LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently Fri Oct 31, 2014 2:12 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 19 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: VW torsion bars
PostPosted: Thu Aug 18, 2011 8:08 am 
Offline
User avatar

Joined: Wed Mar 30, 2011 7:18 am
Posts: 457
Location: central Arkansas
Classic VWs used torsion bars front and rear. I wondered if they might be applicable to a midi.

As usual, "yes, but."

The VWs used solid round rear bars with splined ends, from 22 to 25 inches long depending on the model. The aftermarket supplies bars of various rates suitable for single-seat sandrails up to loaded buses.

Downside: the bars are splined on the ends, and each end is different. The outer ends are the trailing arm pivots, and can be purchased, but I didn't find a source for the inners. Of course you could weld bracketry directly to the bars.


The VW has four torsion bars in front, two on each side, one for each trailing arm. They're stacks of flat strips arranged into square bundles. You'd have to make up square sockets for them to fit into, not a big deal. Unfortunately, while I found umpty-dozen suppliers for rear bars, I couldn't find any front bars, not even used ones on eBay. VW bits haven't been junkyardable around here for a long time.

I'm keeping them in mind, though. I still have the stick of 4140 steel I bought to make the bars for the first car, but even though various people claimed they used the stuff without need for heat treating, I've had niggling doubts.


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Thu Aug 18, 2011 9:37 am 
Offline
User avatar

Joined: Thu Jul 17, 2008 9:11 am
Posts: 3070
Location: West Chicago,IL
The classis VW's used 2 front torsion bar "stacks" that are both constrained in the center of the tube. Take a look at some Formua Vee sites or dune buggy sites. These parts are still commonly available. http://dansperformanceparts.com/buggy/susp/buggysusp%20front.htmFor the front suspension, due to the reduced weight, FV's typically use only one of the stacks for springs. The center retension devise is redesigned to allow for adjustable ride wieght. The 2nd tube deletes the center retention device completely and instead of a stack, uses a steel rod with square blocks welded or brazed on the ends to fit the trailing arms. This 2nd "spring" is now reconfigured as the anti-sway bar.

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Check out my rotary build log: click here


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Thu Aug 18, 2011 9:58 am 
Offline
User avatar

Joined: Wed Mar 30, 2011 7:18 am
Posts: 457
Location: central Arkansas
Aha! The picture I found made it look like there were two short bars joined at the adjuster.

The link you posted shows the "front end adjusters" with the requisite square holes for $13 each and narrowed leaf sets for $100, stock width for $128.


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Thu Aug 18, 2011 7:29 pm 
Offline
User avatar

Joined: Fri Dec 17, 2010 1:24 pm
Posts: 368
Location: Gainesville, Mo.
You may have been looking at a front end setup for an off-road car. Many of them widen the front end by making longer torsion tubes with two anchor points in the center of each tube (four anchor points total), and each tube containing two half length leaf stacks.

_________________
Mike - Read my story at http://twinlakesseven.blogspot.com/


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Fri Aug 19, 2011 5:56 am 
Offline

Joined: Sat Apr 16, 2011 11:05 pm
Posts: 237
Location: Melbourne, Australia.
In my view, torsion bars have a few negatives, the main one being there is no simple way to change the spring rate once you have built it.

As you will need to have shock absorbers anyway, far easier to just wrap a coil spring around the shock.

Coils are light, compact, easy to change, and readily available in a variety of lengths ands stiffness.
Why do things the hard way ?


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Fri Aug 19, 2011 8:10 am 
Offline
User avatar

Joined: Thu Jul 17, 2008 9:11 am
Posts: 3070
Location: West Chicago,IL
Ahhhh but the VW torsion bars are diffferent. They are not made of a single bar/tube. They are composed of a stack of about 5-7 steel strips. The width and thicknesses can be changed or swapped out making an easily adjustable spring rate. If I want ~20% less spring weight, remove a strip. They do need to be individually greased up so that the individual strips can move against each other. The housing tube keeps the strip elements away from water and grime.

You are right about the simplicity of the coilovers. The problem is that the coilovers are expensive. Tradeoffs - tradeoffs - tradeoffs.

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Check out my rotary build log: click here


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Fri Aug 19, 2011 4:13 pm 
Offline
User avatar

Joined: Wed Mar 30, 2011 7:18 am
Posts: 457
Location: central Arkansas
Warpspeed wrote:
far easier to just wrap a coil spring around the shock.
...
Why do things the hard way ?


Coilovers have many packaging advantages. Unfortunately, the cost is higher than I like, unless I go for motorcycle take-off shocks from eBay.


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Fri Aug 19, 2011 5:34 pm 
Offline

Joined: Sat Apr 16, 2011 11:05 pm
Posts: 237
Location: Melbourne, Australia.
TRX wrote:
Coilovers have many packaging advantages. Unfortunately, the cost is higher than I like, unless I go for motorcycle take-off shocks from eBay.

That should work fine on a featherweight car, but my project will be a bit larger and a bit heavier than what most of you guys here are aiming for.
I am still at the initial mock up stage, but am using some old factory coil overs that originally came from Lotus and Jaguar to figure out my chassis pick up points, clearances, and geometry.
At a much later stage I will buy something really decent.
Shocks and tires are things where you mostly get what you pay for, and doing it really cheap may be false economy in the long run.


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Sat Nov 12, 2011 2:09 pm 
Offline

Joined: Sat May 17, 2008 10:55 pm
Posts: 167
Location: canada
rx7locost wrote:
Ahhhh but the VW torsion bars are diffferent. They are not made of a single bar/tube. They are composed of a stack of about 5-7 steel strips. The width and thicknesses can be changed or swapped out making an easily adjustable spring rate. If I want ~20% less spring weight, remove a strip. They do need to be individually greased up so that the individual strips can move against each other. The housing tube keeps the strip elements away from water and grime.


Does anyone want to save me a bunch of googling and put a image close up of this on this thread as a reference? This was all news to me and I thought I was pretty well informed.


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Sat Nov 12, 2011 2:21 pm 
Offline
User avatar

Joined: Mon Apr 12, 2010 5:40 pm
Posts: 1860
Location: san francisco bay area
The spline collars for the rear are on page 85.
http://www.denunzioracing.com/pdf/rearsusp.pdf

Quote:
Splined Collars
These splined collars, manufactured from allow steel, are used for special sway bar, spring plate, and
secondary bar installations. Available in a variety of sizes.
Description Part No.
Spring Plate Collar, 5.910” Long 44 Tooth Spline ...................... 701-5406
Spring Plate Collar, 7.810” Long 44 Tooth Spline ...................... 701-5407
Spring Plate Collar, 4.690” Long 44 Tooth Spline ...................... 701-5408
Spring Plate Collar, 3.500” Long 44 Tooth Spline ...................... 701-5409
Torsion Center Collar, 40 Tooth VW Spline ............................... 701-7010
Splined Collar, 3/4” 48 Tooth Spline .......................................... 701-9046
Splined Collar, 1” 48 Tooth Spline ............................................. 701-9047
Splined Collar, 1 1/4” 48 Tooth Spline ....................................... 701-9048
Splined Collar, 1 1/8” 48 Tooth Spline ....................................... 701-9049

_________________
"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Sat Nov 12, 2011 3:37 pm 
Offline
Automotive Encyclopedia
User avatar

Joined: Fri Dec 22, 2006 2:05 pm
Posts: 4787
iadr wrote:
rx7locost wrote:
Ahhhh but the VW torsion bars are diffferent. They are not made of a single bar/tube. They are composed of a stack of about 5-7 steel strips. The width and thicknesses can be changed or swapped out making an easily adjustable spring rate. If I want ~20% less spring weight, remove a strip. They do need to be individually greased up so that the individual strips can move against each other. The housing tube keeps the strip elements away from water and grime.


Does anyone want to save me a bunch of googling and put a image close up of this on this thread as a reference? This was all news to me and I thought I was pretty well informed.


Oct 9, 6:31 PM Post:
viewtopic.php?f=36&t=11384&start=45

King pin spindle beams have square receivers. Ball joint beams have an extra leaf centered on top and bottom. It takes some creativity to reduce the stack without welding. One could grind the leafs narrower between the ends and the center to reduce the rate and keep the full stack tight in the receivers. I'm going to try keeping the full rate and adjusting the center position to set the ride height at mid-travel.

_________________
My reverse commuter trike build log: viewtopic.php?t=11384
Fitting glass and weatherstripping: viewtopic.php?f=23&t=6451
Growing various fruit trees, berry bushes, and wine grapes in zone 7b.


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Sun Nov 13, 2011 7:36 am 
Offline
User avatar

Joined: Wed Nov 12, 2008 6:29 am
Posts: 3406
Warpspeed wrote:
In my view, torsion bars have a few negatives, the main one being there is no simple way to change the spring rate once you have built it.


Easy with VW flat springs, just slide your fixing fixture up and down the length of them as well as adding/subtracting leaves. Allows you quite a substantial range of fast adjustments and ride heights.


iadr wrote:
Does anyone want to save me a bunch of googling and put a image close up of this on this thread as a reference? This was all news to me and I thought I was pretty well informed.


http://lmgtfy.com/?q=Languid


Last edited by cheapracer on Sun Nov 13, 2011 10:59 am, edited 3 times in total.

Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Sun Nov 13, 2011 9:39 am 
Offline
We are Slotus!
User avatar

Joined: Tue Oct 06, 2009 9:29 am
Posts: 5185
Location: Tallahassee, FL (The Center of the Known Universe)
Yo, Cheapracer-
I fell for it, clicked the link... :rofl:

Good one!!!
:cheers:

_________________
JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Sun Nov 13, 2011 1:18 pm 
Offline
User avatar

Joined: Sat May 27, 2006 9:46 pm
Posts: 1094
Location: BC, Canada. eh?
Of course, if you could find an old Porsche 914 for a front-end donor, they have a very cool torsion bar design, with a pretty good front suspension already set up....

_________________
Scratch building, at continental-drift speed, a custom McSoreley-design framed, dual-Weber 45DCOE carburated, Zetec-engined, ridiculously fast money pit.

http://zetec7.webs.com/


Top
 Profile  
 
 Post subject: Re: VW torsion bars
PostPosted: Tue Nov 15, 2011 5:40 pm 
Offline
User avatar

Joined: Mon May 31, 2010 1:25 pm
Posts: 60
Location: Bijou basin
Sprint Cars and Midgets use Torsion Bars, based on the same principles, but are adjustable and changed out easily ...... http://www.world-sprintcar-guide.com/sp ... -bars.html
The bars can be bought @ differing spring rates for cheap ..... http://www.hoseheadsclassifieds.com/Cla ... ~57168.htm
and as far as coilovers go ..... http://www.hoseheadsclassifieds.com/Cla ... ~57771.htm
http://www.hoseheadsclassifieds.com/Cla ... ~58325.htm

Image

Image

_________________
Ahh; gitty up!


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 19 posts ]  Go to page 1, 2  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
POWERED_BY