A Cars forum. AutoBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AutoBanter forum » Auto newsgroups » Technology
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

does anybody besides Audi use the trapezoidal rear suspension?



 
 
Thread Tools Display Modes
  #1  
Old May 16th 20, 02:55 AM posted to rec.autos.tech
[email protected]
external usenet poster
 
Posts: 125
Default does anybody besides Audi use the trapezoidal rear suspension?

I stopped to help a little old lady with a flat tyre. She was driving an
Audi, and I found the independent rear suspension to be quite interesting.
Searching, I can only find SEAT (also part of VW) with it. But theirs
(on FWD ****box) looks like a cheaper implementation of the Audi setup.
Ads
  #3  
Old May 16th 20, 10:25 AM posted to rec.autos.tech
[email protected]
external usenet poster
 
Posts: 125
Default does anybody besides Audi use the trapezoidal rear suspension?

On Saturday, May 16, 2020 at 12:31:45 PM UTC+8, Xeno wrote:
> >

> Supplying a model of Audi would help.
>


It was an A4, less than 10 years old, not sure what year it was.
  #4  
Old May 16th 20, 11:54 AM posted to rec.autos.tech
Xeno
external usenet poster
 
Posts: 363
Default does anybody besides Audi use the trapezoidal rear suspension?

On 16/5/20 7:25 pm, wrote:
> On Saturday, May 16, 2020 at 12:31:45 PM UTC+8, Xeno wrote:
>>>

>> Supplying a model of Audi would help.
>>

>
> It was an A4, less than 10 years old, not sure what year it was.
>

There are two common types of suspension in use today, the vertical
strut type and the double lateral arm type. The A4 uses a variant of the
lateral arm type, also commonly called a double wishbone type. The
advantage of the double lateral arm type, especially at the rear, is
that it is easy to make allowance for a drive shaft and you will see
that on the A4. The greatest disadvantage is that it compromises the
packaging of the vehicle. In this case, the suspension intrudes into the
boot space. Jaguar, with the E Type, avoided the issue by making the
drive shaft the upper lateral link.
https://en.wikipedia.org/wiki/Jaguar...ear_suspension
It was a very clever packaging arrangement and also avoided the need for
a sliding coupling to vary driveshaft length during suspension
deflection. You will also note the use of Hookes type universal joints,
a pair being used to cancel cyclic speed variations. It's not a pure
lateral arm suspension since it uses a trailing arm to control the fore
and aft deflections of the lower link. It's a bit of a hybrid.

Another disadvantage of the standard lateral arm suspension on older RWD
vehicles is that accommodation needed to be made for the drive shaft
length to alter and this was done through the use of a spline
connection. The disadvantage of this with a powerful engine is that the
spline could lock under hard acceleration causing disastrous effects on
the handling. The A4, in common with most vehicles of its ilk, avoid
this through use of CV joints and, in particular, a plunge type CV on
the inner end. The A4 suspension, in common with the type, has a lot of
kinematic advantages. For one, it is easy to build anti dive, anti squat
into the suspension. It is a trapeziod and not a parallelogram because,
if the upper arm and the lower arm were the same length, the wheel track
would alter on suspension deflection. With the shorter upper arm, the
wheel tends to lean inward (negative camber) on suspension deflection
but the tyre contact patch line never alters. Finally, because of the
kinematics, a lot of suspension designs have less desirous traits when
cornering and this can affect rear wheel drives. In some cases, due to
suspension compliance, the rear wheels can toe out under power. That
won't do a lot for your cornering line. You will find the compliance in
the front bush at the inner end of the lower arm is greater than that at
the rear. It is also angled differently to the rear bush. That allows a
slight toe in at the rear which keeps slip angles at the rear tyres in
the *comfort zone*.
The A4 rear suspension has a lot of little tricks built into the design
which won't be apparent to the casual observer but they make for an
excellent handling vehicle.

--

Xeno


Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
A4 B6 Sport Suspension rear toe oddity that keeps popping up in thewheel alignment (rear right) AD[_2_] Audi 0 October 12th 11 01:44 PM
Audi A3 S-line suspension canoe Audi 2 December 4th 06 12:49 PM
Front Suspension Audi A4 Avant 1999 Gus[_2_] Audi 4 September 3rd 06 01:10 PM
Rear suspension E36 steve14775 BMW 0 May 13th 06 04:37 PM
Is suspension covered in audi certified preowned warranty? Wolverine Audi 2 May 1st 06 10:29 PM


All times are GMT +1. The time now is 06:33 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AutoBanter.
The comments are property of their posters.