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Why a front anti-roll bar (sway bar) is good for auto-xing

Why a front anti-roll bar (sway bar) is good for auto-xing

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[gti-vr6] New front swaybar (followup) Mike Shields <mshieldsinconnect> Thu, 9 Jul 1998 16:24:31 -0600
Re: A3 - AutoX & Swaybar Question RandyWalixcom (Randy Walters) Wed, 21 Oct 1998 01:29:16 GMT



From gti-vr6-ownerdev.tivoli Thu Jul 9 17:42 CDT 1998
From: Mike Shields <mshieldsinconnect>
To: "GTI-VR6 List" <gti-vr6dev.tivoli>
Subject: [gti-vr6] New front swaybar (followup)
Date: Thu, 9 Jul 1998 16:24:31 -0600
 
Hi all, me again.

I just wanted to follow up on my front bar install and it's effect of the
car's handling. As I told before, the autox performance is much improved.
However I found the other night going to pick up my wife the bar has a
little side effect.

A lot of you have been putting down the Shine setup for the reason that
it doesn't do a lot to counteract the roll of the car. I'm going to tell
a little story to illustrate why the advocate what they do.

On my way to pick up my wife at work, there is a road going up a hill
turning from one city block to another. This hill is a steep and curvy
right, then left. Not quick but fast (50mph is a good fun speed up it).
You get into a good steady state cornering attitude and blast on up it.
With the stock front bar I could get going up it around 55 or so before I
started overcooking the first corner (the right hand, tighter turn). I
was able to get into the turn and then steadily pour on power to blast
through turn 2 (left hand increasing radius). With the new 25mm front
bar, I now have to go into the corner slower and have to wait almost
until the end of the turn to get onto the power. I end up going about
5-10 mph slower by the end of the two turns than I did before. (Can you
imagine the difference if this was a race and that happened??)

Basically what I'm trying to say is that I know why Shine has always
argued against the front bar on our cars. They are road racers - faster
turns where steady state cornering speed is much more important than
transitional reponse like an autox. By using a big front bar, you are
making the initial turn-in quick and decisive. Great for an autox where
by the time the car is to it's steady state, you're probably starting the
next turn the other way. On a road course where you go into the turn and
stay there - bad, bad. All of a sudden all the things you read about
suspension tuning comes into play in a big way. I originally went with
the Shine setup because it agreed with everything I know and had read
about suspension tuning. I was a little disappointed when it didn't
perform like I wanted in the autox. Great on the street, not so good in
the autox. Looks like I now have a choice.

It looks like what I'll do when I go to one of our Solo Trials events is
bring along the old front bar and swap it back in (or maybe just try
disconnecting it) and see how it goes since there is a lot more high
speed turns where the suspension settles down and corners more like road
racing.

I'll keep you al up to date (if you're interested)

Mike

-------------------------------------
Mike Shields
SCCA Utah Region Webmaster
CSP #54 VW Jetta GLX
<http://www.team.net/urscca>


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From
From: RandyWalixcom (Randy Walters)
Subject: Re: A3 - AutoX & Swaybar Question
Date: Wed, 21 Oct 1998 01:29:16 GMT
Newsgroups: rec.autos.makers.vw.watercooled
 
psb <advantnb.sympatico.ca> wrote:

>I have a 96 GTI 2.0l that I use to autocross frequently during summer
>months.  At this point I'd like to stay in the stock class which means
>that I am very limited in what I can do to the car.  I am thinking that
>putting the largest sway bar I can find on the rear would be a big
>benefit. I've always read and heard that you should have the bigger
>swaybar on the end that sticks best. Since my car is an inherent
>understeerer a larger swaybar on the rear should help significantly.

 For normal cars a rear swaybar would help prevent understeer, but
many FWD cars' understeering tendancies are *reduced* with a bigger
*front* swaybar,  and VWs are one of em especially when they have
stock springs.  The reason a big front bar works on a VW is that it
helps keep the front of the car flat which in turn keeps the outer
front tire from going into an extreme positive camber attitude and
that keeps that tire's contact patch flatter on the pavement where
it can actually do some good.   As it is now your outer front tire is
being pushed over onto it's sidewall when it's plowing and the
tire is being severely distorted and overloaded so it can't do it's
job.  For your car i'd install a 25mm Neuspeed front swaybar.
I assure you the car will corner harder,  slalom and transition
faster,  stick through the corners better, and be a lot more stable
overall.

 There will undoubtedly be people who will jump in here and dispute
this but i can tell you this is established fact in the autocrossing
world among the fastest stock class VW autocrossers and has been
for years.  All the VW roll control is determined at the front of the
car where all the weight is and where all the work is being done.
The rear is only along for the ride in comparison and adding a
swaybar back there does almost nothing to improve handling on
a stock-sprung VW,  it just pulls the inside tire higher off the
ground in hard cornering and slightly reduces the outer rear tire's
contact patch as a result but any handling improvement is slight
if anything.  Concentrate on improving traction up front instead of
reducing it at the rear.


>Are there possibly some other things I can do that would provide a great
>benefit that won't knock me out of "Stock".  I am in Canada, so U.S.
>rules may not apply.

  I don't know how or if your stock class rules compare to the US SCCA
rules,  but here you're only allowed to change the front swaybar in
the stock classes - we're not allowed to mess with or add a rear
swaybar whatsoever which is fine by me.  We can also use any
DOT approved race tire as long as it's on a stock sized wheel,
and we're allowed a 1/4" wheel offset variance from stock specs.
We can use any shock, any brakepad, any cat-back exhaust,
any air filter,  and a few other things here and there.....  and
don't forget tire pressures (extremely important).


>I would like input from people who can speak from experience please.

 I can and have.  I've been autocrossing my 85 GTi for years and
have tried many combinations of spring,  shock, and swaybar setups
and i know from vast direct experience (my own and my friends')
what's fast and what's not.  My DSP GTi has carried me to five
San Diego region DSP Championships (93 through 97) and i'm
leading this season in SD too.  In the Los Angeles region i've been
the runner up to former National Champ Tom Berry until he got moved
to CSP,  now i'm the leading DSP car in the L.A. region by default :-)

I even headed 400 miles north to the San Francisco region and was
the fastest DSP car there at a recent two-day autocross last Oct 3-4

( see:   


 I also have an 86 Jetta GLi street car that's prepared to E-Stock
specs,  and the simple addition of a bigger front swaybar completely
transformed the car's handling from terminal understeer to oversteer
on command and the car got WAY faster immediately.  I've gotten
several stock class VW drivers to use a big front bar and every
single one of em was impressed with the improvement and soon
were going a lot faster especially after they fine tuned their tire
pressures and modified their driving techniques to suit the
newfound front cornering traction.  It simply works and nobody
who knows what they're doing will tell you otherwise :-)  I'm
not trying to brag but i'm just stating the facts as an experienced
VW performance driver, autocrosser, and suspension fiddler :-)

 Randy Walters
 85 Golf GTi DSP
 86 Jetta GLi ES
 So Calif SCCA










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