PSi/Ohlins TTX Porsche CGT Suspension system
12-15-2012, 04:40 AM
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PSi/Ohlins TTX Porsche CGT Suspension system
Anyone with first-hand experience they would care to share? I'm particularly interested in a) off-camber rear-end traction & other noteworthy handling changes relative to the stock setup, and b) the fit & quality of fender liners. Either a PM or forum response would be great. Thanks.
12-17-2012, 09:51 PM
#2
Yes, worth every penny.
We worked with Bruce & Co. from PSI on their first TTX fitment, from which they developed their current turn-key package that we installed on a second CGT. The difference is tremendous.
For starters, we've found that most OE Sachs dampers have begun to leak with time, losing their nitrogen charge and hydraulic oil (and performance). Run your fingers under the rears and see if you come up wet (or remove the front fender liners and look for a trail).
Second, and far more importantly, Ohlins' single piston/twin-tube damper system is truly state of the art. It allows for much more accurate control, adjustment, and consistency. Not to mention the internal design is more durable, with less side-loading of the damper shaft (unlike the Sachs units). And they are easily serviced in North America should you ever manage to wear them out.
Finally, the performance is unreal... not that the CGT was ever a slouch to begin with, but the Ohlins package truly brings it up to contemporary handling, comfort, and control levels. When PSI setup the first set they took measurements of sprung and unsprung weights at each corner, along with plotting leverage ratio and curve of the pushrod/bellcrank system, then used that data to calculate spring rates and damper tunes. Once they were done they dyno'd a stock damper for comparison (AFTER plotting their own from scratch). The stock setup fell right in the middle of the Ohlins' adjustment range. And with adjustable rebound and compression (we settled on two adjustments - they can go from preset to five-way depending on your preference) you can dial the ride from go-kart stiff (with control) to supple... or as supple as something like a CGT can be anyway!
Re: PSI, these are world class suspension experts in every sense of the word(s). They know EXACTLY how to set up dampers, and the carbon tub of the CGT makes for a perfect stage to showcase their capabilities due to its inherent rigidity. Without body flex to contend with the dampers can be fine-tuned to perform exactly how you like, consistently. And they have all the data necessary to deliver a turn-key package, including the most beautiful carbon fender liners you've ever seen! It's a shame that they're hidden once installed, they blend so well with the rest of the car's construction, but fit & finish is top notch.
Our second install arrived preset and ready to bolt up as-is; they now have the tuning data from the first car, so when it came time for another set they had everything dialed. We installed them without touching a thing and the ride heights came into spec within one millimeter at each corner, no exageration. And after several hundred miles of road use our personal favorite settings have the compression at about five clicks from full soft (out of twenty) and rebound approx mid-way. This gives the car exceptional comfort and straightline traction (feels like Velcro when you lay on the power, as opposed to the skipping/hopping gyrations of the stock setup) while still maintaining fantastic cornering control. And that's with the sway bars set mid-way.
I am not a fan of aftermarket equipment in general, especially when it entails second-guessing the engineering of something as poured-over as the CGT; however, in this case there is no denying that this particular modification is a dramatic improvement over the technology and components that were available at the time of production. Moreover, in this (rare) case the chassis itself is being held back to some degree by the original equipment, and the new & improved kit... really is!
Important note: PSI's settings and calculations at least in our cases have been based on cars with stock wheels and PS2 tires, and AWE straight pipes (and therefore approx 90lbs less weight hanging off the rear axle). Be sure to make Bruce or Beau aware of your car's setup if it varies... or dump the stock muffler. The sound... oh the sound...
Feel free to hit me up if you'd like further details, and good on ya' for shopping PSI - they're a class act through and through. Good luck!
For starters, we've found that most OE Sachs dampers have begun to leak with time, losing their nitrogen charge and hydraulic oil (and performance). Run your fingers under the rears and see if you come up wet (or remove the front fender liners and look for a trail).
Second, and far more importantly, Ohlins' single piston/twin-tube damper system is truly state of the art. It allows for much more accurate control, adjustment, and consistency. Not to mention the internal design is more durable, with less side-loading of the damper shaft (unlike the Sachs units). And they are easily serviced in North America should you ever manage to wear them out.
Finally, the performance is unreal... not that the CGT was ever a slouch to begin with, but the Ohlins package truly brings it up to contemporary handling, comfort, and control levels. When PSI setup the first set they took measurements of sprung and unsprung weights at each corner, along with plotting leverage ratio and curve of the pushrod/bellcrank system, then used that data to calculate spring rates and damper tunes. Once they were done they dyno'd a stock damper for comparison (AFTER plotting their own from scratch). The stock setup fell right in the middle of the Ohlins' adjustment range. And with adjustable rebound and compression (we settled on two adjustments - they can go from preset to five-way depending on your preference) you can dial the ride from go-kart stiff (with control) to supple... or as supple as something like a CGT can be anyway!
Re: PSI, these are world class suspension experts in every sense of the word(s). They know EXACTLY how to set up dampers, and the carbon tub of the CGT makes for a perfect stage to showcase their capabilities due to its inherent rigidity. Without body flex to contend with the dampers can be fine-tuned to perform exactly how you like, consistently. And they have all the data necessary to deliver a turn-key package, including the most beautiful carbon fender liners you've ever seen! It's a shame that they're hidden once installed, they blend so well with the rest of the car's construction, but fit & finish is top notch.
Our second install arrived preset and ready to bolt up as-is; they now have the tuning data from the first car, so when it came time for another set they had everything dialed. We installed them without touching a thing and the ride heights came into spec within one millimeter at each corner, no exageration. And after several hundred miles of road use our personal favorite settings have the compression at about five clicks from full soft (out of twenty) and rebound approx mid-way. This gives the car exceptional comfort and straightline traction (feels like Velcro when you lay on the power, as opposed to the skipping/hopping gyrations of the stock setup) while still maintaining fantastic cornering control. And that's with the sway bars set mid-way.
I am not a fan of aftermarket equipment in general, especially when it entails second-guessing the engineering of something as poured-over as the CGT; however, in this case there is no denying that this particular modification is a dramatic improvement over the technology and components that were available at the time of production. Moreover, in this (rare) case the chassis itself is being held back to some degree by the original equipment, and the new & improved kit... really is!
Important note: PSI's settings and calculations at least in our cases have been based on cars with stock wheels and PS2 tires, and AWE straight pipes (and therefore approx 90lbs less weight hanging off the rear axle). Be sure to make Bruce or Beau aware of your car's setup if it varies... or dump the stock muffler. The sound... oh the sound...
Feel free to hit me up if you'd like further details, and good on ya' for shopping PSI - they're a class act through and through. Good luck!
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