when did vw/Audi go to the "drive-by-wire" instead of the

ScottyCBoy at aol.com ScottyCBoy at aol.com
Thu Dec 4 18:09:47 EST 2003


In a message dated 12/4/2003 1:24:05 PM Central Standard Time, ti at amb.org 
writes:

> JordanVw at aol.com writes:
> >oh..and in addition to my question of WHEN did they change,  WHY did they 
> >change over to drive-by-wire anyway????   what are the benefits?  it seems 
> like 
> >response is decreased with the electronic throttle vs the old cable type, 
> which 
> >was instantaneous..
> 
> There are many benefits of drive-by-wire.  For example, cruise control
> and idle stabilization and full throttle enrichment no longer need
> additional devices or switches, it can all be done from the ECU's software
> directly.  The rate of throttle closing can also be programmed without
> the use of hacks like dashpots, etc., less mechanical devices means
> better reliability (say bye bye to having to clean your ISVs, or repair
> bad throtle switches, or replace cruise control servos, etc., because
> these all no longer exist).  Furthermore, with the advent of ASR, ESP
> and other electronic assists, the ECU must be able to control the throttle.
> This can only be done with drive-by-wire.  Also, the ECU can learn your
> driving habits and optimize operating conditions (such as making
> auto transmission shift points adapt to your style and make shifts
> feel smoother by making throttle adjustments).  On DSG gearbox cars,
> the ECU will blip the throttle for you to match engine RPMs for quick
> shifting, and on multitronic (CVT) cars the drive-by-wire will optimize
> acceleration *and* economy by choosing the best engine RPM and
> transmission ratio for the conditions. etc., etc.
> 
> Drive-by-wire began around the 2000 model year on the A4, I think.
> 
> -Ti
> 2003 A4 1.8T multitronic
> 2001 S4 biturbo 6-sp
> 1984 5000S turbo
> 1980 4000 2.0 5-sp
> 

Acutally some of the BMWS were able to control engine output by adding a 
second computer controlled butterfly ahead of the throttle plate which was cable 
actuated. Sort of a screwed up setup but it worked well.  Sort of the best or 
worst of both worlds. 

The 1.8T's saw DBW in 2000 and a half. Not too sure about the V6's. I think 
all S4's are DBW.

Scott


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