Like TTGasman says the the TT has stock braces. Again it's a preference. Like anything else, good aftermarket performance products can improve upon what the factory puts in. Just like the suspension. I wouldn't go as far as Gasman in saying that it's for poseurs and magazine racers. Personally, I am planning on doing one. Ít's really an inexpensive part.

 

Thanks Mike, I understand.

If possible please give report once your suspension setup is dialed in. I am intrigued by the higher (than Bilstein) spring rates you picked and the reputation of JRZ.

I notice your signature says "RSS" sway? RSS now has Turbo sway?

 

The higher spring rates are due to the fact that JRZ uses a helper srping instead of a tender spring. The helper srpings have no tension vs. a tender that has tension on it. If you look at the specs of the Bilsteins, you will see the spring rates on the tenders.

The whole JRZ setup has been a learning experience. We have it base lined and we are just playing with diffrent compression/rebound settings and alignment setups.

RSS now has their own sways. My car was one of the cars used for test fitments. So far, the sways are working wonders through the corners.

When I'm done, you should come by and take it for a spin....

 

I love the picture. How's the ride and can it be dropped a little more?

 

sorry about the tongue in cheek crack about mag racers and poseurs, but I the strut brace is worthless on a street car.

 

Thanks. The official Bilstein recommendation is that ride heights be reduced 10-30 mm front, and 5-25mm rear. Mine is lowered about 10mm. Others with Bilstein lower it to 20mm.

It's interesting that they do NOT recommend stock ride heights. That is, if you are using PSS10, you should lower the car at least 5-10mm.

From my reading & web research (I am no expert, anyone feels free to correct me if needed.): The risk of not lowering is coil binding (springs already compressed at rest, not good). The risk of lowering too much is that you hit the internal bump stop; not good either.
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Can, I believe coil binding is a function of the spring rate and type, linear vs progressive. It's not all bad, even the oem springs on a GT3 coil over "bind" a little. Like anything else, within moderation...
The Bilstein recommendation is interesting. The fear of hitting the bump stops is the same argument some make against lowering springs, I guess it happens with any coil over. My car is dropped 20mm and the shocks have plenty of travel. Again, keep it in moderation. As long as the valving is compatible with the changing spring rates it's not a problem.

 

I re-dropped or raised mine since it was lowered to about 40mm for a while. The looks were great but the handling deminished greatly in places where it counted such as rebound/dampening. I did not hit bump stops per se but I was close. I raised it up about 26mm front and 22mm in the rear and its just right.

I knew when I was lowering it that low it would hurt some but I didn't realize how much it hurt the handling until I really got on it through some mountain roads and it scared me how squirrly the backend got and the rebound was not really too effective through some short "s" turns. Now through the same "S" turns its very confidence inspiring and I think some sways would give me the final touches that I am looking for. I will try it out again soon on 19"s and see if the improvement is that much better than the 20"s. In all logic the 19"s should perform at least 20% better than 20" with the increase in sidewalls.

I am still debating on the drop links or not.

 

is pasm still active or turned off? what are the pros and cons

 

Doug, thanks. I called for Bilstein for these things but because suspension installation is not part of my day job, I always have some doubt whether I understand them correctly.

More details of what Biltstein told me: The PSS10/B16 is a dual/stacked springs setup, main plus helper. The helper, as name implied, is completely compressed at rest. When the main spring starts binding at rest is when problems arise.

Bilstein PSS10 Damptronic
Front 285 Main, 115 Helper
Rear 570 Main, 145 Helper

Yes I agree with "moderation." As much as I don't like the stock suspension setup, I actually prefer to make the least change possible from stock because who knows what else is going with the complicated suspension geometry when we make changes. For now, that is.

 

There are two versions of the Bilstein PSS10's, the version that people use is called B16 Damptronic, meaning it's compatible with PASM. One thing to note is unlike the Stock settings, where Stock Normal is too soft and Stock Firm is so stiff and harsh that it becomes nearly unusable, the difference between Bilstein Normal and Firm settings is more subtle.

On a scale of 1 to 10, if Stock Normal is 1, then Bilstein Normal is around 6-7, Bilstein Firm around 8-9, and Stock Firm is 10. But the numerical designation doesn't describe the difference in dampening quality. Although the Bilstein ride is firm, the ride/dampening quality is vastly superior to Stock Firm.

 

1. Introduction
The anti-sway bar two functions, one is obvious from the name, the other not often discussed but equally important:
A. Anti roll
B. Adjust understeer/oversteer

A is just that, the anti roll bar adds roll stiffness and prevents your car from leaning in corners. Roll stiffness is very important because it keeps the tires in best contact with the road and maximize traction (larger contact patch) in corner. More body roll also unsettles driver and conversely, less body roll subjectively is a major reason for a car feeling "good." You've hear the oft mentioned expression "cornered as if on rail."

B is related to the effect of sway bar on roll couple distribution, an all important concept in understanding car behavior in corners. It has to do with the roll and ride stiffness of the front of the car RELATIVE to the rear of the car, and how this would cause the car to understeer or oversteer. Adjustment of sway bars is used by professional drivers to affect understeer/oversteer behavior of a car. If you stiffen the front, you have understeer (as a result of higher slipped angle of front tires); if you stiffen the rear, you have oversteer (as a result of higher slipped angle of rear tires).

To reduce the inherent understeer/neutral steer of a 4WD car, for a street car, I've softer front and stiffer rear, for example soft setting front and medium setting rear, to be an excellent starting point, but of course this is strictly personal preference, no right or wrong and it also depends on the rest of the suspension components in any particular car.

2. Which sway bar?
Top 2 choices are H&R and GMG. TPC is another reputable product. As far as H&R or GMG sways: I have no idea how they compare to each other with respect to stiffness/performance. The only reason I went with GMG was at the time I was going to go with the whole GMG package (later changed my mind to Bilstein Damptronic PSS10). Also for my peace of mind, I also like very much the fact that GMG is the only company that publishes specs of the bar:
GMG Front Sway: 3 settings: soft, medium, stiff. The front soft setting is 15% stiffer than stock, middle 25%, and stiff 35%.
GMG Rear Sway: 3 settings: soft, medium, stiff. The rear soft setting is 30% stiffer than stock, middle 45%, and stiff is 60%. The GMG bar btw is made by Eibach, one of the "gold standard" companies in after-market springs and bars.

Lastly, you could use 997 GT2's rear sway bar in the Turbo, and keep the stock front (front GT2 sway bar doesn't fit Turbo). Because the stiff GT2 rear bar is supposed to be used with the sitff front GT2 bar, only using the rear obviously will result in a setup that is unbalanced towards the rear; rear is stiff (GT2 bar) and front is too soft (stock Turbo bar). The risk of the imbalance is excessive oversteer, and just the overall uneasy feeling, for me anyway, that you are using something that is not made for your Turbo. Anyway, although I do prefer and recommend replacing both bars, there are people who use GT2 bar and like it,.

Much has been made of hollow vs. solid; I don't think it's that important because this is not unsprung weight. My rear GMG sway bar is around 7 lbs IIRC, 2 lbs heavier than stock. Could you feel whether there is an extra laptop computer in the back of your car? I rest my case.

Sway bar remains the most "mysterious" of suspension components, since no vendor except GMG releases their specs and there is no review "data" so you rely mostly on words of mouth. Were I to buy a sway bar set today, my top 2 choices would be H&R and GMG. No one knows how they compare with each other, or which one is "better," however I will give the slight advantage to GMG because of the reasons above.

3. What does it feel like? The GMG sway was actually the first suspension component installed in my car as I wanted to learn step by step and wanted to find out what it does by itself. To my surprise, I found that the anti roll effect is subtle with the stock springs, NOTHING like the transformation brought on by the Bilstein Damptronic that I was to install later. At the medium settings, body lean is reduced a little, but more importantly, the steering feels tighter. There is less free play to the steering wheel as you rock it back and forth for example.
Once stiffer springs (the Bilstein) are installed, I feel the effect of a sway bar is much more noticeable. Stiffens the rear will reduce understeer/increase oversteer - it's a great educational tool for anyone of us to try out and see for yourself! One negative effect I *have* found is that the rear setting, if at full stiff could affect ride significantly. The rear becomes stiff & very bouncy and for me unacceptably hard when the sway bar is set to rear stiff.
In short, I very highly recommend the sway bar - it is obviously a critical part of the suspension setup, but only after you have installed the Bilstein Damptronic with its stiffer spring. Used by itself with the stock soft suspension setup, the effect is very subtle.

4. Maintenance IMPORTANT!!: My GMG bars come with polyurethane bushing, and a lot of people don't know that unlike stock rubber bushing, after-market polyurethane bushing must be lubricated occasionally with Synthetic Grease (Super Lube from ebay). If you don't lubricate these bushings, the sway bar may become frozen in its axis, and subsequently may cause bending of the drop links, or even shearing off the mounting point of the drop link on the coilover.

The way to test is to completely disconnect both drop links from sway bar, and then try to swing the bar yourself; it should move freely. When I checked mine it was nearly frozen in place; I lubricated it once and since have switched back to the stock rubber bushing for peace of mind. One other reason that I changed back to rubber bushing is that while the rear bushing is easy to lubricate, the front one is a pain to access. In fact I had to have my tuner Lucent change the front bushing for me. Basically I am busy with work and car is daily driver; I don't want the hassle of having to bring car to a shop to lubricate that front sway bar.

If polyurethane is such a problem, why does GMG use it? It is supposed to be more durable than the rubber counterpart. AND it does make the suspension feel firmer (yes I have switched back and forth to compare) and more planted. Very subtle, but definitely noticeable.

For those new to this topic, remember that after-market suspension components are not maintenance free. This bushing is one good example, but these other links with metallic (heim) joints also have to be inspected for wear and tear - they do wear. The inspection could be every couple of years for street use, and more frequently for track obviously. A little more work but in return, car handles with aggressiveness and that's why people still do it.

For lubricant, I've read different things so not sure, but I believe that while you could use either SYNTHETIC or PETROLEUM based grease for polyurethane bushing, you should use only the synthetic stuff, ie the Super Lube on ebay I quoted above, for the stock rubber bushing.

In picture below, black bar and black rubber bushing are stock, blue bar and red urethane bushing are GMG. The Super Lube Synthetic Grease could be purchased from ebay http://www.ebay.com/itm/SUPER-LUBE-S...-/161003162819.

 

bad ***!!!!

 

Sorry ("bad ***" ) pic above got deleted accidentally:

 

Thought you would be interested in a picture of Bilstein's test driver. LOL. It's only ad material and not sure how much "HE" is involved, but good to know the name is there.