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Discussion Starter #1
Hi guys, it occurred to me that since I have a bare shell and a MIG welder and I is easier for me to invest time rather than cubic dollars now is a good time to ask if seam welding is a good thing to do. She will be a road car.
 

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What model are we discussing? This question appears in the GT section but you list owning a 73 spider. To my mind there might be two different answers.

The common wisdom is that seam welding is a good thing for a race car to improve strength and stiffness but not recommended for street cars as it may prevent the designed-in crumple zones from doing their job in the event of a crash I'm not sure if I buy that second part. The spider and GTV, although appearing be designed to absorb energy to protect the passenger compartment, probably don't rely on the joints being spot or seam welded to do so. Digital finite element analysis (FEA) was in it's infancy when these were bodies designed. I suspect the primary energy absorbing mechanism is deformation of the body structure and not tearing or rupture of the welds. That's a very esoteric analysis to do without FEA.

To cases: A GTV certainly doesn't need to be seam welded for street use. I run my GTV in the occasional track session on delightfully sticky tires and the chassis is plenty stiff to handle it. On the off chance that my explanation above is hooey at best seam welding would provide little benefit and at worst might compromise crash safety.

The spider may be a different story. The chassis isn't as stiff as the coupe. The Ereminas chassis reinforcement/stiffener is on the market for a reason. If you are going to be putting oversize and sticky tires on it seam welding might provide a noticeable handling benefit albeit at some unquantified risk of reducing crash safety.

With any luck we may get other responses with violently different opinions.

Good luck with your project!
Bob Stewart
73 GTV
 

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Discussion Starter #4 (Edited)
Hi guys, thanks for the responses. I was actually asking about a Stepnose (I need to update my signature, sorry). This is the $500 shell I found in a local junk yard that I posted on earlier.

I partially seam welded my TR8, adding some welds every couple inches on key joints, and it made a quite noticeable difference in how stiff the shell was based on feel and handling.

If the GT bodies are plenty stiff as they came from Alfa then that frees me to do the one of the other thousand things that I need to do on her. Any all said, I am still inching to do it. Ha.

Thanks of the coaching.

EDIT - just found another thread that suggests front an drear have crumple zones but seam welding the main cabin would actually make it stronger. Hmmm.
 

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Congratulations on your step nose!

Although I love my '73 dearly I would be among the first to admit that Giorgetto Giugiaro and Bertone did it right the first time. Virtually every styling change from the step nose to my 73, smoothing the nose, the grill (shudder), side marker lights, etc., were a clear step in the wrong direction as far as looks go.

Have fun restoring it!
Bob S.
 

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I partially seam welded my TR8, adding some welds every couple inches on key joints, and it made a quite noticeable difference in how stiff the shell was based on feel and handling.
Have you checked out Daron Walker's video on YouTube? You'll have to look for it but he has an excellent discussion on seam welding a 105 Alfa, showing what needs to be done, etc. in his videos. Look for Vintage Customs Alfa on YouTube.

No relationship, except that Daron's a friend.
 

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Respectfully disagree

Congratulations on your step nose!

Although I love my '73 dearly I would be among the first to admit that Giorgetto Giugiaro and Bertone did it right the first time. Virtually every styling change from the step nose to my 73, smoothing the nose, the grill (shudder), side marker lights, etc., were a clear step in the wrong direction as far as looks go.

Have fun restoring it!
Bob S.
I have to respectfully disagree, and at the risk of highjacking this thread, state (completely subjectively of course) that the evolution of the GT to GTV from step nose to 74, (or later for you Europeans!) was nearly perfect. They took a simple, and very "right" design and evolved it very nicely to update it in an elegant way while still maintaining the original silouhette, culminating in that so very 70's grille on the 74's. Not my cup of tea, but in 1974, much more current, and yest just as timeless overall, as the original step nose cars.
-except for those darn U.S. side markers. I agree 100%, they were and always will be horrible!
: - ). Just my $.02!
 

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Discussion Starter #11 (Edited)
Putting aside the optimal model year in the series for a moment (I am sure it will flair again) - your help and some research has flagged the less robust front suspension and crossmember mounting point as consideration.

Does anymore remember the title of the video from Vintage that covers seam welding, I've watched a couple and while interesting I haven't found the right one yet.

For those that have done this reinforcement is the steel plate flush against the factory metal or is their an air gap that you want to leave? Hard to tell from the pictures, thanks.

 

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Bumping an older thread to see if anyone has any thoughts or input. My 72 GT 1300 is destined to be a street legal track day car. EDIT - I plan to install a full cage. It's currently completely disassembled, and almost completely stripped of paint, undercoating, etc, so now is the ideal time to seam weld and reinforce the chassis.

Curious to hear if anyone has any input on where and what to reinforce or weld.

Thanks!

Scott
 

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From another thread:

"I don't think a GTV needs further stiffening either. Many racers seem to reinforce the inner wall around the steering box attachment bolts, ditto the idler, as well as adding gussets to (or seam-welding) the brace under the sump. Of course, a full roll cage will also further refine matters but for normal road use this just isn't necessary. As a mark of how stiff a good chassis can be, I once lifted my car onto four axle stands on a slightly uneven surface, and there was a clear 0.5" gap between the chassis and one of the stands, no sag at all. Quickly remedied with a block of wood, though."
 

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Curious to hear if anyone has any input on where and what to reinforce or weld.

Seam welding coupled with judicious reinforcement definitely makes a difference. On our spring tour, I rode in a friend's seam welded, modified 2 liter Super. My friend Bob, an experienced race driver, was doing the driving and repeatedly praised the car's feeling of precision during turn-in. From the passenger's seat, I could also feel the difference. Seam welding coupled with a good suspension makes a difference. As long as you have the car stripped, do it.
 

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Seam welding coupled with judicious reinforcement definitely makes a difference. On our spring tour, I rode in a friend's seam welded, modified 2 liter Super. My friend Bob, an experienced race driver, was doing the driving and repeatedly praised the car's feeling of precision during turn-in. From the passenger's seat, I could also feel the difference. Seam welding coupled with a good suspension makes a difference. As long as you have the car stripped, do it.
Appreciate the details. If anyone has any tips on where/how, please post!

Thanks,

Scott
 

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