2025 Taycans - fiberglass composite underbody guard?

[chun]

Pretty well everything you write here is wrong.

I was one of the pioneers of the use of composite materials in Formula 1 over 40 years ago and have considerable experience of the use of different fibres and resins as well as most engineering alloys.

Glass fibre is nice and cheap and flexible, that is about it.
If the bottom of the battery takes a vertical impact the fibreglass won't protect anywhere near as well as aluminium but also will not show it since after considerable deflection it will spring back and any damage to the cooling will not be seen from outside.

Weird. In my industry, it is used for reactors. It handles impacts much better than steel, according to what I know. It of course, matters what kind of impacts. 90degrees high force, sharp, speed, sure... it won't be much better than paper.

Most plane manufactures also use fiber glass composites for a lot of their aircraft parts that are expected to go through mechanical impacts as far as I know, so it can't be as bad as you make it out to be, no?

Now, I don't know what Porsche used, but strength varies a lot depending on the quality of glass fibers being used. If they use any reinforcements or not,Amount of layers, if it has been through a heat treatment, orientation, resin quality, all of these will result in different resilience to mechanical impacts.

You are also describing "vertical impact". But that's not really the kind of impact that cars get on the underbelly, is it now?

We're also not comparing it to aluminium. We're comparing it to the steel sheet using by j1 taycan.

From my own experience with it, I continue to believe it is better, marginally as stated initially.

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[chun]

What about a steel bar or bolt that gets picked up by a tire, bounces under the car and gets stuck between the road and the underbelly (the cover of the battery in this case).
That'll be pretty vertical...

It's also the kind of impact that would go through the steel sheet also. I doubt that's the kind of impact porsche is targeting with this change, as they are very rare. Also, what kind of nail is small enough to be picked up by the tire but big enough to get stuck between road and underbelly?

I did mention "90degrees high force, sharp, speed, sure... it won't be much better than paper." But more likely are road bumps, speed bumps, stones, curbsides, inclines and the like, and on those, the fiberglass composite will outperform the steel sheet

 

[rb33gl]

The impact I'm most concerned about is where the weight of the car could result in deformation, such as driving over an elevated speed hump. The front wheels will raise the car but then the 2.3 tonne weight of the car could bear down on the hump with a huge force, easily sufficient to deform a 3mm sheet of steel, partularly if there are irregularities in the hump (such as it being made of cobble stones as found in places in the UK).

I don't think there's any solution to this. It's a consequence of the location of the battery and its cooling ducts being in the vulnerable area. Porsche's answer is to raise the car temporarily, but you may not see the danger (especially in the dark) and by then it's too late.

Not sure I would be more comfortabe if it were made from fibreglass or aluminium either.

 

[f1eng]

It's also the kind of impact that would go through the steel sheet also. I doubt that's the kind of impact porsche is targeting with this change, as they are very rare. Also, what kind of nail is small enough to be picked up by the tire but big enough to get stuck between road and underbelly?

I did mention "90degrees high force, sharp, speed, sure... it won't be much better than paper." But more likely are road bumps, speed bumps, stones, curbsides, inclines and the like, and on those, the fiberglass composite will outperform the steel sheet

I only used the 90 degree impact protection because that is what would be necessary to produce the dent in the floor which lead to a very, very, very long thread about cooling channels being damaged.
Probably a rare type of impact.

For just speed bumps and so forth scuffing the floor the biggest advantage of fibreglass over metal is weight, not protection.

We only used fibreglass for trim like bodywork, as does the aircraft industry, interior panelling for example.

Except in complex laminates, unlikely in a road car shield, composites are inferior to metals. It is very expensive indeed to replace metal with even an equally performing composite.

 

[Dee]

and on those, the fiberglass composite will outperform the steel sheet

Fiberglass composite will only outperform steel in weight saving, not in protection.
Even PP-plastic would outperform steel in that case if you consider that a performance indicator.
Other factors are more relevant, like thickness and costs.

 

[chun]

I only used the 90 degree impact protection because that is what would be necessary to produce the dent in the floor which lead to a very, very, very long thread about cooling channels being damaged.
Probably a rare type of impact.

For just speed bumps and so forth scuffing the floor the biggest advantage of fibreglass over metal is weight, not protection.

We only used fibreglass for trim like bodywork, as does the aircraft industry, interior panelling for example.

Except in complex laminates, unlikely in a road car shield, composites are inferior to metals. It is very expensive indeed to replace metal with even an equally performing composite.

So you are saying Porsche decided to intentionally make the battery and HVAC system more prone to damage? That will eventually result in a class action lawsuit at the first freak accident, and a massive recall, as it happened to Tesla.

I somehow doubt Porsche would take a chance on that...

I maintain my view that for the kind of impacts the shield will get, a composite that can disperse the shock all alongside its body and not be permanently deformed will be better.

 

[kele]

I imagine that Porsche knows the true scale of problems with the 2020-2024 shield and knows what it can do to car sales. My bet is on them trying to improve the reliability (and shed the weight of course). We'll know once more 2025 cars will hit the roads.

 

[Murph7355]

I imagine that Porsche knows the true scale of problems with the 2020-2024 shield and knows what it can do to car sales. My bet is on them trying to improve the reliability (and shed the weight of course). We'll know once more 2025 cars will hit the roads.

I'm way more cynical.

Cost first. Weight maybe.

I was curious what the pack is made up of - there's a teardown video on here ( (21) Taycan Battery Pack Teardown | TaycanForum -- Porsche Taycan Owners, News, Discussions, Forums) that was interesting.

Looks like the primary function of the skid plate is to protect the cooling channels for the battery. The cells themselves have the skid plate, the battery tray (chunk of metal) and a case (chunk of metal). I would think they're designed to take significantly great impacts than would ever be likely from underneath.

Maybe something catastrophic could happen if the cooling channels were fractured?

Which then got me wondering why they put them on the bottom of the pack and not the top. Maybe proximity to airflow/colder air? Keeping the passenger compartment cooler?

 

[Fish Fingers]

Now I’m now saying car manufacturers always get it right….
Buy surely us mere mortals just have to trust that Porsche know what they are doing….

You could also say that a publicly quoted companies no 1 objective is to make as much profit as possible (within the law) for it's shareholders.

Start there and then work other factors in.

Its why Rolex is pretty unique as a charitable foundation.
They look longer term - more than short term profit.

 

[Dee]

So you are saying Porsche decided to intentionally make the battery and HVAC system more prone to damage? That will eventually result in a class action lawsuit at the first freak accident, and a massive recall, as it happened to Tesla.

FYI: There is a recall for the battery (ANA4) and the heater.

 

[f1eng]

So you are saying Porsche decided to intentionally make the battery and HVAC system more prone to damage? That will eventually result in a class action lawsuit at the first freak accident, and a massive recall, as it happened to Tesla.

I somehow doubt Porsche would take a chance on that...

I maintain my view that for the kind of impacts the shield will get, a composite that can disperse the shock all alongside its body and not be permanently deformed will be better.

You maintain whatever view you like

For me it is probably mainly part of the tiny weight reduction they have achieved, and, like all impacts, we never get 2 the same, so it is unlikely to be better or worse protection for all incidents and is less likely to show damage even if it is there.

 

[Scandinavian]

Which then got me wondering why they put them on the bottom of the pack and not the top. Maybe proximity to airflow/colder air? Keeping the passenger compartment cooler?

I have had the same thoughts, why not on top of the battery pack. Would be more logical from a Cooling point of view.
Only reason I could think of was that if there is a leak, it would leak into the battery. And that may not be the best friends mixed, water and electricity??

However they could maybe have accommodated the cooling plate inside the heavy battery frame that protects the battery modules?? Seems strange to have a flimsy cover protecting some very sensitive cooling fins/channels??

Guess we will never know from Porsche

 

[Boss Hogg]

Are you talking about the drainage holes? Yes, those are still present, but they don't lead directly to any of the electrical bits or HVAC conduits. Otherwise what holes exactly are you talking about?

The rubber bits on the drainage holes are not really so water doesn't go in there, it's so bugs or other sort of road sh*t doesn't get in there, and i'm quite sure I read that porsche started advising dealers to remove those upon delivery of cars, so either way not relevant

I was talking about the drainage holes but I have rechecked and they still have rubber covers, although these seem like full covers/grommets.

There are however several small new holes, c. 10mm diameter, that are complete holes where water and other stuff will get inside.

 

[Boss Hogg]

My theory, for what it's worth, is that the new reinforced whatever base plate will act more like a kevlar vest, flexing and dispersing a fast, small impact rather than denting at the impact point.

There is a clear cross weave pattern and there are noticeably fewer fixing points that should let it flex more vs previous.

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