changed much from the 996 vs. the 993.

Viken is probably the best one to ask on this as he is an expert when it comes to specific differences between the various Porsche models.

 

John,

Before my wife and I bought our '95 993 C4, we were thinking of a new TTQR and thought it was a blast to drive.

We both have always loved 911's. When we looked at the dollars involved, and the fact that the TT was based on the Golf chassis, (not to mention all the mags tests on it) we really started thinking of a 911 again.

We bought our 993 sight unseen and only test drove a 964 C4.

We love it and never looked back. We are sooooooo glad we choose the 993 over the TTQR.

Not sure how the AWD differs from a car with PSM but I did drive a Boxter S with PSM and I like the feel of our car much better.

Just my .02

Were are you in CT.?

 

Speaking from a driveability standpoint, I can say hands down my 993C4S is a better handling, gripping, safer feeling car at speed than an Audi A4 quattro I had.

Clearly, they are two different cars, 4 door sedan vs. sport coupe. But IMHO the AWD system of Porsche stuck better than the A4.

Get the 993. It will turn more heads !!!

KD

 

Keith,

Not to question or disrepect your experiences, but to compare handling, gripping and a stuck feeling at speed of these two cars is not a fair. They are completely different animals. That stuck to the highway feel of the 993 at speed is more a function of areodynamics, chassis tuning, tires, and suspension than the AWD system.

The A4 in factory stock trim is much softer and the suspension not near as capable as a 993C4S with a stock suspension. The C4S suspension is much more suited for high speed driving. Not to mention that at speed under dry conditions the suspension, tires and chasis are going to dictate more the handling characteristics than the AWD systems. The suspension tuning, weight distribution, tire sizes and types and chassis charactertics, of the two cars make it virtually impossible to fairly compare the capabilities of the AWD systems.

To really compare the AWD systems you would have to limit the variables and throw in adverse conditions. Realise that the A4 Quattro system acts more like a front wheel drive car under dry conditions and the C4S has more rear wheel drive characteristics.

 

Rezal, Thanks for the comments,

Bet, yeah, I know PSM didn't come until after the 993. My question about PSM was more for "Trivia" than anything else, since I'm really focused on the 97-98 C4.

Evan,
I'm in Norwalk. Good to see another CT-er. I've had my 02ttQR from new and have really enjoyed it. I've had no problems with it (though my dealer in Greenwich is an a$$.) It's been great and I'll be sorry to see it go. How about this though...I actually used the argument with my fiancee that the 993 was a practical choice since it had back seats!

I wasn't so much looking for a comparison between cars, but more of a "I know how the Quattro makes the car behave relative to its handling characteristics, so how does this compare with how the awd changes the handling of the C2 vs the C4, since I'm still deciding.

 

John

When your ready for an independant wrench, let me know.

Oh ya, if you need any help "exercising" your new find, I would be glad to help.

 

Evan,
Are you a pro or shadetree? ANy opinion on Speedsport in Norwalk?

Know of any 2S or 4S's around for sale?

 

John,

How about a "shadetree pro". I know way more on my 914 than the 993 so far.

I have meet Spencer from Speedsport. He's a real nice guy and always willing to help out. I first meet him at a DE at Limerock.

Dan Jacobs at Hairy Dog Garage is closer to me and I have had very good luck with Dan. I would highly recommend Dan. Although Spencer is right in Norwalk. IMHO, Spencer seemed to be a bit more $$$ on some items we discussed. On the other hand, Dan has always treated me fair and his rates are REAL reasonable. He sometimes doesn't even charge for some stuff he does.

Don't know of any "S"'s around, but will keep my eye out for you.

 

John,
I can say that the Audi quattro system is really remarkable in the snow and rain. To match it, you'd need a high clearance and narrow tires on the Porsche. Unfortunately, I own a C2, so my basis for comparison is flawed. However, both cars you are considering really require modification to make them what they should be, IMHO. You can make either one tame or wild. I wouldn't make my decision on the utility of the AWD systems. I'm sure they are both more than adequate in most conditions with the appropriate tires, and worthless in icy conditions, or if you drive on the edge in bad conditions. You will learn to love either car you buy, and occasionally regret the features you gave up. I'm lucky to have both, but the P-car is hard core ( the way I've set mine up, anyway), and you'll need a passion for it to make it your daily driver in CT. ( I used to live in Wallingford). Having said that, the Porsche would be my choice
So many great rides, so little time......

Chuck

 

Chuck,
I think JohnJL was comparing between a C2(S) and C4(S), not between a p-car AWD and a quattro.

John,
Why don't you drive both a C2 and C4? Since you're just starting your search, you have ample time to try several examples of both, perhaps in different weather conditions, and get a feel of for both.

 

Rezal,
You're right, I'm really deciding between the C4 and C2. I am curious about the engineering differences and performance differences between an AWD system I know well and one I don't really know at all.

I was also laughing about the different opinions and thought it a worthwhile post, as it was my first after a few months of lurking on the site.

Unfortunately I haven't had a chance to drive many C4s yet, and none in any rain. I've only had 1 C2 out, and it was with a very nervous salesperson.

Any volunteers offering up their steeds!?