2417 is now sandblasted and undergoing minor panel work due to rust. I would like to ask the forum if it would make sense to weld reinforcement panels to stiffen up the body of a street car. If yes, where? I‘m only interested in reinforcements that are not that visible at first glance, as I am looking for originality.
Original Post
......and on the same topic: Is Dr. Innocenti's Pantera a good case to seam weld the monocoque chassis? Is it cost effective compared to much more visible frame reinforcements?

Curious, Chuck Engles
I got these shown below from ebay years ago in case I got another Pantera to build along with the wifes divorce papers. My cars have them welded in the area behind the rear window. They have a slight curve to them, and measurements are shown in case maybe you could make some. I hear reinforcements should also go near the corner windshield and around the tail lights; although others here undoubtedly would know more about where are these areas are and how to reinforce them.
MetalReinforcements by JanDaMan, on Flickr
There is a great thread about building a Group 4 replica in which suspension bracing was discussed and illustrated.

Building a Group 4 Replica

If you can, why wouldn’t you?

Same with seam welding... why not?

This is your only chance to do it - you won’t do it after paint.

What’s a couple more weeks of fabrication, and a couple thousand Reichmarks.... (Seriously)

Originally posted by Rocky:
Kan -

Is that your ex-wife?

Nice reinforcements!


Haha, no. If that was the ex-wife it wouldn’t be ex!

Is that rear fender area a reinforcement or is that just how the original Panteras were made?
As I understand it the cracking in the usual places around taillights, A pillar at the lower windshield and rear decklid at the curvature near the gills is predominantly due to work hardening of the lead filler over the years. It would be prudent to remove the lead and refinish these areas.

If your vision of originality is to maintain the original (non adjustable) chassis cross brace then some welded in reinforcement would likely help prevent future chassis flex and cracking.
First of all thanks to all of you for chiming in. So far I`ve decided to seam weld the areas that I think will be subjected to flexing but also weld reinforcement plates in critical areas. As far as I`ve understood the critical areas are at the bottom of the A pillars, the area between the back panel and the rear fender, the area below the gills and the area suggested by JanDaMan. The chassis cross- brace will remain in place. Any other areas you would suggest? Should any other work carried out while the body is unpainted?
I am planning on moving the seat rails 2 or 3 cm to the right to line up the seat with the steering wheel. Any thoughts on this. ?
JFFR in Wilcox, AZ has added stiffener plates on the jacking points on his car, and has tied those into the structure underneath.

You should send him a PM, and see if he can get you his description and some pictures.

Originally posted by Eugenio Innocenti:
Thanks Rocky!

These help too so your deck lid doesn't bounce around on the sides; although I have seen center locks that have a long bolt up through them in which the decklid slides down onto which may help just as well.
Custom decklid bumpers by JanDaMan, on Flickr
Originally posted by Eugenio Innocenti:
...I`ve decided to seam weld the areas that I think will be subje...

If you can, some photos of the areas and additions you make would be greatly appreciated

maybe this set of photo might help


Images (1)
The Pantera body panels are made of thin metal. Not much structural strength to them. Overall the Pantera chassis seems to be stiff. When I jack it up, it doesn't sag like other cars. But there are four problems.

Most mid engine cars have some serious cross braces in the engine compartments. Not the Pantera. The rear of the Pantera twists and wags (like the tail of a dog). This causes cracking around the tail lights and near the rear deck lid hinges. It is my understanding that chassis stiffeners prevent the twisting and wagging, and eliminate the problems causing cracking in those two areas.

The mounting points of the upper rear control arms collapse inward. This throws off the rear camber, and makes it hard to set because it changes when the car is set on the ground. Rear camber can eventually become impossible to set because the control arms run out of room for adjustment shims. People install spreader bars and adjustable upper rear control arms to compensate. I think some sort of brace could be fabricated to stabilize the distance between the upper control arms, but it would require more than the single attachment point of the factory spreader bar.

The lower A pillar mounts are the final problem, where too much force is applied over too small of an area of thin metal, thus flexing occurs which leads to cracking. I don't think the forces transmitted through the A pillars can be reduced. I assume that means the attaching points need to be strengthened, thickened, or spread over a larger area.

My Pantera has cracking around the tail lights. I've been told the cross brace in the attached picture, although small, is effective at removing most of the twisting that caused the cracking. So I bought one. I've had my eye on the PPC rear stiffener to deal with the wagging. Its 3 foot long and attaches to the chassis under the car. Sorry no picture of that one. Precision Proformance sells something similar.

One of my Pantera's A pillars has a crack where it attaches to the cowl. I'm not aware of a "bolt-on" that can strengthen the attaching point however. This requires welding something in place to strengthen the area, and then the crack can be repaired. I guess I'm living with the crack for now.


Images (1)
Last edited by George P
Here is what I did:

- I "doubled" the spars under the car with rectangular tubes of 40x27 mm

- I made these reinforcements in the engine compartment:

- finally the bottom sleepers, inspired by what we find in the trade:

And as I have to replace the rocker pannels, I am installing a longitudinal folded sheet reinforcement that will be welded all the way inside and will be totally invisible. (I have not done any pictures yet)

I'm not a professional welder, it shows, but it's resistant anyway. Smiler

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