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Old February 4th, 2010, 07:15 PM   #21
Docdanracy
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high speed handling and low speed handling are two completely different animals.
In low speed cornering Boxsters (and 996s, 997s) tend to push (understeer) at lower speeds. As speeds increase this is mitigated somewhat but not completely.
I do not know what exactly Pedro's brace is supposed to do or how it attaches to the car so I can't comment on it's affect on your situation.
Also without knowing what your alignment specs are, I don't know why your car would get tail happy...while cornering unless you are experiencing drop throttle oversteer or upsetting the balance of the car mid corner by applying brakes or throttle.
You may have some toe out causing this.
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Old February 4th, 2010, 08:39 PM   #22
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Originally Posted by Docdanracy View Post
high speed handling and low speed handling are two completely different animals.
In low speed cornering Boxsters (and 996s, 997s) tend to push (understeer) at lower speeds. As speeds increase this is mitigated somewhat but not completely.
I do not know what exactly Pedro's brace is supposed to do or how it attaches to the car so I can't comment on it's affect on your situation.
Also without knowing what your alignment specs are, I don't know why your car would get tail happy...while cornering unless you are experiencing drop throttle oversteer or upsetting the balance of the car mid corner by applying brakes or throttle.
You may have some toe out causing this.
Here's a link Doc http://www.pedrosgarage.com/Site_2/TechnoBrace.html
I get off the brakes after the break point and accelerate through the turn and out and it did just recently start occurring. I'll get my alignment specs tomorrow when I go to Tillman's to discuss getting my car ready for the season. I'll also talk to them about sponsorship so did the date for the AX you were looking for sponsorship get finalized?
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Old February 4th, 2010, 09:01 PM   #23
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yes, it will be the June GGR AX dates..the 12th and 13th. Thanks
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Old February 4th, 2010, 09:17 PM   #24
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I do not know what exactly Pedro's brace is supposed to do or how it attaches to the car so I can't comment on it's affect on your situation.
Pedro's brace is also known as a "lower stress bar":
the lower stress bar was designed to jack the subframes apart and hold them that way during driving. the result is that camber is maintained during hard cornering. most people think that addition of an upper strut tower brace on this car is helpful. the problem at the rear is not the top of the strut towers, it's the bottom of the subframe. when you turn, the outside control arm is pushed toward the center of the car. this causes chassis flex and camber loss

http://986forum.com/forums/showthread.php?t=10817
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Old February 4th, 2010, 09:25 PM   #25
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so it is basically a bottom strut tower brace

The rice rocket crowd has been doing similar stuff on their hotrods for years on the cars with independent rear suspension.
I have a nice Custom (only two in existence) front strut tower brace on my C2.
Now have a larger billet aluminum hex bar installed...it came with both...
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Old February 5th, 2010, 06:33 AM   #26
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Pedro's brace is also known as a "lower stress bar":
the lower stress bar was designed to jack the subframes apart and hold them that way during driving. the result is that camber is maintained during hard cornering. most people think that addition of an upper strut tower brace on this car is helpful. the problem at the rear is not the top of the strut towers, it's the bottom of the subframe. when you turn, the outside control arm is pushed toward the center of the car. this causes chassis flex and camber loss

http://986forum.com/forums/showthread.php?t=10817
So this would not have any effect on over or under steer it just helps keep the tire surface flat on the track? I did a coin check on the tires yesterday and the fronts pass the Lincoln Memorial penny test but the rears just pass the quarter test so maybe I'm just losing traction from the rear tires.
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Old February 5th, 2010, 08:21 AM   #27
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that would be my guess, either low rear tire tread, low rear tire pressures, or a rear alignment issue. the first two are easy to check
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Old February 5th, 2010, 11:52 AM   #28
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Doc sent you a pm reg. AX sponsorship.
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Old February 5th, 2010, 12:04 PM   #29
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Originally Posted by Docdanracy View Post
that would be my guess, either low rear tire tread, low rear tire pressures, or a rear alignment issue. the first two are easy to check
I second that. My back end was stepping out at the start of my last track day and I couldn't figure out why. Going over the car with another driver I checked the tire pressures with his gauge and they were a LOT lower than they should have been. Turns out my gauge was broken. Until that day I didn't fully realize how much tire pressure could change the way a car handles!!!
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Old February 8th, 2010, 08:00 PM   #30
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Thanks for the tire pressure suggestion. I got a Porsche tire gauge and checked my pressures and the rears where both 6 lbs. low. Haven't tried it on the track yet but the ride is certainly much better.
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