How to bend torsion arms?

[Sides]

Sorry for resurrecting an old thread, but am curious on what the process and outcome was on bending the arms ???

I keep hearing about similar things being done to BJ Beetle arms, but there's never any specifics on "how"...

[buildabiggerboxer]

the beauty of arm wrestling is 'its just done' theres no messing about with anything else, you cant move the lower arm out because the t/bar is too short to redimple, unless you build a full on beam with extra width, i do this but still choose to bend the arms, or as above, and use coil overs, then the arms can go anywhere within the bearings limits, but i want to keep my car as near factory as i can, just to prove you dont have to play with all the 'must haves' to go quick.
just watch for the inner wheel or tyre fouling the shock towers on lock, the more i work with the t/beam, the more i think its better than the supers mac strut, its certainly a lot more versatile, easier to lower and add all the caster you like, none of which is easy on the strut supers without geometry problems.

[Sides]

Took a crack at doing this on my BJ race bug's top arms, and pretty happy with the result.

Posted a write-up with pics on my local VW forums - if anyone's interested the link is http://forums.aussieveedubbers.com/view ... tid=100412

[buildabiggerboxer]

good man, sorted, some times they get a bit near the shocker, depending were the bend is placed, what sort of tonnage did the press gauge get too? all you need to do now is get more weight on the front. i'm gonna test with the front bumper fitted back on, just to see if the extra wheel loading helps the lap time by making it bite better, i feel the bite going away as the fuel comes off..

[PlanB]

I ended up using spacers on the bottom beam (fabbed by a FV racer) to get the negative camber I was looking for.
Never found any specific info on torsion arm bending — to give me the confidence to try that route.

[Marc]

As I alluded to above, bending the control arms is about the crudist approach imaginable (short of bending the spindle). Bend the upper in and it gains length; bend the lower out and it gets effectively shorter. Disrupting the parallelogram like this means that something has to give when the suspension cycles. On a king-and-link front end, things just bind up, so unless you are dealing with a very sloppy front end the problem is obvious. A balljoint front end won't bind - instead, the spindle just turns to the side so that the suspension can move. INSTANT bump-steer effect for which there is no cure. Moving the entire (unmolested) control arm laterally requires more effort but IMO it's worth it.

[Steve Arndt]

There is a beam build thread I found on samba where the guy narrowed the bottom tube 1.5 inches and the top tube 2 inches. This gave him plenty of negative camber for road racing.

[Ol'fogasaurus]

Good post Marc! Steve, a better idea than bending things.

Remember, the difference between a WAG and a SWAG sometimes can only be seen via a microscope but the effects are often much larger than that. What is OK for the track often fails on the street as the beat-up street is often harder on things than the prepped track is and the track has help spaced around the course.

[JWP]

There is a beam build thread I found on samba where the guy narrowed the bottom tube 1.5 inches and the top tube 2 inches. This gave him plenty of negative camber for road racing.

I'm that guy with the beam

[Steve Arndt]

There is a beam build thread I found on samba where the guy narrowed the bottom tube 1.5 inches and the top tube 2 inches. This gave him plenty of negative camber for road racing.

I'm that guy with the beam

Excellent. Would you cross post your beam build to here?

[JWP]

It's actually a whole car build thread.
http://www.thesamba.com/vw/forum/viewto ... ht=dubbing

The good stuff starts at the bottom of page 1 and on into page 2.
I do need to fix on thing on the beam, what I call the upper right spring pack is dimpled about 3/16" too short
I am wrapping up the rear then I'll pull it back apart to do that. It's not really a problem per se, just that I'm OCD and want my camber adjusters to be pretty close to the same position on each side.
I would have loved to have covered the build in greater detail but my time is limited b/w working 50 hours a week, full time college schedule and a 3 month old baby.
If anyone has any questions by all means let me know. First and foremost if you want to build a beam like this start with some DOM. I expect that some day I will rebuild it using DOM, but again a lot of that is due to OCD tendencies.

If you go on further you can see some stuff I'm doing with the rear.

Once the front is fixed I will plumb the brakes, then move on to getting the engine in shape. If things go my way (hasn't happened yet) I will have it ready to drive around the block by December.

[buildabiggerboxer]

The arm bending works very well and has hundreds of users, i've even sent them out to Germany where according to feedback they work well in 24 hour endurance racing at Nurburgring, many race regs ban uprated and modified beams anyway, so they are not legal, also most folk cant do the builds we are fortunate enough to be able to, plus its great fun spanking highly modified and blinged up big buck builds with a car that looks stock , my new beam is full house and stretched 2", and already the remarks are coming in, " well you should be winning, it has special parts"... but i dont care, its all from folk who dont do anything to up their own game, here is the 1" wider beam earning its keep at brand hatch, https://sphotos-a-lhr.xx.fbcdn.net/hpho ... 8079_n.jpg
Something i noticed in your build may help you,, these days , for swing axle, the z bar and camber compensator are made redundant by uprated torsion bars, Jacking is eliminated by the larger bars, my extensive testing showed 25 0r 26mm to be the most effective for all round use including road use, over these sizes, up to 30mm works on the track, but i would not use these on the street, they are very harsh and need constant steering inputs, and can 'snap oversteer'. Try them.