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Yoshi, thats because the strut tower is stamped steel not cast aluminum. The plate adds thickness to the tower to keep it from deforming.
Buy the way i was going to call you and see how MY first GT4 is holding up. No issues i hope..carl
Installed the SP brackets and spacers today, not a bad install, some comments below. I went with 26lbs on the strut bolts, still not sure that's tight enough, would love for someone to correct me right or wrong.
A few things to note on the passenger side:
-The spacer bolt/washer combo is a little short (or seems it at first) so make sure you push down on the top of the bolt to give yourself another 1/2 a thread it will just be enough to get the lock nut on the bottom threaded and on there.
-Cutting the cabin filter is really just a thin splice, easy to line up and since the part you cut is rubber your knife should go right through and it won't even look like it's cut
A few things to note on the driver side:
-The photos from SP indicate that they cut the the washer fluid plastic cover in a semi-circle. I tried another route and actually drilled through the piece that secures the filler to the chassis since it's plastic. Then I zip tied it through the hole and around the bolt from the strut tower brackets. See photo below, I left the tag end long on the black zip tie for visual.
If you finagle it right when the large idiotic plastic cowl is back on your fluid filler should be close to where it was before and operational. Takes some messing around to get it usable, but I'd rather have it this way than cut into hard plastic and still have it be flopping around under there.
really what they should have is a stamped steel insert inside the strut tower with a flange at the bottom around the circumference. that way all the stress of impact would be transferred to the body not the cast aluminum tower . carl
+1
Agreed. The ones I've seen have all torn away below this reinforcement plate. I would love it if it works and for $350 it would provide piece of mind but I just don't see how this would prevent the problem. Am I missing something?
Agreed. The ones I've seen have all torn away below this reinforcement plate. I would love it if it works and for $350 it would provide piece of mind but I just don't see how this would prevent the problem. Am I missing something?
I have little doubt that Mike Levitas over at TPC Racing could come up with something for this if he feels something can be done. He understands suspension quite well. Would be interesting to get his take. Hayden over at WEVO would be another. Or Craig at SmartRacing. There are others still...
But I don't know if I would apply a factory piece without the rest of the system it was designed to work with. And it sounds like the race cars do this, too. Just my outside observation, but I do think the real issue here could be that the strut top's interface with the cast tower is applying too much force in a limited footprint. A thin (?) steel insert might just help here. Wouldn't add a lot of weight, and the ride height could easily be adjusted to account for the slightly thicker strut tower.
Why wouldn't this be happening to the GT3 since it uses the same front suspension?
That was discussed a while back in this thread. Maybe, maybe not. GT4 has its engine in a different place, and a very different unibody from the seats back—essentially halving the "void" for the interior of a GT3. Different frequencies, stiffnesses, etc.
What we haven't seen, which I was worried about back then, was a lot of these failures. Seems like a pretty limited number given how many GT4s are out there.
I won't claim benefit or no benefit, however, many cars have a piece of steel that sits on top of the strut tower and under the nuts. There is no support or bracing attached to this piece. There must be a reason for it. For example:
Majority of the front engine Japanese cars have a reinforcement plate on the strut tower to support the engine weight and flex on the front end.
There is a reason why the CS have those plates and since there isn't any weight on Porsches, the OEM's didn't need to reinforce the front strut tower.
Agreed. The ones I've seen have all torn away below this reinforcement plate. I would love it if it works and for $350 it would provide piece of mind but I just don't see how this would prevent the problem. Am I missing something?
+1 ... The plate placed on top does nothing but give you a fake warm and fuzzy feeling.
Fwiw, my sense from the beginning of this thread was that an "upside down cup-like" steel insert on the underside of the strut tower to spread the load across the aluminum casting might go a long way to addressing the failure we've seen photos of. Wouldn't be that hard to engineer or manufacture for someone like WEVO or TPC, and would probably add real peace of mind. Wouldn't cost that much, and the suspension could be adjusted to account for the tiny ride height change.
That said, we haven't seen anywhere that many failures as time has gone on.
"upside down cup-like" for sure. One of those solid (no swivels) strut bars can also remove some of the stress off of the towers. Along with not running the front sways too soft (some of the tension will fall into the sway bar mounting points and not top of the towers). But all this is academic.
I find it fairly concerning that the (unofficial) analysis showed no casting flaws. Also concerning that there was a pre-existing stress crack that was caused from normal operation (no reported bumps, etc.).
Further concerning that no other components (besides bent wheel) failed first.
Could other components have unseen internal stress fractures? Perhaps a subframe, control arm, or shock tower?
It seems the component is underdesigned.
Perhaps it has been litigated out (i.e. "don't breathe wrong on your car"), but one would think the OEM would apply a factor of safety that encompasses (of course limited to a certain extent) end use, user modification, user error and production error.
Have cost cutting measures lowered these safety factors?
Porsche no doubt put hundreds of thousands of test miles on several pre-production GT4s. Test miles that of course included banging curbs at the 'Ring and Weissach circuits. Did this issue never come up?
The fact it is braced on the Clubsport makes one believe they know it is a weak point.
What is the extent to which corrosion could further weaken the area? The component is obviously insulated form galvanic corrosion but these sealers and coatings can wear over time, allowing corrosion from dissimilar metals. These worn coatings, as well as clogged drains, and others can lead to corrosion.
I have little doubt that Mike Levitas over at TPC Racing could come up with something for this if he feels something can be done. He understands suspension quite well. Would be interesting to get his take. Hayden over at WEVO would be another. Or Craig at SmartRacing. There are others still...
But I don't know if I would apply a factory piece without the rest of the system it was designed to work with. And it sounds like the race cars do this, too. Just my outside observation, but I do think the real issue here could be that the strut top's interface with the cast tower is applying too much force in a limited footprint. A thin (?) steel insert might just help here. Wouldn't add a lot of weight, and the ride height could easily be adjusted to account for the slightly thicker strut tower.
Would love to see someone at TPC or WEVO come up with a steel insert to remedy this.
Has anyone brought this to their attention?
Would be interesting to see what they say first. Just named two I have a lot of respect for when it comes to suspension components. Another would be Chuck at Elephant Racing. There are others, as well...
I'm ready to buy a couple of parts as an insurance policy. ($300-$500)/($25000 repair) is a pretty small percentage. Not to mention the time it takes to get the repair job done.
Fwiw, my sense from the beginning of this thread was that an "upside down cup-like" steel insert on the underside of the strut tower to spread the load across the aluminum casting might go a long way to addressing the failure we've seen photos of. Wouldn't be that hard to engineer or manufacture for someone like WEVO or TPC, and would probably add real peace of mind. Wouldn't cost that much, and the suspension could be adjusted to account for the tiny ride height change.
That said, we haven't seen anywhere that many failures as time has gone on.
It's great that there's not been many failures, however it could be catastrophic & also is a super expensive fix.
I've read this entire thread & been following. Agree with Karl & others that placing steel brackets on top of tower would add minimal reinforcement. Underneath the strut will move fore/aft & continue to stress aluminum tower top of bracket, & eventually, after enough metal fatigue will fail.
Thinking about a more robust intervention, I agree with Stout in that a steel bracket should be placed on the underside of the tower. The strut tower top can be substantially fortified, by placing a larger diameter forged steel base shim on the underside of tower & also bolting the P motorsport steel brackets on the top. Simply think of it (strut tower top), being an aluminum sandwich with steel as the bread. High impacts to the shock/strut would cause the mount to directly stress steel, & indirectly aluminum (over larger surface area), further supported by steel frame top. Could run over a tank mine before it busts.
Will discuss this idea with engineer & machinist friends, to get their input.
11-04-2017, 09:50 PM
