Originally Posted by bmwtye

Im curious how a stock gt3 suspension, with maybe upgraded springs, and the DSC and 3-axis accelerometer would be in comparison to the Bilstein Clubsports

Originally Posted by Tom-TPC Racing

The Clubsports just aren't that popular around here so I don't know. During the David Murry Track Day events at VIR, Road Atlanta, and Sebring the times are within a 0.5 sec of similar cars with adjustable shocks, all cars on Hoosier R6.

PS- My boss does want to put the rear hat kit in production after driving my car just now. He's a pro race driver, he said he can feel the rear shocks working better since the shocks aren't wobbling in the elasto foam rubber during compression and rebound.

Originally Posted by Tom-TPC Racing

Revalving a "sealed" shock for stiffer spring involves changing shims and/or piston to produce a certain dampening curve to control the oscillation of the spring. This procedure is desirable when the force of a spring is outside the control range of a specific valving arrangement(shims/piston design). But stiffer doesn't necessarily mean more tire grip. Adjustable shocks, such as JRZ, have a much greater control range than a sealed shock. Typically a JRZ RS Pro have a range suitable for say 400-1200 springs, which is a very wide range. DSC is fully active And have the dynamic range beyond this to cover as much spring as you would ever want in a 997GT car! DSC range shadows over many adjustable shocks. The dampening curves are demand based. So the driver is not stuck with a stiff ride when there's little to no input(again, stiffer valving doesn't always equal to more tire grip). The input includes brake line pressure, steering angle, vehicle speed, g-force. All this data is in CAN. The .1 cars need a better accelerometer but the .2 car already have it. The algorithm of DSC is written as such that it shapes the dampening curve of the individual shock for real time situations for optimum grip. For example, trailbraking will stiffen up to outside front proportionate to the vehicle speed, brake line pressure, etc. Straight line heavy breaking will stiffen both front shocks to reduce dive(which also reduces front end toe steer). The 600/800 is well within the control range of DSC and for the stock PASM shocks. DSC has three different modes, the modes are switched via the PASM button. All modes are fully active with the difference in mode being the peak stiffness. Sorry if this confused you even more.

The developer will make a video seminar. I will document my installation but I'm going to steal the show from the developer.

Originally Posted by Protocav

This makes complete sense, and after reading it I re-read a detailed Porsche GT3 brochure that I have that describes the PASM system. Even though I knew the "A" in PASM means "active" I honestly didn't put 2&2 together that my stock suspension is already active. Duh. So the DSC is a better controller, than the factory PASM "active" controller that has finer resolution and allows for more range (spring rate). Sounds like the exact module I need to pair with my stiffer springs.

Please keep us updated on this

Originally Posted by Jamie_GT3

I think this is a prime opportunity for TPC to put a kit together with the rear trailing arms, necessary mods to the hats to run the Tarret shock mounts, springs and DSC kit together.

I think we'd see quite a few aftermarket suspensions going back on the market if the stock PASM system could be used well for track/street or even all track setups. As changing the setup on the shocks requires some effort, if the PASM button could control a range of setups, then finding the best setup for each track would be somewhat easier...

And with the drivers mentioned preferring the "bending the car into the corner" style, I think we can all try to adjust our driving to accommodate...

Very interested...

Originally Posted by Tom-TPC Racing

I will give some details but not all because every race team should keep a trick or two...

Alignment
The camber requirement will vary for different tires so there's not one magic number that's good for all. Some people tune camber by how the car feels, while some tune camber by tire temp, and some just do what the tire dealer/rep tells them what camber the tire needs(which may or may not be ideal for whatever suspension is on the car but the tire people usually aren't responsible for rest of your car, just the tires). This is my basic alignment for a street/track car on popular streetable tires.
Front Camber -2.5 deg
Front Toe -0.5mm
Rear Camber -2.0 deg
Rear Toe +2.0mm

Bumpsteer
This is an interesting and lengthy topic. On my car I use TPC Racing adjustable rear toe links to adjust(reduce) bumpsteer. Its not only because I work here, its because the outter pin that goes into the upright is "almost" exactly the same as the latest version of .2 Cup car. So why not just buy the Cup car links? 1) they are $$$ 2) they are $$$ and 3) they only offer one size spacer which is fine when you are using Cup uprights, subframes, and Cup ride height. TPC links come with different size spacers to accommodate for any combination of street and Cup parts, and various ride height ranges. By changing the arrangements of the spacers for a specific ride height the toe curve(toe deviation) changes as the suspension travels. This has a direct impact on rear stability going over bumps and on/off the gas. Bumpsteer is also influenced by the pivot point of the rear toe link, which is the eccentric bolt in the subframe. I set mine in the middle(bolt-head at 6 o'clock), and also influenced by adjustable thrust arm bushings(if adjustable). Thrust arm bushing adjustment changes the angle of the upright, the upright doesn't travel up/down, it travels at an arch pivoting off the point where the thrust arm connect the body. Rotating the thrust bushing in the control arm will change the size of the arch which changes toe curve. We have experimented to such a degree that we can actually dial in the amount of corner exit push to increase rear grip. I run this car's arch at about 6mm wider than stock(which consequentially increases the wheelbase) and put both spacers below the joint with eccentric at 6'clock for minimum toe deviation throughout the entire suspension travel. This mean rock solid rear grip. On my previous 997 with very similar suspension I used the thin spacer up and thick spacer down. Every car will be different due to variables but you can minimize the setup time by duplicating someone else's effort using the same parts.

And here's the shameless plug of the day- TPC Racing toe links use super kickass hi-end Aurora bearings!

Originally Posted by manuxc

Tom, many thanks to share your knowledge ;-)

for a 100% track use with slick, what value would you advise ?
about toe value, is-it for both wheel or by side ?

for bumpsteer, did you check car rear behavior / spacers ? I mean what value can make the most "predictable" feeling ?

reagrds
Manu

Originally Posted by Jamie_GT3

I think this is a prime opportunity for TPC to put a kit together with the rear trailing arms, necessary mods to the hats to run the Tarret shock mounts, springs and DSC kit together.

I think we'd see quite a few aftermarket suspensions going back on the market if the stock PASM system could be used well for track/street or even all track setups. As changing the setup on the shocks requires some effort, if the PASM button could control a range of setups, then finding the best setup for each track would be somewhat easier...

And with the drivers mentioned preferring the "bending the car into the corner" style, I think we can all try to adjust our driving to accommodate...

Very interested...

Originally Posted by Tom-TPC Racing

I did bumpsteer correction using TPC adjustable rear toe links and the included spacers. And I took the correction a step further by using adjustable thrust arm bushings. Your answer here is Yes it made the rear of my car "feel" more predictable, because it is more predictable as a result of increased rear tire grip. If that is what you are seeking you can duplicate my setup.

I am afraid the other answers you are looking for are Race Team-Client Privilege info.

Originally Posted by Mvez

Rear bumpsteer correction/minimization is kinda my last step in my suspension preparation. I have toe links, but will check to see which bump-steer tie rod ends will work with what I already have. I'm hoping yours will work, but it looks like you only sell them as a whole kit.

I run the stock thrust arm bushings and have been tempted to fill in the gaps with some polyurethane to further stiffen them up, like people do for the transmission mounts. I would think this would help, short of installing solid/adjustable bushings.

I still run the stock rear upper shock mounts (with Ohlins DFV), and I honestly can't complain about them. I know they seem to allow more side to side movement, as opposed to vertical compression under load, but I know it's not ideal for ultimate performance. I was just too lazy to piece together a solution as you did, perhaps I'll look into it further now.

Originally Posted by bmwtye

Great news on putting the rear hat kit in production. Please keep us updated.
You mentioned the DSC is controlled by the PASM button so does that mean on gauge display we will see the different names of the different modes (like how now we see pasm normal, pasm sport)

When can we expect the DSC and 3-axis accelerometer ready for us .1 GT3 owners? Will this be offered separately or paired with a kit of upgraded springs/rear hat kit. And what ride height range is acceptable for us to run with the DSC controller.

Originally Posted by bmwtye

When can we expect the DSC and 3-axis accelerometer ready for us .1 GT3 owners? Will this be offered separately or paired with a kit of upgraded springs/rear hat kit. And what ride height range is acceptable for us to run with the DSC controller.

Originally Posted by onefstm

.1 GT3 friends,

Having known Tom through the purchase of their supercharged 993 prototype car 8 years ago, last year in May (2013), I talked him into selling me the DSC box for my .1 GT3, after meeting someone at the track with one on his .2.

Until this thread, I had no idea that I was missing a sensor that was on the .2. Since last May, I have tracked it 5 times. Combined with a Guards diff, this is the best and most enjoyable track car that I have ever owned. Their are three distinct modes which are identified with blinking lights on your DSC button. The base setting is much stiffer than the standard setting on the .1 and even with stock springs, I no longer feel that the car is way too soft for the track. This was something that I felt the first time I tracked the .1 without the box.

Once TPC starts selling the upgraded rear mounts, I will upgrade mine and also upgrade the springs and probably the rear toe arms at the same time.

So, in summary, TPC offers a box for .1 cars now which is definitely a nice upgrade over the stock unit. I have been using it on the street and track for over a year.