Original 356 vs vw pan replicas

Who can direct me to a source to compare the structure of Dr. Porsche's 356 chassis and his beetle design?

Interested to see how the tube -frame replicars and the pan -based ones compare to what the namesake car(356)had for a frame.

Here's some interesting reading
http://www.356registry.org/History/index.html

$0.02 worth: the 356 is bent and welded sheet metal in every direction. Rather stiff, I believe, unless and until all those seams and dead volume pockets capture water vapor/condensation and/or salt and start to rust. In my experience w/ these original cars, the only safe place to have them would have been the desert. Or out on the road only on sunny days w/ temps above 60F. Also, the coupes had poor rubber at the windows, and so those leaked eventually too, adding to the problem mentioned above as the wtaer is now on both sides. Basic pan based replicar is a sheet metal piece with a tunnel in the middle. VWs had body section bolted on and away you go. Likewise, basic replicars shorten the pan (cutting, welding) bolt on the FG body and away you go. If body/shell has metal stiffening parts, and they are properly fixed to the pan, then stiffness is improved. In either case total car stiffness is low, relatively. Tube frame improvements build up a front chassis frame that is welded to a part of the pan, which has had its front cut off, leaving just the rear details to mount engine and tranny. Add on a stiffened FG body, and things are going in the right direction. Or: build up an entire tube frame (monocoque) substructure that takes a FG shell, and you get to the best you can do, I'd suppose. Believe the welded tube front end fixed to a cut down pan are very stiff and work well. Also, I have no idea what the experts will say, but will enjoy to hear it.

Kelly; Glad to hear your two cents worth! I see you are having a 2007 JPS built,so I presume those cars are stiff enough for your purposes. Would like this discussion to stay alive here.

Any structure experts out there who'd like to weigh in?

Have read some postings here making reference to JPS car purchasers opting for a combination pan/tube construction. Is that true?

I'm currently driving a 1982 Alfa spider. It really feels sloppy over any uneven roads. I wonder how it would stack up to a pan-based replicar(?) in terms if stiffness and road feel. And again compared to a tube-framed Speedster (SAW,Beck,Intermeccanica)?

Comments?........

Correct: My JPS will be made with a tube-welded forward section sub-frame, and the remnant pan piece at the back. The JPS shell is also steel reinforced, BTW. Believe this to be a very stiff car when done, and should fully meet any driver's standard, except perhaps someone into racing full time, or running the Baja 500, or whatevere that race is called, over surfaces that are not really roads. One can weld in a roll bar structure that has fore-to-aft bracing and a lateral member that makes a box frame structure just behind the seats, and this raises stiffness too. [I am not talking about roll bars seen that are strictly cosmetic, and bolted to the car.] I have seen, and you might be able to find in this Forum, pictures of a brace set at the aft corner of the door openings. These are a bit in the way for ingress/egress, but do add stiffness. What is it you intend to do here, anyway? I can't comment on the nature of nor the reasons for your other ride being so sloppy on a bumby road. Never been in one of those cars. . .

I've only ever offered a couple opinions on the subject, but I've got a bit more practical experience now than I did the last time this came up.
Kelly's probably summarized the biggest differences between the two. Since mine started out as a pan chassis and is now a tube jobber, I'll have to add to that that the pan was really noisy. I don't know if the lack of any sound-deadener was the culprit, but it seems to me that the tube cars are a whale of a lot quieter going down the road.
My pans weren't the best, probably indicative of a car that's had a few owners, but it sounded like I would imagine it sounds to be stuck inside a snare drum when the marching band is playing. Every little bump or hitch in the road sent a tapping noise or a hollow, windy sound through the car.
I don't have that problem now, but that might be because of the gauge of metal I'm using for floors or the dozens of rivets I'm using to hold my interior sheet metal in place.
I would have thought that bare tubing with sheet metal riveted on would have been a lot noisier than a tub mounted onto a pan, but that doesn't seem to be the case.
Also, I moved a Tubaru this weekend and Henry took me out in an Intermeccanica -- both cars made no noise to speak of. They were more reminiscent of a yacht's engines in a harbor; no squeaks, rattles ... none of that.
It may come down to the quality of the pan build. Mine was not nice.

Well, What I intend to do is somehow replace the Alfa with yes, a speedster. I had a '73 914 up til about a year ago.That was a very stiff car and loud without considering the Bursch exhaust I added.

Will be looking at builders this summer:TN,LA, etc....!

Peter, the pan/tube religious wars have pretty much ended with the realization that, when proiperly built, there is no discernable difference between them. I drive a Beck, which is tube framed. This weekend I drove Gordon Nichols CMC with its tube reinforced pan. Gordon's car is set up for autocross and is really sweet. I couldn't tell any difference due to the frame. Buy what you like from any one of the major manufacturers and you'll be very happy.

Peter,

Mine this Forum for all it is worth -- which is a lot. Do your homework, and then talk to the builders, all of whom mentioned here seem to be pretty straight shooters. See the locked post at the front of the Newbie section and get some very practical advice. Try to get firm grip on what you want the car to do/be, and talk to some owners to see if what you want it to be matches w/ what they actually are. Some will say, buy used first to limit financial exposure, drive it around and see how it all goes. They will also say that most used cars listed are low miles and usually in decent shape. Some are pristene, and the old hands here seem to know which ones they are. There is much listed here in SOC Classifieds, and many SOCers track e-bay and other sources, just for the hell of it, I guess. If you buy used and then want more/differnt, they say further that you can usually sell for what you paid +/-, and can then go buy a new one, just the way you want it. All good advice. I followed none of it, as I have owned two real Coupes many years ago, and thoroughly understand air cooled engines and oversteer. I had a buddy w/ a real Speedster a long time ago, and rode around in that for many happy hours. Plus, life is short, and I was pretty sure just what I wanted. So I visited w/ John Steele at JPS, kicked his tires, literally, rode in his car and became sold on his sincerity and the worthiness of his builds. His fit and finish (paint) is very fine, and John is a bit of a perfectionist. Following along with the life is short idea (too short to drink cheap wine/beer, etc.) I opted for all the engine John can do (2332 cc) and the tough tranny, the aforementioned tube chassis add-on, independent rear suspension, 4 wh. disk brakes and large sway bars as the basic package. Now, if I can just get the car made and delivered, I will be a happy camper.

Keep us posted on how your build/buy goes.

Hope I don't send this reply twice by accident.

Really appreciate the feed back from you guys. Very welcome to hear you say the tube-pan wars are over. It isn't evident at first from reading the literature from the various builders.

Personally, I'm strongly attracted to the vw/porsche geneolgy, yet I see some have traded their pan cars for a "Tubaru". That is a compellingly-made engineering argument for those who are not emotionally in thrall to the descendents of the wizard of Zuffenhausen.

Now that I near 50yrs. I'll probably ignore all the practical advice and purchase a new speedie."Can't tell me nothin'",as the song says.

I look forward to visiting the So. Cal builders this July and will be in the Smoky Mts. in August, so I can see that "other" approach to speedster art.

In the meanwhile I'll stay on the sidelines and enjoy the fun of being a wannabe speedster owner.

Thanks again, Peter(Lurker).

Welcome to the madness, Peter. Be careful - it's addictive.

The Suby Tubs (as they are called sometimes) offer a lot in terms of peformance (many HP and ft-lbs), reliability, smog control and so forth due to FI and electonic control of the system. You get a radiator w/ all of that, which might be good or bad, depending on how you like that maintenance. Heat is supposed to be much better w/ water at your control. Looks to me like you lose the back seat, so there are trade-offs. For me, I am a traditionalist, and I don't mind tinkering. The air-cooled VW arrangement is a simpler machine basically, and eminently more shade-tree fixable. Some will like that, some won't. Ultimately, for me, the car has to sound like the original, and that means the fan noise mixed in w/ the growl out the exhaust and the carbs doing their thing. I owned two original Coupes once upon a time, and it is that nostalgia that is important to me. You may be coming from a different place. From what I can gather here, one thing seems certain: once you get this toy, you are going to love it.

I'm with you 100% Kelly; I come from the same place too...no a/c, no radio, old school and just like the originals; that's definitely part of their appeal.

Yeah, that pretty much descibes me too, a traditionalist.

So that's what makes the music; fan whine, carbs and the dry growl of air-cooled alloy metal. That's so primal.

Ummmm, don't forget the fiberglass.