I thought the early 550 chassis was more similar to the beck, which is a 3 inch tube ladder frame, I think. But didn't porsche continually make changes to the 550, I thought I read that after 55 or 56 the 550 was built on a space frame. I'm not an expert on the orginal 550's, but I remember reading the first few were hurridly assembled because porsche wanted something faster than the 356 to race with. At any rate, I can assure you I don't care enough about this to try to twist the arms of 3 vendors to allow me the privilage of working for them free of charge.
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Hi Manuel;
I have not researched the original 550's much to know what frame revisions were done as the car aged. I do seem to remember seeing that the frame tubes were welded aluminum and must have been prone to cracking even as late as the 917 chassis. I have analyzed a few welded aluminum tube structures at work and the problem with welding aluminum is the heat effected zone has a reduced stress allowable.
Of the 3 vendors, I believe that the Vintage would welcome a stiffness comparison to the Beck since their web site touts their frame design. It would be an interesting technical exercise, but I doubt that the 3 vendors would supply the needed info for analysis.
I have not researched the original 550's much to know what frame revisions were done as the car aged. I do seem to remember seeing that the frame tubes were welded aluminum and must have been prone to cracking even as late as the 917 chassis. I have analyzed a few welded aluminum tube structures at work and the problem with welding aluminum is the heat effected zone has a reduced stress allowable.
Of the 3 vendors, I believe that the Vintage would welcome a stiffness comparison to the Beck since their web site touts their frame design. It would be an interesting technical exercise, but I doubt that the 3 vendors would supply the needed info for analysis.
George W;
I couldn't and didn't say it as well as you did. That is what interested me about The McRae chassis. When Manuel has a few years of reality under his belt, he will maybe come close to brusing up against reality. The engineering schools are good and their students are pretty good, but nothing beats about 20 years of actual experience.
After graduating Purdue, yes in engineering! I wasn't worth a damn for the first 5 years, then I finally got I didn't know everything. Then the learning begun. Manuel learn a lession from an old M.E., get over it.
It is my dream to build a really fine (Modern underpinnings)RS 60 or 550 "A"" RS with a modern space frame or monocock chassis to have the traditional looks but with performance and road holding the 1955 Porsche factory designers could have only dreamed of acheiving. 4 wheel independant suspension and 4 wheel disk brakes naturally. The burning question is in my mind at least will enough folks enjoy it that it could support long term buildout. Right now I'm not too sure the understanding would be enough. Time will tell.
I'll address the 550 handling problems and yes the "A" was a vast improvement over the 550... "Three distinct problems in the Spyders were addressed by the factory at the same time, in late 1955. The "flexible flyer" handling of the original car (550) was due to chassis distortion in both the longitudinal plane - flex along the fore-to-aft ladderbeams - and torsional movement - a twisting of the entire assembly." Porsche 356 & Spyders by Gorgon Maltby, Page 129. It goes on but you get the idea.... The "A" was a vast improvement.
I couldn't and didn't say it as well as you did. That is what interested me about The McRae chassis. When Manuel has a few years of reality under his belt, he will maybe come close to brusing up against reality. The engineering schools are good and their students are pretty good, but nothing beats about 20 years of actual experience.
After graduating Purdue, yes in engineering! I wasn't worth a damn for the first 5 years, then I finally got I didn't know everything. Then the learning begun. Manuel learn a lession from an old M.E., get over it.
It is my dream to build a really fine (Modern underpinnings)RS 60 or 550 "A"" RS with a modern space frame or monocock chassis to have the traditional looks but with performance and road holding the 1955 Porsche factory designers could have only dreamed of acheiving. 4 wheel independant suspension and 4 wheel disk brakes naturally. The burning question is in my mind at least will enough folks enjoy it that it could support long term buildout. Right now I'm not too sure the understanding would be enough. Time will tell.
I'll address the 550 handling problems and yes the "A" was a vast improvement over the 550... "Three distinct problems in the Spyders were addressed by the factory at the same time, in late 1955. The "flexible flyer" handling of the original car (550) was due to chassis distortion in both the longitudinal plane - flex along the fore-to-aft ladderbeams - and torsional movement - a twisting of the entire assembly." Porsche 356 & Spyders by Gorgon Maltby, Page 129. It goes on but you get the idea.... The "A" was a vast improvement.
Joe;
I also agree the Vintage is a better build, higher fit and finish from the showroor, well so to speak.
Before the current owner purchased the business (Vintage 550 Spyders) there was considerable interest by the then owner in re-engineering the frame to make suitable and important improvements, featuring IRS rear suspension and other major improvements.
I do not wish to embrass the engineer or the people involved, but it was desided that it just wasn't that important by the then owners. I couldn't disagree more, too bad the oppertunity was missed at that time. Of the two frames, there is no doubt that I personally like the Vintage frame better and I also state that it is only marginally better than the Beck, but you (as a driver) would really have to hang it out on the track to tell the difference and we all know most owners are not racers, but more into looking good and cruising in style which all current offerings do very well.
So for most of the Spyder group, it really doesn't matter; you either drink the Vintage Cool-Aid, or the Beck Cool-Aid or the Thunder Ranch Cool-Aid. There is no shame in owning and driving any of the offerings currently on the market, the idea is to have fun after all.
I also agree the Vintage is a better build, higher fit and finish from the showroor, well so to speak.
Before the current owner purchased the business (Vintage 550 Spyders) there was considerable interest by the then owner in re-engineering the frame to make suitable and important improvements, featuring IRS rear suspension and other major improvements.
I do not wish to embrass the engineer or the people involved, but it was desided that it just wasn't that important by the then owners. I couldn't disagree more, too bad the oppertunity was missed at that time. Of the two frames, there is no doubt that I personally like the Vintage frame better and I also state that it is only marginally better than the Beck, but you (as a driver) would really have to hang it out on the track to tell the difference and we all know most owners are not racers, but more into looking good and cruising in style which all current offerings do very well.
So for most of the Spyder group, it really doesn't matter; you either drink the Vintage Cool-Aid, or the Beck Cool-Aid or the Thunder Ranch Cool-Aid. There is no shame in owning and driving any of the offerings currently on the market, the idea is to have fun after all.
Hi Jim;
I did not want to get in any flame wars with Manuel or anyone else. I just enjoy good technical discussions. I have been doing Structural Engineering since 1973, and I did get a BSME in 1983 after many years of night school (I had another BS degree in 1971). I was trying to impart some structural observations to Manuel that you don't need months of finite element modeling work on a $40k program to get a feel for how a structure will perform. You can make an "educated guess" on which frame will be stiffer.
As far as your quest to bring a more modern spyder to market, I wish you much luck and I agree with your concept. Added competition may improve the other vendors. You might have more luck with a kit concept than a full turnkey car. Point the buyer to where they can get the 5 speed transaxle IRS, disc brakes, modern engine, etc and let them taylor the car to their own preferences of performance. If they want a 650 hp Porsche flat 6 in a 1200 pound car, it is up to them. If they are happy with a stock 40 hp 1300cc VW then they will have the best handling 40 hp car on the road.
I did not want to get in any flame wars with Manuel or anyone else. I just enjoy good technical discussions. I have been doing Structural Engineering since 1973, and I did get a BSME in 1983 after many years of night school (I had another BS degree in 1971). I was trying to impart some structural observations to Manuel that you don't need months of finite element modeling work on a $40k program to get a feel for how a structure will perform. You can make an "educated guess" on which frame will be stiffer.
As far as your quest to bring a more modern spyder to market, I wish you much luck and I agree with your concept. Added competition may improve the other vendors. You might have more luck with a kit concept than a full turnkey car. Point the buyer to where they can get the 5 speed transaxle IRS, disc brakes, modern engine, etc and let them taylor the car to their own preferences of performance. If they want a 650 hp Porsche flat 6 in a 1200 pound car, it is up to them. If they are happy with a stock 40 hp 1300cc VW then they will have the best handling 40 hp car on the road.
George and Manuel;
No slight intended. George it is totally evident to me that you know from which you speak as it is also evident the Manuel is still quite wet behind the ears, awful young and totally full of himself.
Duly noted that all those things mentioned are not sins, for sure, actually it reminds me of me back when I knew everything. I didn't have any experience but... well you know. "Time wounds all heals."
When Manuel has 10 years in the field of his choice, he will no doubt know that he knows nutin' at all, and then the learning can begin.
Hey Maunel, I'm picking on you, and havin a little fun, but there is some grain of truth in what I'm saying, I mean no offence.
Also keep in mind that 4% of all engineers make a real difference in the world, 80% get by doing a fair job while earning a good living and 16% will leave engineering within two years. You just can't take yourself too seriously, God knows I've learned that lesson the hard way.
No slight intended. George it is totally evident to me that you know from which you speak as it is also evident the Manuel is still quite wet behind the ears, awful young and totally full of himself.
Duly noted that all those things mentioned are not sins, for sure, actually it reminds me of me back when I knew everything. I didn't have any experience but... well you know. "Time wounds all heals."
When Manuel has 10 years in the field of his choice, he will no doubt know that he knows nutin' at all, and then the learning can begin.
Hey Maunel, I'm picking on you, and havin a little fun, but there is some grain of truth in what I'm saying, I mean no offence.
Also keep in mind that 4% of all engineers make a real difference in the world, 80% get by doing a fair job while earning a good living and 16% will leave engineering within two years. You just can't take yourself too seriously, God knows I've learned that lesson the hard way.