GF Test: Sports suspension for the A4

[Tom Nas <tnas@euronet.nl>]

Hi all,

As promised, this is a translation of the test in Gute Fahrt (German
magazine concentrating on VW/Audi) 2/98 of several sports suspension setups
for the Audi A4.
I've somewhat condensed the article, and hope that everyone realises that
neither German nor English is my native language- my 'on the fly'
translation could be somewhat hard to read sometimes.

________
In this test, four sports suspension kits and one spring kit are judged
against Audi's original sports suspension. Gute Fahrt tests Bilstein,
Eibach, H&R, Koni and Sachs. The test shows: lower doesn't equal harder.

Handling test
On a marked circuit, several quick and slow turns have been set up, and the
lap times are measured for each setup. Two test drivers each rate turn-in
response, steering precision and dynamics as well as braking and traction.
Both this and the lap time are used for the final score.

Slalom test
The slalom test with the usual traffic cones setup with 18 metres in
between was also timed. On top of that, roll and pitch were measured. These
tests (as well as the avoidance manoeuvre test and comfort test) were
conducted with both driver-only and car loaded to 80% of its capacity.

Avoidance manoeuvre test
Somewhat like the now (in)famous elk test, a quick lane-change manoeuvre
without braking excecuted to rate high-speed stability was conducted
several times with speeds being raised for every round until the car's rear
end lost traction. In this GF test the speeds can go up to 100 km/h (60
mph) and even over that. The maximum attainable speed of the car in loaded
and unloaded conditions, as well as its handling 'on the limit' were rated.

Comfort test
A good sports suspension doesn't sacrifice too much in the way of comfort.
This was tested on a series of road surfaces, driven at high and low
speeds. Ground clearance was also rated. Like the safety-related items,
comfort was also an important factor in our overall conclusion.

Other tests
The kits were also tested for ease of installation, fit and protection
against corrosion.

Comments
Koni and Bilstein sets were somewhat harder to install because of the
distance rings needed on the rear struts- those for the Bilsteins even
needed some modifications. In the comfort test, the real surprise was the
H&R-equipped car: a lowering of 50mm notwithstanding, the car remained
quite comfortable. Even with a full load, comfort hardly suffered. The only
caveat is that care is needed when driving up a steep ramp of some sorts.
In the avoidance manoeuvre, the Audi setup as well as the Koni, H&R and
Sachs kits did 100 km/h without a problem, whereas the Bilstein kit started
to lose control at 95 km/h in a way which was hard to correct. Even less
pleasant was the response of the spings-only Eibach kit. The combination
with the regular (soft) dampers of the standard suspension turned out to be
quite unpredictable. If you go for the Eibachs, the fitment of firmer
struts is an absolute necessity.
The handling tests showed clearly the two different objectives of the
lowering kits and real sports suspension kits. The low and hard H&R setup
excelled in the timed runs, but the carefully-weighted Sachs kit was only
tenths of a second slower- in front of the Koni and Bilstein kits that
overall equal the factory sports suspension.

		Audi OE	   Bilstein  Eibach Springs	H&R	Koni 	Sachs
_____________________________________________________________________________
Fitting	           ++	      +		    +	         ++	  +	  ++
Quality		    +	      +		    +		  +	  +	   +
Avoidance (empty)  ++	      -		    -		  +	  +	  ++
Avoidance (loaded)  +	      O		    O		 ++	  +	   +
Slalom (empty)	    +	     ++		    O		 ++	  +	  ++
Slalom (loaded)	    +	      +		    O		 ++	  +	   +
Handling	    +	      +		    +		 ++	 ++ 	   +
Steering precision  +	      +		    O		 ++	  +	   +
Body roll/pitch	    +	     ++		    O		  +	  +	   +
Comfort (empty)	   ++	      O		   ++		  O	  +	  ++
Comfort (loaded)    +	      +		    O		  O	  +	   +
_____________________________________________________________________________
Overall rating	very good  acceptable  acceptable   very good  good  very good

Ratings:
++ 	very good
+ 	good
O 	acceptable
- 	sufficient
-- 	insufficient

Hope this table comes out OK (use a monospaced font).

There are detailed pros and contras of each kit in the article, which for
anyone interested I'll try to translate. The accompanying graphs however
are harder to convey via e-mail.

Tom