 Tubular Space Frame?, How would you do it? |
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| URY914 |
 Mar 9 2010, 07:44 AM
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#21
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I built the lightest 914 in the history of mankind.  Group: Members Posts: 130,443 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None  |
500hp puts you in a different crowd than my car. Here are I few that I've found over the years.....
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| URY914 |
Mar 9 2010, 07:45 AM
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#22
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I built the lightest 914 in the history of mankind. Group: Members Posts: 130,443 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
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| URY914 |
Mar 9 2010, 07:47 AM
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#23
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I built the lightest 914 in the history of mankind. Group: Members Posts: 130,443 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
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| URY914 |
Mar 9 2010, 07:53 AM
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#24
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I built the lightest 914 in the history of mankind. Group: Members Posts: 130,443 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
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| URY914 |
Mar 9 2010, 07:55 AM
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#25
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I built the lightest 914 in the history of mankind. Group: Members Posts: 130,443 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
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| URY914 |
Mar 9 2010, 08:03 AM
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#26
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I built the lightest 914 in the history of mankind. Group: Members Posts: 130,443 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
I have more pictures but I'd have to spend the next day scanning them. As you can see, everyone has thier own ideas on how to do it. There is no right way or wrong way just different ways. (IMG:style_emoticons/default/sawzall-smiley.gif)
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| rick 918-S |
Mar 9 2010, 08:08 AM
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#27
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Hey nice rack! -Celette Group: Members Posts: 21,165 Joined: 30-December 02 From: Now in Superior WI Member No.: 43 Region Association: Northstar Region 
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A Celette would be slick for a tube chassis. You'd have all the suspension pickup points, enigne and transaxle mount locations and if you ever wrecked her you could replicate the chassis. Some cool photos in this thread! (IMG:style_emoticons/default/driving.gif) I totally agree with sir Andy though. Stiffening is a good idea but the 914 chassis is pretty good. 500 hp good though? (IMG:style_emoticons/default/idea.gif) (IMG:style_emoticons/default/confused24.gif)
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| Brett W |
Mar 9 2010, 09:52 AM
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#28
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Advanced Member Group: Members Posts: 2,859 Joined: 17-September 03 From: huntsville, al Member No.: 1,169 Region Association: None
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The 914 chassis is far from good. I think the factory chassis stiffness is on the order of 2500lbs/deg. That is really weak. The factory chassis is a noodle.
As for the tube chassis. I would use 1.5x.045 and 1.5x.065 tubing. No need to get really big. Sheridan's car is probably the best engineered solution. It was done by a professional race car engineer. If you are going to do it I would toss the factory rear suspension and come up with something different. Mount the engine, tranny and suspension to an independent cradle. Then you could fix the 914 problems. The problem isn't flex in the rear of the chassis though. It flexes in the middle. So you will not gain much buy changing the rear. Plus the rear is pretty light because it is all sheetmetal. |
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| plymouth37 |
Mar 9 2010, 10:41 AM
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#29
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Senior Member Group: Members Posts: 1,825 Joined: 24-May 05 From: Snoqualmie, WA Member No.: 4,138 Region Association: Pacific Northwest
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Thanks for the input guys, lots of great pics. I am going to try to remember my statics and mechanics of materials classes from when I was in engineering so I can calculate some loads. I figure if I use predominantly .065 wall tubing the entire rear structure should weigh around 50 pounds.
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| rick 918-S |
Mar 9 2010, 11:06 AM
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#30
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Hey nice rack! -Celette Group: Members Posts: 21,165 Joined: 30-December 02 From: Now in Superior WI Member No.: 43 Region Association: Northstar Region
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QUOTE(Brett W @ Mar 9 2010, 09:52 AM)  The 914 chassis is far from good. I think the factory chassis stiffness is on the order of 2500lbs/deg. That is really weak. The factory chassis is a noodle. As for the tube chassis. I would use 1.5x.045 and 1.5x.065 tubing. No need to get really big. Sheridan's car is probably the best engineered solution. It was done by a professional race car engineer. If you are going to do it I would toss the factory rear suspension and come up with something different. Mount the engine, tranny and suspension to an independent cradle. Then you could fix the 914 problems. The problem isn't flex in the rear of the chassis though. It flexes in the middle. So you will not gain much buy changing the rear. Plus the rear is pretty light because it is all sheetmetal. I agree the center of the chassis is where the 914 is lacking. I don't agree the entire chassis is bad. The rear and front sections are very nicely built for a street car. Stiffening where the shock towers crack in the engine bay side and a support for the inside suspension ear are always a good idea. There is alot of overkill being built into 914's. I think it's just because guys like to build stuff. BTW: I have zero chassis stiffening in my car. Yep. Zero. The rear of the chassis is just fine. Infact I removed the internal brace (boxed structure) just above the rear engine tin that crosses from tower to tower. I have in excess of 350 hp now with a very heavy engine. About equal to the weight of a big block chevy. If I Ax'ed on a regular basis or raced, I would rethink this. But for a occasional thrashing like Monument National Park or a trip to and from Mount Wilson these cars rock! It would be interesting to gauge what is happening to the chassis ahead of the rear firewall though... (IMG:style_emoticons/default/unsure.gif) Dana, Build it like you want it. We love your work. (IMG:style_emoticons/default/popcorn[1].gif) |
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| Rand |
Mar 9 2010, 11:25 AM
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#31
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Cross Member Group: Members Posts: 7,413 Joined: 8-February 05 From: OR Member No.: 3,573 Region Association: None |
Top of shock tower (bridging the hidden gap between frame rail and tower) and suspension ear are the two most important points. Much more is overkill and excess weight. IMO.
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| FourBlades |
Mar 9 2010, 11:35 AM
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#32
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From Wreck to Rockin Group: Members Posts: 2,056 Joined: 3-December 07 From: Brevard, FL Member No.: 8,414 Region Association: South East States
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QUOTE (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) Just build more stuff and take more pictures! (IMG:style_emoticons/default/biggrin.gif) |
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| URY914 |
Mar 9 2010, 11:45 AM
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#33
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I built the lightest 914 in the history of mankind. Group: Members Posts: 130,443 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
You build it and some will like it, some won't. Some will say it's too heavy, some say it's too light. Some will say it should be painted black, some say paint it white. You get the picture......
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| d914 |
Mar 9 2010, 11:47 AM
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#34
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Advanced Member Group: Members Posts: 2,350 Joined: 12-July 03 From: Atlanta, ga Member No.: 904 Region Association: South East States |
some one needs to design a full tube frame car...the buggy guys can build these things cheap.. Throw on a fiber glass body and youd have one hell of a DE car!!
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| plymouth37 |
Mar 9 2010, 11:49 AM
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#35
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Senior Member Group: Members Posts: 1,825 Joined: 24-May 05 From: Snoqualmie, WA Member No.: 4,138 Region Association: Pacific Northwest
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QUOTE(URY914 @ Mar 9 2010, 10:45 AM) You build it and some will like it, some won't. Some will say it's too heavy, some say it's too light. Some will say it should be painted black, some say paint it white. You get the picture...... Well as long as it weighs less than 75 pounds, doesn't bend, and looks sexy, I will be happy! |
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| URY914 |
Mar 9 2010, 12:50 PM
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#36
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I built the lightest 914 in the history of mankind. Group: Members Posts: 130,443 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
QUOTE(d914 @ Mar 9 2010, 10:47 AM) some one needs to design a full tube frame car...the buggy guys can build these things cheap.. Throw on a fiber glass body and youd have one hell of a DE car!! There are plenty full tube cars with 914 bodies on them. |
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| J P Stein |
Mar 9 2010, 01:42 PM
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#37
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Irrelevant old fart Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None |
Were I going to the trouble of building a tube frame, the first thing to go would be the Mac strut suspension & swing arms. Double A's all the way....just like a real racecar. (IMG:style_emoticons/default/biggrin.gif)
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| SirAndy |
Mar 9 2010, 02:15 PM
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#38
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Resident German Group: Admin Posts: 42,396 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(plymouth37 @ Mar 8 2010, 05:57 PM) So I have been playing with the idea of adding a couple more tubes to the back of the Anklebiter. Color me crazy, but i think the Anklebiter deserves a fully functional trunk. The car is going to be too nice to have a crappy "race car" subframe ... (IMG:style_emoticons/default/popcorn[1].gif) Andy |
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| plymouth37 |
Mar 9 2010, 10:10 PM
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#39
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Senior Member Group: Members Posts: 1,825 Joined: 24-May 05 From: Snoqualmie, WA Member No.: 4,138 Region Association: Pacific Northwest
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QUOTE(SirAndy @ Mar 9 2010, 01:15 PM) QUOTE(plymouth37 @ Mar 8 2010, 05:57 PM) So I have been playing with the idea of adding a couple more tubes to the back of the Anklebiter. Color me crazy, but i think the Anklebiter deserves a fully functional trunk. The car is going to be too nice to have a crappy "race car" subframe ... (IMG:style_emoticons/default/popcorn[1].gif) Andy I am willing to make a nice interior but I think an actual trunk that can hold things is entirely too practical for this project. (IMG:style_emoticons/default/biggrin.gif) I want this thing to be as close to a street legal race car as is possible. And never fear, I assure you it will be done right and not look crappy. |
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| jd74914 |
Mar 10 2010, 07:42 AM
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#40
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Its alive Group: Members Posts: 4,864 Joined: 16-February 04 From: CT Member No.: 1,659 Region Association: North East States |
Are you still in school? If you are you should grab a copy of SolidWorks and model what you are building. Then you can use the integrated FEA software to mess with tube sizes. Its quite easy to use (and there are some great tutorials about building tube frames in it on Youtube), and would really help you out with choosing tube size. (IMG:style_emoticons/default/smile.gif)
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