8 cylinder front engine iconic vehicle
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By mr928
#35880
http://shop.928intl.com/Rocker-Bar-For- ... 1-085-00P/
here is feedback from the first customer who installed them

The new passive rear-steer (Kinematic, toe-control) bushes make a huge improvement to the GT's handling, stability and civility in any type of corner or (surprisingly) straight-ahead, and on any kind of road surface or undulation/bump/ridge etc. The car wasn't noticeably bad in all those areas before but the rubber was 30 years old, and I know what improvements new rubber makes elsewhere in suspension components, both on this and other Porsches from the same era, so it shouldn't really be as much of a revelation as it is.

You know how sometimes you're not really aware of something degrading gradually, until it is brought back to 'new'? That's basically the realization I had as I drove the car with the replaced bushes. Right away, on the first freeway on-ramp (a long, open curve, one I know very well) I was surprised by the feeling of the outside rear tire toeing-in. It had never done that in the five years I've owned the car. It felt way more stable through the entire corner, from turn-in through apex to exit. It caught me by surprise, initially, because I wasn't expecting this kind of noticeable, positive difference.

When Greg removed my old (original) bushes, they weren't bad looking at all, no cracking and far less 'concave' on the visible inner rubber flange than others I've seen (the left hand side was more concave than the right - guess I have more fun in right hand bends on any given day). So I figured my Kinematic Bushes were probably in fairly good shape, but they obviously were not.

The driving experience is now positively transformed, and this is a win-win with no downsides: road-noise and harshness are greatly reduced at the rear; the car now holds its line effortlessly in both straight-ahead (one finger steering at speed) and in real corners or high-speed freeway curves - even over bumps that cause the kind of compressions and extensions that will find the limits of suspension travel (regardless of how full the gas-tank is).

I didn't realize how much unmitigated 'squirm' there was over surface bumps, whether straight ahead or in a corner, and how much almost unconscious correction I was applying at the wheel, until suddenly I wasn't having to do that any more. Previously, I just figured we have bad freeway and street surfaces here, and suspension in any car has a hard time with the big deflections...

Restoring the Kinematic Toe function is fairly understandable, but I guess the other factors that have improved are due to the improved location that the new rubber provides: I'm no longer getting seemingly random rear-toe changes (in both directions) as the suspension moves.

For data purposes: the GT is still running the same 8 and 9x16 Clubsport wheels with Michelin PE2 225/50 and Pirelli Rosso 245/45, on your Eibach lowering springs (progressive rate) and reasonably fresh Bilstein HDs all round (less than 10k miles on the rears, around 20k for the fronts).

I know these bushes were either prototype or first article, but if you don't need them back for further testing I'd really like to keep them on the car. Please let me know what I owe you..!

Best regards, and have a good weekend,
ladybug83 liked this
By worf
#35931
YES!

I need four of those.
By worf
#35934
Core required?
By worf
#39159
Thanks Mark!
These look and feel like really good parts.

Yummy:
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By linderpat
#39333
Damn. So many ways to make our cars virtually new again. Just need $$$.

Thanks Mark!
By Tony
#39527
worf wrote: Thu Dec 03, 2020 2:49 pm Thanks Mark!
These look and feel like really good parts.

Yummy:
When the time comes, can you do simple play by play on removal of the old ones....plus installation. In reference to setting up a press. :beerchug:
By worf
#39530
Tony wrote: Fri Dec 04, 2020 4:10 pm When the time comes, can you do simple play by play on removal of the old ones....plus installation. In reference to setting up a press. :beerchug:
I will plan to do so.
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