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Discussion Starter #1
Has anyone experienced the 991 GT3 front sway bar in the 981 GTS or S?

What is the best rear toe setting after install? Any alignment recommendations with the new bar?

The GTS stock alignment in awful... I have the sports suspension option and the car won't put full power down quickly coming out of tight turns.

Thanks,
Lou Hudyman
 

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yes,

i have it on our car...i have it in stock...including the front bushings that hard to find in stock..

http://www.schnellautosports.com/specials/gt3-sway-bar-upgrade-kit-for-991-981-997-gt3.html.


and here how it looks, on the 2nd page..

http://www.planet-9.com/981-cayman-boxster-modifications/101439-gts-mod-day.html


and here is how it performed


http://www.planet-9.com/981-cayman-...2696-update-track-video-schnell-upgrades.html

and you can ask lacquer here ... he has it in his car as well..it works..

it significantly reduces front compliant..


thanks
Lemon
 

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While you can retrofit a 997.2 GT3 bar under there, I would not recommend it. I would say that we have done about 3-4 of them so far and I have driven them on the track. the 991 GT3 bar is a hollow bar, not solid and is a 4-hole bar, not 5 hole like bars previously were. However, there is no more powerful tuning tool on a Porsche than the front sway bar. FACT! As for recommended alignments, you can get to almost 2.0 degrees of camber all around with a lowering spring setup and maxing out stock adjustment points. I would stick to at least 1mm of toe per corner; pointed out on the front and in on the back. You can run more if you would like in the rear to increase stability and you can run more toe out in the front than that if you want a more crisp turn-in. Adding some more wont hurt it. The temps actually aren't crazy when you find yourself with too much too. Beware though...my street car has zero toe in the LR and 2mm in the RR which makes it a handful at tracks with long, fast right turns. The larger front bar is what will allow you to lean on the car. If you install it and have too much push or understeer on your softest front setting, follow it up with the x73 rear bar or something from Tarett if you want adjustments. Good luck!
 

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Discussion Starter #4 (Edited)
While you can retrofit a 997.2 GT3 bar under there, I would not recommend it. I would say that we have done about 3-4 of them so far and I have driven them on the track. the 991 GT3 bar is a hollow bar, not solid and is a 4-hole bar, not 5 hole like bars previously were. However, there is no more powerful tuning tool on a Porsche than the front sway bar. FACT! As for recommended alignments, you can get to almost 2.0 degrees of camber all around with a lowering spring setup and maxing out stock adjustment points. I would stick to at least 1mm of toe per corner; pointed out on the front and in on the back. You can run more if you would like in the rear to increase stability and you can run more toe out in the front than that if you want a more crisp turn-in. Adding some more wont hurt it. The temps actually aren't crazy when you find yourself with too much too. Beware though...my street car has zero toe in the LR and 2mm in the RR which makes it a handful at tracks with long, fast right turns. The larger front bar is what will allow you to lean on the car. If you install it and have too much push or understeer on your softest front setting, follow it up with the x73 rear bar or something from Tarett if you want adjustments. Good luck!
Thank you! I am going with the 991 gt3 bar!

Will take out some of my rear toe as I have 10 minutes on each side... Probably too much for putting full power down at the autocross.
image.jpg
 

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How much toe in the rear do you have in mm? I can't read from my iPhone. I have run as much as 10mm per side as an experiment to see temps and tire wear and handling. DO NOT TRY...but...it wasn't egregious but near impossible to pus across the shop floor!!.Is the car "pushy" for you at corner exit? If so, you might want the rear bar but not until you answer the question. You're welcome...any time. I'm always glad to help!
 

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Discussion Starter #6
How much toe in the rear do you have in mm? I can't read from my iPhone. I have run as much as 10mm per side as an experiment to see temps and tire wear and handling. DO NOT TRY...but...it wasn't egregious but near impossible to pus across the shop floor!!.Is the car "pushy" for you at corner exit? If so, you might want the rear bar but not until you answer the question. You're welcome...any time. I'm always glad to help!
The car does not push at all. The car is loose at exit... And it does not put the power down or take a quick set after a tight turn... Constantly waiting on the car to respond.

I just inspected my limited slip differential after just 3,500 miles and it is totally shot... Completely gone! Crappy Porsche LSD/PTV did not even last two track days and two autocrosses... I have had several Guard LSD's and an OS Giken and both of those products were indestructible... Can't believe the poor quality option (PTV) that Porsche is putting in these new cars. I will have the dealer replace the LSD under warranty.
 

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The car does not push at all. The car is loose at exit... And it does not put the power down or take a quick set after a tight turn... Constantly waiting on the car to respond.

I just inspected my limited slip differential after just 3,500 miles and it is totally shot... Completely gone! Crappy Porsche LSD/PTV did not even last two track days and two autocrosses... I have had several Guard LSD's and an OS Giken and both of those products were indestructible... Can't believe the poor quality option (PTV) that Porsche is putting in these new cars. I will have the dealer replace the LSD under warranty.
I'm just curious how did you inspect it? What were the symptoms of it failing? Thanks carl
 

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For any of you that are curious, the easiest way to check it is to jack up one side of the car and find how many lb/ft of force it takes to slip the unloaded tire; using a torque wrench on the axle nut (32mm maybe?) apply force til it moves. Most motorsport units like the Guard are set to 50ish lb/ft. Ive heard stories of them not being warrantied. Good luck!

And a bigger front sway bar would calm that terrible power down at exit but if your LSD is shot, start there first!


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Discussion Starter #10
I'm just curious how did you inspect it? What were the symptoms of it failing? Thanks carl
Carl, with the car on a lift just spin the left rear wheel back and forth - if the right rear stays stationary the diff is gone. Cheers, Lou
 

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Carl, with the car on a lift just spin the left rear wheel back and forth - if the right rear stays stationary the diff is gone. Cheers, Lou
Hi Lou,
Sorry to hear about your problem. I'm wondering, like Carl, can you be more specific on what you experienced with the LSD fail? Is it just that the rear of the car gets really loose on exit of a tight turn? Did it make any noise to warn?
Thanks in advance.
 

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Discussion Starter #12
Lacquer, the symptoms were not obvious. I went to my first autocross and the car was somewhat loose, but I could squeeze the gas coming out of turns and put full power down... Then, two weeks later on the same lot I just could not get the rear to hook up under full power... The car was looser coming out of the corners... I thought it was the tires (crappy P-Zeros), but after putting the car on the lift I could spin the left rear tire back and forth (no movement on the right rear). Sad that Porsche sells these expensive cars with terrible components. I have received several messages from members who had the same experience with Cayman, Boxster and GT3. Only real long term solution is aftermarket diff from Guard or Giken...
 

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Some interesting insights in this thread.

My BS with X73 and PTV has nice turn in and feels really "pointy" on street driving. On the track however, I have had to feed power very slowly coming out of tight corners, otherwise the rear would break loose. That equates to a lot of lost time, especially on corners entering into straights.

I've always thought that this behavior was characteristic of a mid-engine car, but am now wondering if a thicker front sway bar could improve the situation (while not causing the car to push)...

Does anyone have any data on how the stiff the GT3 front sway bar is (over its range of adjustments) vs. to the X73 front, or the various other OEM fronts?
 

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Discussion Starter #14
I won't have real data on the new bar (vs OE) until April Limerock and autocross events. Maybe someone in FL or CA has experience.

My hypothesis is that PTV will benefit from a bigger front bar and put less tax on the LSD coming out of corners.
 

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Lou, this is from another post i did.
I saw a post that a member with a CGTS thought their LSD
/PTV was bad. The method he used was with the car in the air turning one wheel. If the other wheel didn't rotate the OP said that the LSD was bad. To test the theory I tried it on my car . My car that also has PTV/LSD and only one wheel turns, the other side does not move . My car is new 600miles no track and works perfectly so i question using the method to diagnose a bad LSD. carl https://www.youtube.com/watch?v=sFTN...ature=youtu.be
 

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Discussion Starter #16
Lou, this is from another post i did.
I saw a post that a member with a CGTS thought their LSD
/PTV was bad. The method he used was with the car in the air turning one wheel. If the other wheel didn't rotate the OP said that the LSD was bad. To test the theory I tried it on my car . My car that also has PTV/LSD and only one wheel turns, the other side does not move . My car is new 600miles no track and works perfectly so i question using the method to diagnose a bad LSD. carl https://www.youtube.com/watch?v=sFTN...ature=youtu.be
Carl, thanks for the info & insight! Perhaps my mechanic is unfamiliar with PTV diagnosis. If we could get a certified Porsche technician opinion that would be helpful...
 

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Discussion Starter #17
Lou, this is from another post i did.
I saw a post that a member with a CGTS thought their LSD
/PTV was bad. The method he used was with the car in the air turning one wheel. If the other wheel didn't rotate the OP said that the LSD was bad. To test the theory I tried it on my car . My car that also has PTV/LSD and only one wheel turns, the other side does not move . My car is new 600miles no track and works perfectly so i question using the method to diagnose a bad LSD. carl https://www.youtube.com/watch?v=sFTN...ature=youtu.be
OK, so bad news from Porsche on diagnosing anD fixing PTV LSD issues/problems:

1) You can't check PTV-LSD operation by spinning the wheels while the car is off the ground like a normal mechanical LSD as PTV is controlled electronically. 2) And even worse, there are NO service procedures or parts available for the PTV/LSD as of yet! Even the Porsche dealer can't fix it if they go bad.

This information came straight from a Porsche Master Technician.
 

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Carl, thanks for the info & insight! Perhaps my mechanic is unfamiliar with PTV diagnosis. If we could get a certified Porsche technician opinion that would be helpful...
The methodology I described above is used by race teams all over the world. It's just math and force. Re-read. It will make sense. if you have questions, ask them. But what you seek is right there.
 
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