strut tower failure
02-28-2019, 12:55 PM
#721
Rennlist Member
Starting to get serious when shops are noticing and talking about this. I wonder how long Porsche has been aware of this problem with 981 and 991. They’ve been making them for 6+ years now.
02-28-2019, 01:55 PM
#722
Racer
I believe these strut towers are cast based on the geometry and the markings, some have suggested "thinning" of the metal due to the forming (forging) process, I can assure you these are not forged.
Looking at the base of the tower, the purpose of the integrated gussets is to distribute the stress over a larger area, based on what we have seen it would appear that the gusset design is inadequate.
My suggestion to Porsche would be to modify the gusset design and increase the radius of the bend where the tower transitions from horizontal to vertical plane, both of these changes could be very effective in improving the distribution of stresses.
Having said that, for the current crop of affected owners, I have to believe that someone will develop a simple external reinforcement plate to improve the distribution of stresses by transferring the loads away from the bend/tangent area where the failures appear to occur/originate. The plate would be mounted atop the strut tower and would extend down the vertical walls of the tower approximately 50-75mm, the plate would be mounted to the top of the tower using the existing strut assembly hardware and would be glued and riveted to the horizontal wall of the tower.
Looking at the base of the tower, the purpose of the integrated gussets is to distribute the stress over a larger area, based on what we have seen it would appear that the gusset design is inadequate.
My suggestion to Porsche would be to modify the gusset design and increase the radius of the bend where the tower transitions from horizontal to vertical plane, both of these changes could be very effective in improving the distribution of stresses.
Having said that, for the current crop of affected owners, I have to believe that someone will develop a simple external reinforcement plate to improve the distribution of stresses by transferring the loads away from the bend/tangent area where the failures appear to occur/originate. The plate would be mounted atop the strut tower and would extend down the vertical walls of the tower approximately 50-75mm, the plate would be mounted to the top of the tower using the existing strut assembly hardware and would be glued and riveted to the horizontal wall of the tower.
02-28-2019, 02:01 PM
#723
Rennlist Member
There was an update yesterday on youtube's "vehicle villains" channel for that yellow GT4 that had the strut tower fail. ....I had a little laugh when the owner wiped off a big deposit from a flying bird off the fender, smeared it onto the tire, then put his hand right into his pocket, then continued to drink his coffee with that hand and the lid off the cup.
On a separate note, took off all the plastic trim around the frunk yesterday to adjust the driver side bumper alignment to the fender by the headlight area (my ocd'ness). Took the opportunity to inspect the strut towers carefully per the video. It took less than 5 mins to pull off the trim.. Well worth it for the piece of mind to ensure you don't have any signs damage.
02-28-2019, 02:09 PM
#724
I believe these strut towers are cast based on the geometry and the markings, some have suggested "thinning" of the metal due to the forming (forging) process, I can assure you these are not forged.
Looking at the base of the tower, the purpose of the integrated gussets is to distribute the stress over a larger area, based on what we have seen it would appear that the gusset design is inadequate.
My suggestion to Porsche would be to modify the gusset design and increase the radius of the bend where the tower transitions from horizontal to vertical plane, both of these changes could be very effective in improving the distribution of stresses.
Having said that, for the current crop of affected owners, I have to believe that someone will develop a simple external reinforcement plate that would extend down the vertical walls of the tower approximately 50-75mm, this plate could be glued and riveted to the horizontal wall of the existing tower (In addition to being secured at the top by the strut assy. bolts) and would greatly improve the distribution of stresses by transferring the loads away from the bend/tangent area where the failures appear to occur/originate.
Smells like a business opportunity...
Looking at the base of the tower, the purpose of the integrated gussets is to distribute the stress over a larger area, based on what we have seen it would appear that the gusset design is inadequate.
My suggestion to Porsche would be to modify the gusset design and increase the radius of the bend where the tower transitions from horizontal to vertical plane, both of these changes could be very effective in improving the distribution of stresses.
Having said that, for the current crop of affected owners, I have to believe that someone will develop a simple external reinforcement plate that would extend down the vertical walls of the tower approximately 50-75mm, this plate could be glued and riveted to the horizontal wall of the existing tower (In addition to being secured at the top by the strut assy. bolts) and would greatly improve the distribution of stresses by transferring the loads away from the bend/tangent area where the failures appear to occur/originate.
Smells like a business opportunity...
Personally I just hope for the best and that it won't happen to me. Avoid potholes and going off track where I could hit a big bump at all cost. And if it happens then I will make the insurance or Porsche pay for it. No need to have sleepless nights over it. This shouldn't happen, but because they push the envelope making things as light as possible, $hit does happen. GT4 and GT3 are still amazing cars regardless.
02-28-2019, 02:43 PM
#725
There was an update yesterday on youtube's "vehicle villains" channel for that yellow GT4 that had the strut tower fail. The link is easy to find. It was hard to understand the Scottish mechanic through his thick burr but I think he was saying that the first crack started with one of the vertical bolts on the right side of the tower if facing the windshield. The owner said Porsche told him it wasn't covered due to some sort of external forces verbiage. Interestingly, his repair quote was on the order of 5 or 6k pounds. They discussed removing the fender for the repair, plus some of the panels, and pointed out the glue that Porsche uses to secure the strut tower. None of them mentioned using a jig for the frame straightening so who knows. I had a little laugh when the owner wiped off a big deposit from a flying bird off the fender, smeared it onto the tire, then put his hand right into his pocket, then continued to drink his coffee with that hand and the lid off the cup.
02-28-2019, 02:56 PM
#726
Racer
Mounting the plate on the top of the strut tower (The outside) would not impact the overall suspension setup.
02-28-2019, 03:42 PM
#727
Not ascetics, just strength wise. The pressure is coming from the inside.. Mounting something on the outside would to little to nothing, unless it was glued/riveted
02-28-2019, 04:12 PM
#728
Three Wheelin'
02-28-2019, 04:44 PM
#729
Racer
The load is applied to the underside of the tower, anything that takes the load applied to the underside of the tower and distributes it elsewhere (IE: To the vertical plane of the tower) should contribute to a reduction in strut tower failure.
I agree that mounting something on the outside without glue/rivets would be futile, as would mounting anything on the inside without glue/rivets.
It would be very challenging to develop and manufacture a "contoured insert" that would mount inside the strut tower as a interference fit connection. The tolerance that you would need to maintain to effectively distribute the load away from the horizontal plane to the vertical plane would be virtually unachievable due to standard deviation in the manufacturing process of the vehicle/chassis. Assuming you could develop such a clever insert you would then need to resolve other issues such the differential coefficient of thermal expansion between the insert and the chassis under the wide variety of conditions one expects to encounter with a vehicle driven in varying climates and operating conditions.
I agree that mounting something on the outside without glue/rivets would be futile, as would mounting anything on the inside without glue/rivets.
It would be very challenging to develop and manufacture a "contoured insert" that would mount inside the strut tower as a interference fit connection. The tolerance that you would need to maintain to effectively distribute the load away from the horizontal plane to the vertical plane would be virtually unachievable due to standard deviation in the manufacturing process of the vehicle/chassis. Assuming you could develop such a clever insert you would then need to resolve other issues such the differential coefficient of thermal expansion between the insert and the chassis under the wide variety of conditions one expects to encounter with a vehicle driven in varying climates and operating conditions.
02-28-2019, 04:52 PM
#730
Drifting
^ redirecting the forces such that they are focused elsewhere other than the strut tower is likely too challenging, which is why I feel, as a non-engineer or even a person who knows anything about this, that changing the characteristics of the force is probably the better route - ie, lengthen the duration of it so the same impact is dispersed over a longer period = lower power on the tower.
02-28-2019, 04:54 PM
#731
02-28-2019, 05:15 PM
#732
03-01-2019, 10:08 AM
#734
Rennlist Member
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According to this website, yes.
https://nemigaparts.com/cat_spares/pet/porsche/
Left part is 991.501.477.00
Right part is 991.501.478.00
https://nemigaparts.com/cat_spares/pet/porsche/
Left part is 991.501.477.00
Right part is 991.501.478.00
03-01-2019, 11:45 AM
#735
According to this website, yes.
https://nemigaparts.com/cat_spares/pet/porsche/
Left part is 991.501.477.00
Right part is 991.501.478.00
https://nemigaparts.com/cat_spares/pet/porsche/
Left part is 991.501.477.00
Right part is 991.501.478.00