The factual bit:
As many of you know, I spent many hours down at Star Performance two days ago…12 hours in fact (08:45-20:45) having a play, testing a few things, having a load of work done, trying out a few things etc.
Firstly, thanks to Jim & Brian…12 hours and two meals later we were all knackered!
Credit where it’s due…anyone looking for decent service, advice and standard of work could do a lot worse than giving them a shout.
Secondly, none of this was free…labour rates, wheel alignment rates, dyno time, replacement parts…all paid for out of my pocket...I have the invoice for over Ł900 to prove it!!
Thirdly, these are our (mine, Jim’s and Brian’s) observations based upon our findings. All testing carried out with conditions kept as close to previous conditions as possible etc…some will disagree violently, some will agree…that’s your prerogative.
Now we're getting into the juicy stuff...ARBs!!
A bit of background info:
S3 anti roll bars are as follows:
19mm Front, 15mm Rear (mine are anyway)
Not a bad balance...still understeers...but managable - just!
Out of interest, early TTs - you know the ones, the ones that actually handled but people complained they used to pop the back out if you lifted off in a bend at 130 MPH - had the following: 19mm Front, 15mm Rear
Same as my S3.
Late TTs -after the factory had buggered up the handling - have the following sized ARBs: 20mm Front, 14mm Rear
Now anyone who knows how ARBs affect a cars set up will confirm that normally, the larger the front bar, the more the understeer. And, the smaller the rear bar, the more the understeer. Late TTs have a larger front (more understeer) and a smaller rear (even more understeer)...which may explain why they feel so bad to drive (they do to me anyway!)
...anyway, I digress.
Back to ARBs...
To me, what I want to do is limit the roll of the chassis without going too extreme on the spring / damper rates...as explaines in Pt7 I now have the Bilstein dampers and H&R springs, neither of which are overly stiff.
So, fitting larger bars F & R will limit roll...the dampers are still fit to control them...but the car still understeers...what to do?
Well, the answer is to fit a larger front and rear bar, but to ensure the rear bar is proportionally larger than the front.
I trawled through ETKA and found a 21mm F ARB available off an early A3 1.8Tq...but no proportionally larger rear bar...but what's this in the Neuspeed catalogue?
22mm Front, 19mm Rear
Hmm...3mm thicker on the front and 4mm thicker on the rear.
Now, if my memory regarding ARB twinting forces serves me well, a 2mm thicker bar = twich as stiff as the original...4mm = 4 times stiffer and 6mm = 8 times thicker...I think that's correct (square rule and all that!)
So a Neuspeed 22mm front bar is somewhere around 3 times stiffer and the rear 19mm bar 4 times stiffer.
...the problem being that the ARBs are listed for a TT.
Neuspeed also offer a 25mm front ARB...what's that all about! Understeer city!
Forget that...that'll make it understeer even more...I'll stick to the 22mm bar.
I gambled (not so much of a gamble really...ETKA shows all the clamps, bolts etc to be the same between TT & S3)...and with much help from the kind chaps at Awesome GTI Store, I obtaind the Neuspeed 22mm / 19mm combination.
So, they are on:
Rear...not too bad a job: drop the exhaust, heat shields etc, disconnect the ARB drop links, change the bar, bolt it all up.
Front...nightmare! Power steering rack off the subframe, balljoints off, ARB drop links dissconnected front subframe completely removed from the car, change the ARB...and get it all back together...not an easy or quick job.
But they are on...and combined with the dampers, the handling is a revelation!
Less body roll, and best of all...it turns in like a proper drivers car should, crisp, predictable...the front grips well with no noticable understeer at any detectable speed (not tried it in the wet yet). I like it.
More details on chassis tweeks to follow in Pt9!!