Jim De Arras

It's missing nothing, you speak from ignorance.

Russ Burns

Ignoring lthe 0-60 starts, one wheel spinning in a corner is desirable. Look at your options.

hard corner, no wheel spin. great.

Hard corner, one wheel spinning, good. You are getting a warning that you are exceeding the traction limits.

Hard corner two front or two rear wheels spinning. You just went off the road.

If you go from no wheel spin, to both wheels spinning due to a LS in an axle , you'll be putting the car in the ditch quite often.

The correct technique is to reduce the throttle to eliminate wheelspin. A LS is liable to just start both wheels spinning.

Take care
Russ Burns

Jim De Arras

Audi Quattro systems (for street cars, at least) have NEVER done that.

Bob

when load bias ratios are not maintained. Moving the spin around can cause more problems than you can imagine. Trust me, I've been building, fixing, and driving/racing Audis since 1980 and have owned many Quattros.

Your "unfair advantage" Quattro Touring car had electronically controlled mechanical multi-plate clutches and driver tunable viscous differentials costing many 10's of thousands of dollars. It was driver tunable because of small variations in track conditions. Why do think the S4 only costs $40K with Quattro and twin turbo's? Torsen and planetary diffs with EDL is an off-the-shelf, well known system that works in the majority of conditions that production cars confront.

Bob
96 A4QM
86 4KCSQM

Stig Blomqvist

A liitle bit wheelspin is no problem...learn to drive NT

Charlie

I put 70,000 miles on an urquattro and have put 30,000 on an A4 1.8Tq sport. The current Torsen quattro system is a vast improvement over the original system and the A4 is by objective standards a better handling driver's car than the urquattro. Yes, I know this is heresy, but the urq tended to be a stubborn understeerer, except when it suddenly chose to snap into liftoff oversteer. Consistently finding the balance and holding a slight 4 wheel drift took me years of practice on snow, gravel, ice tracks, etc. Those beautiful drifts you saw the rally quattros do were controlled by left foot braking (and more rear-biased brakes than the street cars.)With the original system one could experiment with the manual differential locks, but locking the diffs led to even more understeer and then when it broke loose on ice, grip was lost at all four corners. I thoroughly enjoyed the urq and am grateful to have been lucky enough to own such a classic, but it was not quite as invincible as the press (especially British) would have you believe. Also, the brakes (pre-ABS) were nowehere up to the accelerative potential. I remember my first drive in the Colorado mountains in the urq after owning an Audi Coupe GT (front wheel drive). The urq felt sluggish and less tossable.

In comparison, my A4 with quattro IV (torsen and EDL) can be driven very consistently with the throttle in wonderfully stable tail out drift. Terminal understeer is no longer a problem. When I owned the urq, I also wished for a more rear-biased torque split, etc. The A4 with new quattro system, while still 50:50, is a much improved handler.

I haven't had much seat time in an S4. It obviously has more torque than my 1.8T and my US spec urq did, so wheelspin effects are more evident. But if you wanted no wheelspin, buy a BMW with ASC+T that will kill the engine as necessary!

Charlie

Bill D

Evolutions and STI Subaru's don't lack any feel when I'm behind the wheel.

<img src="http://www.rallysport.net/comicozzie/mf99/driegert2.jpg">

.....and in terms of absolute performance there is no question that LSD's are always an advantage...keep fooling yourself but EDL's biggest advantage is that it saves a couple thousand off the sticker price....EDL doesn't transfer power it curbs power to the spinning wheel....that is the simple reason that a mechanical or active LSD will always provide the performance advantage...the "infinite load bias" ratio is a minute advantage of EDL against a long list of disadvantages....give me a real world situation when super high slip ratios are useful between left and right wheels.....

BIll D

to avoid confusion

- EDL is cheaper than 3 LSD's...I didn't mean EDL is cheaper than no EDL
- The car I'm driving in the picture is a U.S. Subaru 2 door shell with all WRX STI II RA mechanicals. It is the same car that Seamus Burke is driving this season.

daphne

Credit where credit is due - Photo by Jerry Winkler

ErikR

Bob and I disagree on a few points, but I believe that in this case you are talking cross-purposes.

EDL is a really good street patch, for a number of reasons that we have discussed on the A4 and the "deleted" posts here.

EDL is a lousy racing system. It works acceptably in AX and track work in an unmodded A4.

Active is the way to go street or racing. So far, it is all R&D payback and quite expensive. No argument. This is the drivetrain evolution derived from rally.

Now, the issue with the rear torsen (etc.) got lost with the HP. For street use the axle bind on dry roads is a drag, it is not really discernable in rally (it is in handling, but see next). What Bob was really reacting to was the torsen up front. He's driven one and dislikes it. I've only driven jeeps with F:R lockers and hated it.