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Rear sway bar upgrade?

Old 07-14-2018, 04:17 AM
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RobC4sX51
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Default Rear sway bar upgrade?

i believe the stock 987.1 rear sway bar is 19mm. Is a 22mm enough of an upgrade to justify time & $ for track use? Looking for a bit more rearend grip and flatter body roll. Anyone done something they care to share? TIA.
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Old 07-14-2018, 04:15 PM
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certz
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I believe you are thinking about this backwards. You would be better off going with a larger front sway bar to balance the car overall. In SPC, most of us run the Tarett 19.1mm hollow bar. Even though it is basically the same diameter as the stock, it has a higher spring rate. We balance that with the 28.6mm GT front sway bar. All that said, we all run the bars full stiff front (or half a hole from full) and full soft rear bar. Some of the guys run the stock rear bar because they want it even softer. Of course, you also have to take into account what suspension you have, ride height and tires, but, in general, I think you should be looking at the front of the car not the rear for balance based on what you have said.
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Old 07-15-2018, 02:22 PM
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Bill Lehman
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A stock 987 understeers. Stiffening the rear bar will help this and make the car more neutral. The rear bar is easy to install. That said, stiffening both ends will help the car. I used the adjustable GT3 front bar and Tarett adjustable rear bar which allows fine tuning to your style.
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Old 07-15-2018, 08:02 PM
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Brian C in Az
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Originally Posted by RobC4sX51 View Post
Looking for a bit more rearend grip and flatter body roll. Anyone done something they care to share? TIA.
An Anti sway bar REDUCES grip, it does not increase grip. More rear bar makes the rear more loose. More front bar makes the front more loose. Anti sway bars are a compromise item, they give a little, but at a cost of something else. In a perfect design, you would not have either front or rear anti sway bars. The larger the bar, the less independent the wheels become. More bar reduces independent movement at the wheels. You want more rear grip? Try removing the rear bar for a day. I did. You will be surprised at the results. (Not surprised like "Oh S*@^%, the rear end is out of control.) You might find that you prefer the car with no rear bar. BTW, Front and rear factory bars are designed to make the car understeer. The lawyers want the car to crash front first since that is where all the crash safety bits are located.
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Old 07-18-2018, 11:49 PM
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RobC4sX51
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All interesting (and contradicting) replies! My first step is now to try 285mm rear tires (from 275). I have way more experience with a 911 on the track. I have only been in a spin on the track in my 987! But stay tuned. Thx guys.
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Old 07-19-2018, 03:32 PM
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certz
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This may help - it is a good cheat sheet.
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Old 07-19-2018, 04:48 PM
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^^^^^^^ I keep that in my setup book... As much as I think I have it memorized, I still go back to that cheat sheet..

Great advice!
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Old 08-05-2018, 12:03 PM
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RobC4sX51
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Originally Posted by Bill Lehman View Post
A stock 987 understeers. Stiffening the rear bar will help this and make the car more neutral. The rear bar is easy to install. That said, stiffening both ends will help the car. I used the adjustable GT3 front bar and Tarett adjustable rear bar which allows fine tuning to your style.
Bill, I installed the Tarett Eng adjustable 22mm rear bar and noticed a significant improvement in the understeer and a flatter body roll. I do have the R suspension (struts & springs) too. I’m still on Conti Ext Con 235 & 275 tires but I’m going to try them in 245 & 285 later in the month. Just got back from NCM & the car with new Giro Disc rotors was awesome! Really like driving this car on the track.
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