hf1

How so?

Former BMW

No sure how best to convince you. Heaviest impact the car took was running over the berms full tilt coming into the bus stop at SMMR. One thing's for sure, I can't vouch for anything the car's previous owner did.

BTW - Porsche denied warranty coverage saying it was not a manufacturing defect!

Five12Free

That’s what I’m suspicious of, the previous owner’s activity.

GoKart Mozart

I have a theory why the right side fails a lot more than the left. Obviously both sides are too weak, as both have failed, and it is common knowledge that any given component is only as strong as it's weakest point, which based on studying some of the pictures of these failures seems to be on the upper cylinder portion of the strut tower. If you compare the left to the right side, you will notice that the left side (the one that fails a lot less) has a boss modeled in to it, where the horn bracket mounts to. While that was probably just some afterthought, it seems to add a little extra material in a critical area. However, it's not enough to prevent the failures, as it just transfers the stress to the next weakest spot, but it does seem to add enough to make a difference, as the ratio of failures is many times more on the other side.

Notice the added mounting boss where the arrow is on the left front strut tower:




[/QUOTE]

That is the only way to go. The strut towers need to be replaced. Welding them is a no no. Which will not hold up.



I think I might have a solution on how to prevent the damage from happening. It's just an idea right now and I need to do some brainstorming and work with someone that is a fabricator. Although I have a machine shop and can machine some of the parts that will be required, I can't do all of it. I don't want to let the cat out of the bag, but I think it would make the strut towers A LOT stronger and would be a better solution than just the plates that are currently available.

Diablo Dude

jmartpr

My friend...if you do come up with a solution you are going to make a lot of us that track the car a lot less nervous. I bet you you will sell all of the kits that you can make.....keep us posted

trkshoe

You have our support (as consumers)...

G-forceGT4

That is the only way to go. The strut towers need to be replaced. Welding them is a no no. Which will not hold up.



I think I might have a solution on how to prevent the damage from happening. It's just an idea right now and I need to do some brainstorming and work with someone that is a fabricator. Although I have a machine shop and can machine some of the parts that will be required, I can't do all of it. I don't want to let the cat out of the bag, but I think it would make the strut towers A LOT stronger and would be a better solution than just the plates that are currently available.[/QUOTE]

That is a good observation Go Kart. If you go back through the thread a few pages & notice my post, which strangely enough didn't get commented on. Probably b/c a post strayed the theme off topic which often happens.
I created my own fix for this inherent weakness in the strut tower by welding extra flanges onto the Porsche motorsport plates, & now have essentially a steel top strut tower which fastened on by M8 bolts to lower or "hidden" chassis bolt holes, such that the strut is reinforced on the car by 6 bolts rather than 3. I'll go back get the link to the pictures I posted. I didn't have to utilize the horn bolt mount, however could of I suppose. I just used the lower bolt holes available b/c on all of the fractures/failures shown, NONE have split down to those bolt holes on the side of the tower. If I get time tomorrow, I'll draw some coloured lines to the holes to use on each side. I had an engineer inspect the FIX I did, & he said it's very reinforced with the modified steel brackets.

Here's the previous post on the fix. I'll have to post some updated photos on what everything looks like, & will do so when I get back to the coast (where car lives year round : )

https://rennlist.com/forums/gt4/9483...ailure-57.html

G-forceGT4

In your last photo with the black arrow, if you pull back the black plastic adjacent & below your arrow, you'll see a large "hidden" bolt hole. The other one I used to secure welded flange, is the same size & it's where that black strut from the chassis is mounted along with the windshield wiper assembly.

The passenger or left side has 3 "hidden" bolt holes as well. Open up the black air box & you'll see one of them. The others are a bit more "hidden" & I'll just indicate them when I put some arrows on the photographs. Which program btw did you use to do that?

BillC3

The problem is not a manufacturing defect. As far as anyone can tell, it was manufactured properly according to Porsche's design. The problem is a design defect -- they just didn't design it properly to fully handle real-world loads.

d00d

This.
Odd that they didn't reinforce it with an inverted cup insert like the rear.

jmartpr

One of the product I import is made of Aluminum and from Germany.....very nice manufacturing and quality....all of a sudden the products, which are subjected to a lot of stress started to fail. We had this going for 2 years! The manufacturer denied a flaw but did replaced all of the products....long story short at the end the cause was contamination of the Alloy which resulted in random failures of the items. I wonder if we are having the same problem here as we can't pinpoint what is causing them to fail.
I have been tracking my car since new, our roads over here are awful...so far I have been lucky not to live this issue. Then I read about these issue from cars with less use/mileage than mine under less severe circumstances.
IMHO, and I'm no engineer, if this was a design flaw I think we would see this problem popping all over the place every week so has to be something that affected certain cars and PAG can pinpoint to which ones are affected, hence the warranty denial....would have to replace all of them!

sonorous

We can't really say whether this is a design or manufacturing non-conformance without a root cause analysis. We simply do not have enough data.

Very often in cases like to these, the root cause is not so absolutely black and white to define it as a pure design or manufacturing issue. When designing a component, an engineer is supposed to identify all of the risk areas in the design that could result in a functional failure. The engineer then adds controls to the critical features and parameters mitigate those failures. But this is a human process and it is certainly possible to overlook a function or control. Also there are assumptions made, like a material meeting its specifications or a process being in control. For all of these reasons, a factor of safety is applied to add design margin against failure.

Ultimately a product is validated by building parts and testing them, typically to the extremes in critical areas. But it is never possible to completely test every variant of a component with hundreds of dimensions and tolerances plus material and process variation. This is another reason a factor of safety is applied.

So, it is certainly possible that this failure is related to manufacturing variation from process, material, or something else. This variation could eat into the design margin and manifest as failure. Also the failure does not need to be a high percentage to meet this scenario. For example, a material or process variation could be contained within a small percentage of the components. Then these suspect parts would have to be subjected to maximum stresses i.e. a track curb or a pothole. Combining these factors could result in a very low failure rate.

In cases like these, it could be found that the design should have had more margin, or that the process was out of control. It becomes much more gray than black and white. Often the corrective action would include both design (to add margin) and manufacturing enhancements (to add controls).

d00d

It's a design flaw in that the choice of materials, cast aluminum, is susceptible to porosity and therefore isn't optimal.
Hydraulically formed high strength sheet or forged aluminum would have been better albeit more expensive.

GoKart Mozart

That is a good idea and certainly adds some strength, although is see regular plates that already bolt in to that same boss, so I don't see why you had to weld on another piece to go over the existing one? Unless your plates did not have that feature? See here:




Yes, I've noticed the two hidden bolt holes. The Plates you can buy from Porsche utilize those. My point was merely to show that the left side fails less because it has more meat where the horn bracket is, supporting the theory that strengthening those areas would be the solution.

Agreed, and that would be somewhat of a silver lining, as it would only affect some cars, although we would never know which ones. Seems like less GT3's have this failure and a lot more GT4's, so if this theory is true, it must have been in that time frame. Would be interesting to see the manufacturing dates of the strut tower castings. Castings usually have a date stamp molded in to it. Maybe all those with failures could post them in the database. Doens't seem like that thread in the sticky is getting much traction. Not to stir up a conspiracy theory, but I got a notification of an updated yesterday from a fellow member that was dealing with the failure, and the post never made it in to this thread. Odd.

As I stated above. I think there are solutions to this problem. I might give it a shot. I have an idea that I have not seen yet and if feasible will try make something.