RE: New to Audi's: Basic Questions

[Reiner Fink <reinerf@microsoft.com>]

One of the projects that I want to undertake sometime in the future is
installing manual diff lock switches. Any idea of how hard a task this
would be? I'm guessing that all you need to do is provide the right
voltage at the right place, and wa-la. It would also be interesting to
see when the EDL diffs lock under various driving conditions, so if I
figure out how to monitor the EDL in action, I will definately do that
first. 

Also, is there a Bently available for the A4q yet? (if so, where do I
order it?) Or what about the Alldata cdroms? I really don't care until
I'm out of warranty, but I would like to better understand how
everything works before then.

 -reiner

>----------
>From: 	dan_masi@MENTORG.COM[SMTP:dan_masi@MENTORG.COM]
>Sent: 	Tuesday, October 08, 1996 7:39 AM
>To: 	tlazay@ultranet.com; quattro@coimbra.ans.net
>Subject: 	Re: New to Audi's: Basic Questions
>
>On Oct 8,  9:37am, tlazay@ultranet.com wrote:
>
>> Anyway, I am new to Audi and currently have a silver 97 A4
>> quattro coming in a few weeks from now.
>
>Congrats!
>
>> 1) Electronic Differential Lock: What is this? How does it
>> help? When does it engage?
>
>I'm not entirely sure what the technology is, as I've heard
>two different stories.  Anyway, this is basically what makes
>the quattro a 4-wheel drive car.  In a "regular" car, power
>is sent from the engine to a differential (in the front or
>rear, depending on whether it's FWD or RWD).  The diff then
>sends power to one of the two wheels, right or left.  Standard
>diffs will send power to whichever wheel spins easiest;
>thus, it's a one-wheel-drive car, and worse, the wheel that
>gets the power is the one that's sitting on ice.
>
>An AWD car has two diffs, one in front and one in back; plus
>a center diff.  The quattro uses a Torsen center diff, which
>won't just send power to the "easy" side.  So now, both the
>front and rear diffs have power, and if each of them sends
>power right or left, you've got a two-wheel-drive car.
>
>The diff is necessary because it allows each tire, left and right,
>to rotate at different speeds (e.g. for turns).  But in really
>slippery stuff, and at low speeds, there are times when you'd
>prefer to "lock" the diff... that is, force both wheels to
>spin at the same rate, locking them together and delivering
>power to both.  Do that front and back, and you've got
>true 4-wheel drive.  That's where the ELD comes in.  At low
>speeds, if the A4 detects wheelspin between left and right
>on either diff, it will lock that diff.  I had assumed it
>did it with an electrically-activated clutch of some sort, but
>I've also heard that it does it by selective brake application
>on the spinning wheel.  Anyone know?
>
>> 2) CD Changer: Do you really have to pay the dealer $600 to
>> install a changer that one could install by themselves for
>> $300? Could one install an "off the shelf" changer from
>> Crutchfield or any other similar outfit?
>
>The Audi changer is an Alpine with modifications.  The control
>signals have been altered; there is no off-the-shelf CD changer
>that will talk to the Audi Delta head unit.
>
>There is a company called Precision Interface Electronics (they
>have an 800 number) that has been working on an adapter that will
>allow you to use the standard Alpine changer off-the-shelf.
>As of June, they didn't have the adapter ready for sale yet;
>you might want to check.  As I recall, the adapter was going to
>be somewhere around $100, and the best street price on the Alpine
>changer is somewhere in the low $300's.
>
>Consider, too, that paying $600 for the dealer-installed Audi
>changer also buys you warranty protection for 3 years / 50000
>miles.  I decided to get the Audi unit, and am quite pleased
>with the performance.
>
>Your other option would be to install your own aftermarket
>changer AND head unit.  Be aware that the dash has a wider-than-
>standard-DIN opening, so while a DIN-mount head unit will install
>there, there will be a gap on each side between the faceplate
>and the wood dash trim.
>
>> 3) Tires/Snow tires: Do you recommend snow tires for this car?
>
>I'd like to hear some answers on this, too.  I'm in NJ, and
>even though we had some wicked snow last year, I'm planning
>on going year-round with all-season tires.  I assume that
>the decision to put snows on the car is not so much for
>snow performance, but to allow one to put higher-performance
>tires on in the "dry" months.  I'm not taking exit ramps
>at 80mph, and I think that today's high-performance all-season
>tires are quite respectable for their dry performance.
>
>> 4) Performance Upgrades: Are there any chips or air filters
>> which would increase the 172 hp?
>
>Schaumburg Audi (Chicago) sells a modified throttle body.
>They take the stock throttle body and bore out a restriction.
>It doesn't increase peak hp, but seems to improve torque at
>middle rpm (2000-3000 or so).  It costs about $300.  The
>change is very subtle, but at least it's something.  They
>also recommend replacing the paper air filter with a K&N
>panel filter.
>
>Dan Masi
>'96 A4Q
>
>