Steve Weiner-Rennsport Systems

You are correct about that and this will be addressed with the set up I am providing.

Steve Weiner-Rennsport Systems

This is a complex question,.....call me on this one.

In general, urethane bushings are sensitive about fitment since they possess little natural lubricity and they do change shape over time. Unless they are made & fitted properly, they have a lot more friction than a spherical bearing (sometimes even more than rubber) and that's not desirable for good handling.

avddrift

Hoping to be "van der Driftless"

avddrift

Haha, maybe you should try some bacon in Claudia's tank. Might not improve the performance, but the exhaust smell is awesome.

avddrift

Hi Vandit,

Sorry for the delayed reply, i'm travelling at the moment, in Denmark for work.

I am a little in the dark regarding your question, and relying on the expertise of Steve Weiner. What I can say is that my describing the irregular handling to Steve, he eased my worried mind, and understood completely what was going on. Once the upgrades are complete, I will post the results. Although my car is street registered, it spends most time on the track these days, and it is under these circumstances I need the best results. What happens on the street for me is secondary. Although, I think that by locking up the weissach toe correction, I might have to adjust my driving style under different conditions (e.g. off throttle, braking)
as I may have been driving around the variable conditions.

Please note, the monoballs will suit what I do with my car. Last year, I ran the car on 17" rims with Khumo twin grooves, but this year on 18" wheels, I can run wider rear rubber than the car has ever had, and seems more grippy, hence greater forces on the old rubber joints. As discussed with Steve also, the car is now 23 years old, and rubber has a certain life. Time for a change.

I have attached a photo showing the sideway forces at play on hard cornering. I love this shot, as if you look closely, the rear tyre is off the ground too. I can only think that in 1989, on 16" street rubber (as the car was designed), these lateral forces would not be on zee drawing board.

Cheers AvdDrift

KaiB

Interesting pic. Makes for a great shot, but unstable car, does it not.

By comparison, here is C. at high G force, planted down, throttle is being fed in right as the pic was taken.

avddrift

Wow, thats planted. I have a way to go, but thats what I need. Cheers KaiB.

KaiB

Just imagine how you'll go without "fizzledorfing" mid-corner.

We fizzledorf, but power on at exit - loose is good!!!

Babalouie

Yes but "Van Der Understeer" just doesn't have the same ring to it

Vandit

Any updates and results to share?

avddrift

Hi Vandit,

Again sorry for the delayed response, but again I am travelling, and had no time to respond.

The bushes, droplinks, spring plates and new setup was installed on my car. I took the opportunity for a shakedown, and felt the car was a lot tighter, but not where I wanted it. I wasn't happy with the stance, and straight away dropped the height a few turns, and straight away felt a more planted position on the track.

Next competition track day at Norwell was a success, and topped my class, as well as the class above, as well as toppled a few GT3's and a GT2 in classes above. I am on R'Spec Yokohama's, which is a rule to hobble in certain classes, so i'm pretty chuffed. Here is a link to the results: http://www.pcqld.org.au/PorscheClubs...257AA7003B5A09
The down side is that the setup was still not correct. The tyres were well used, but the wear pattern was all wrong. The outside edge of the tyres, especially the left front was totally worn.

Next stop, Morgan Park for the final round of the Motorsport competition. I had the setup changed again, but this time way more aggressive camber on the fronts, as well as lowered again. The sloppy tale was virtually gone, and the uncontrollable weissach slip seemed well improved. The down side is that now I think it has shown inefficiencies in the shocks and springs. My PB on the Morgan Park long track improved, and I have dropped nearly a second from my previous run. But I think there is more in it. I have posted a couple of videos on Youtube with the GoPro stuck behind the right rear wheel. It might be me, but for a track car, it looks like there is too much travel in the suspension, and more of a concern, it looks like there is deflection in odd directions of the back wheel. It is not a normal camera position, and although the deflection may be normal, it would seem to me that it may cause irregular geometry changes. Any thoughts on this will be much appreciated. Tyre wear is now more even accross the tyre too.
https://www.youtube.com/watch?v=stxI...s&feature=plcp
https://www.youtube.com/watch?v=b_MU...8&feature=plcp

Kind Regards,
AvdDrift

Vandit

What was your final parts setup? What bushes, for the trailing arm? ERP spring plates?

avddrift

ERP 964 Front A arm monoballs
ERP 964 Rear trailing arm monoballs and mounting kit
ERP Rear spring plates
ERP Front camberplate/monoball mounts
ERP Rear upper monoball mounts
Tarrett Rear adjustable swaybar droplinks
Tarrett Front adjustable swaybar droplinks

Cheers,
AvdDrift

tkyyro

Well mr Drift, as you seem to have already a perfect taste in music its only fair you're experiencing some trouble on track

avddrift

Scatterbrain gives the feeling of speed, perfect match to a track day video. Thanks for the compliment.