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GT4 RS Strut tower failure...

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Old 07-17-2024 | 05:27 PM
  #46  
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Originally Posted by RRRacing
Works on any variant with GT3/4 inverted struts that utilize the solid OEM GT camber plates, so that should include the 718 GTS 4.0

The root cause of this issue is the fact that there is zero elastic deflection or deformation of the stock camber plates upon impact…. So you can reinforce the shock towers all you want, it may help a little bit but mostly it will just transfer the failure point from one location to the other.

Rafi
As far as I know the GTS uses a standard top hat, like this.


In the case of Tarett mounts, the race style fits coilovers and the clubsport is for standard PASM struts like GTS.

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lowbee (07-18-2024)
Old 07-17-2024 | 05:40 PM
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Originally Posted by Josh_357
As far as I know the GTS uses a standard top hat, like this.


In the case of Tarett mounts, the race style fits coilovers and the clubsport is for standard PASM struts like GTS.


If your top mount looks like the one in the pic, then your car is not affected. The standard non-GT PASM suspension has more travel larger bump stops, and that upper plate will actually deform when hit really hard. Failures on this setup is very rare.

Rafi


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Old 07-17-2024 | 05:54 PM
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Originally Posted by RRRacing
Works on any variant with GT3/4 inverted struts that utilize the solid OEM GT camber plates, so that should include the 718 GTS 4.0

The root cause of this issue is the fact that there is zero elastic deflection or deformation of the stock camber plates upon impact…. So you can reinforce the shock towers all you want, it may help a little bit but mostly it will just transfer the failure point from one location to the other.

Rafi
Do Porsche motorsport camber plates have the same problem ?
Old 07-17-2024 | 06:11 PM
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Originally Posted by 7184RS
Do Porsche motorsport camber plates have the same problem ?
I have heard that the track cars have had this issue, but I don’t think the race teams are out there posting these things on social media 😂 also repairing a non-registered car is much less consequential since when you go to sell it nobody is going to go looking up the carfax.

That said, there are many differences in the suspension design with the motorsport struts vs GT3/GT4, like much stiffer springs, smaller wheels with higher profile tires, and potentially stiffer bump stops which might help a lot.

Rafi


Last edited by RRRacing; 07-17-2024 at 06:12 PM.
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Old 07-18-2024 | 11:43 AM
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...

Last edited by enduro; 07-18-2024 at 11:45 AM.
Old 07-18-2024 | 11:57 AM
  #51  
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Originally Posted by RRRacing
I have heard that the track cars have had this issue, but I don’t think the race teams are out there posting these things on social media 😂 also repairing a non-registered car is much less consequential since when you go to sell it nobody is going to go looking up the carfax.

That said, there are many differences in the suspension design with the motorsport struts vs GT3/GT4, like much stiffer springs, smaller wheels with higher profile tires, and potentially stiffer bump stops which might help a lot.

Rafi
I meant using motorsport camber plates on a regular GT4 RS given that you mentioned that the main culprit is the OEM camber plate
Old 07-19-2024 | 02:42 PM
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Originally Posted by 7184RS
I meant using motorsport camber plates on a regular GT4 RS given that you mentioned that the main culprit is the OEM camber plate
I don’t see anything about the design of the Motorsport or any aftermarket camber plate that would result in them failing sooner than the OEM GT3 plates.

To protect the delicate strut towers, you would have to build into the camber plate some form of dampening. Now, it would be counterproductive to install a rubber or poly upper mount because the obvious design intent of the GT cars is to have a solid pillow ball strut interface with the strut tower.

In the case that you wanted to properly design an aftermarket suspension for these applications, then you would shorten the shock body compared to the OEM GT shocks, thereby increasing the stroke of the shock and then in addition to the stock open cell foam bump stop you would add a hard poly or hard rubber bump to absorb the large impacts that occur when the suspension completely bottoms out.

Rafi

Old 07-19-2024 | 02:52 PM
  #53  
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Originally Posted by RRRacing
I don’t see anything about the design of the Motorsport or any aftermarket camber plate that would result in them failing sooner than the OEM GT3 plates.

To protect the delicate strut towers, you would have to build into the camber plate some form of dampening. Now, it would be counterproductive to install a rubber or poly upper mount because the obvious design intent of the GT cars is to have a solid pillow ball strut interface with the strut tower.

In the case that you wanted to properly design an aftermarket suspension for these applications, then you would shorten the shock body compared to the OEM GT shocks, thereby increasing the stroke of the shock and then in addition to the stock open cell foam bump stop you would add a hard poly or hard rubber bump to absorb the large impacts that occur when the suspension completely bottoms out.

Rafi
I always thought about a "lowering" camber plate, so that the shock would ride higher in the stroke for the same vehicle ride height. In otherwords, a camber plate that lowers the car 10mm and then you adjust the collars to get back that 10mm ride height, you would loose some droop. Thoughts on that approach, did you consider this or any other approach when solving the problem?
Old 07-19-2024 | 08:11 PM
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Originally Posted by Josh_357
I always thought about a "lowering" camber plate, so that the shock would ride higher in the stroke for the same vehicle ride height. In otherwords, a camber plate that lowers the car 10mm and then you adjust the collars to get back that 10mm ride height, you would loose some droop. Thoughts on that approach, did you consider this or any other approach when solving the problem?

Yes definitely thought about that, you could theoretically design a new camber plate with less stack height, then that would effectively increase the travel but the downsides to consider are

(1) is the shock designed for this amount of droop? This is something important to consider because it’s an inverted shock, and this design is most effective/reliable at a certain minimum insertion… less insertion means more lateral stress & less lateral stiffness.

(2) even if you did this, you would still have to remove the struts and take them apart to install a bump poly bushing, but because the inverted design, stiff poly bushings don’t work well inside an enclosed inverted strut because they do not compress when dimensionally confined to the inside of the strut.

(3) Our solution is so much more simple, elegant, easy to install, and very easy to “reset” in case of a breakaway event.





-Rafi

Last edited by RRRacing; 07-19-2024 at 08:15 PM.
Old 07-19-2024 | 08:39 PM
  #55  
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Originally Posted by RRRacing
Yes definitely thought about that, you could theoretically design a new camber plate with less stack height, then that would effectively increase the travel but the downsides to consider are

(1) is the shock designed for this amount of droop? This is something important to consider because it’s an inverted shock, and this design is most effective/reliable at a certain minimum insertion… less insertion means more lateral stress & less lateral stiffness.

(2) even if you did this, you would still have to remove the struts and take them apart to install a bump poly bushing, but because the inverted design, stiff poly bushings don’t work well inside an enclosed inverted strut because they do not compress when dimensionally confined to the inside of the strut.

(3) Our solution is so much more simple, elegant, easy to install, and very easy to “reset” in case of a breakaway event.





-Rafi
Thanks Rafi, appreciate you adding some input. Definitely considering your solution in the off season.



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