Torsional rigidity of the 914, Differences roof on / roof off / steel roof? |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Torsional rigidity of the 914, Differences roof on / roof off / steel roof? |
Beebo Kanelle |
Jan 5 2019, 08:17 PM
Post
#1
|
Member Group: Members Posts: 248 Joined: 22-November 12 From: Houston, Texas Member No.: 15,177 Region Association: Southwest Region |
Does anybody anywhere know where to find the torsional rigidity of the 914 with the roof off vs. roof on vs. steel roof (916) ?
Thanks in advance. |
Curbandgutter |
Jan 6 2019, 05:13 PM
Post
#2
|
Senior Member Group: Members Posts: 564 Joined: 8-March 13 From: Murrieta CA Member No.: 15,637 Region Association: Southern California |
Hello, I did run some numbers on the torsional rigidity of the 914. Here's the link http://www.914world.com/bbs2/index.php?sho...p;#entry2396780
See POST#10 Bottom line is that the stock 914 chassis is very flexible, 3,326’# per degree from my testing. Although I didn't say it at the time, I ran the numbers with and without the doors and found no real difference. From my "door" tests, it's safe to assume that the roof will not be any different. There is too much flex in the hinges, and latches before the roof and doors begin to provide support. Based on testing, I can say that, other than a full roll cage, that the next best thing is to stiffen the longs. Then, if you wanted more, a welded steel roof like the factory. There is a reason why the factory went with a welded steel roof in the 916. I'm almost to the point where I can test again with the full roll cage in place. Based on modeling, I'm expecting a 10x stiffer chassis now. In testing, I found that one of the longs had a stress crack in it. I don't know if that was just mine, or if most of the 914's out there are running around with cracked longs. |
mepstein |
Jan 7 2019, 10:33 AM
Post
#3
|
914-6 GT in waiting Group: Members Posts: 19,254 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic Region |
Hello, I did run some numbers on the torsional rigidity of the 914. Here's the link http://www.914world.com/bbs2/index.php?sho...p;#entry2396780 See POST#10 Bottom line is that the stock 914 chassis is very flexible, 3,326’# per degree from my testing. Although I didn't say it at the time, I ran the numbers with and without the doors and found no real difference. From my "door" tests, it's safe to assume that the roof will not be any different. There is too much flex in the hinges, and latches before the roof and doors begin to provide support. Based on testing, I can say that, other than a full roll cage, that the next best thing is to stiffen the longs. Then, if you wanted more, a welded steel roof like the factory. There is a reason why the factory went with a welded steel roof in the 916. I'm almost to the point where I can test again with the full roll cage in place. Based on modeling, I'm expecting a 10x stiffer chassis now. In testing, I found that one of the longs had a stress crack in it. I don't know if that was just mine, or if most of the 914's out there are running around with cracked longs. Was the crack at or near the e-brake mount? @Curbandgutter |
Curbandgutter |
Jan 9 2019, 05:10 PM
Post
#4
|
Senior Member Group: Members Posts: 564 Joined: 8-March 13 From: Murrieta CA Member No.: 15,637 Region Association: Southern California |
Hello, I did run some numbers on the torsional rigidity of the 914. Here's the link http://www.914world.com/bbs2/index.php?sho...p;#entry2396780 See POST#10 Bottom line is that the stock 914 chassis is very flexible, 3,326’# per degree from my testing. Although I didn't say it at the time, I ran the numbers with and without the doors and found no real difference. From my "door" tests, it's safe to assume that the roof will not be any different. There is too much flex in the hinges, and latches before the roof and doors begin to provide support. Based on testing, I can say that, other than a full roll cage, that the next best thing is to stiffen the longs. Then, if you wanted more, a welded steel roof like the factory. There is a reason why the factory went with a welded steel roof in the 916. I'm almost to the point where I can test again with the full roll cage in place. Based on modeling, I'm expecting a 10x stiffer chassis now. In testing, I found that one of the longs had a stress crack in it. I don't know if that was just mine, or if most of the 914's out there are running around with cracked longs. Was the crack at or near the e-brake mount? @Curbandgutter @mepstein it was actually about 12" back from the a pillar. See POST 193 in the link below for a picture of the crack http://www.914world.com/bbs2/index.php?sho...6845&st=180 |
Lo-Fi Version | Time is now: 4th May 2024 - 04:59 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |