Torsion bars

[Matt49]

What I had drawn up is actually nothing like a sprint car torsion bar system but more like the way F1 does it. Using bell cranks where the center of the bell crank is on the torsion bar. To me, de-coupling the shock and spring is really something to think about. We talk on here quite a bit about how some of the pavement stuff is slowly adapted into dirt. I follow F1 closely as this is where the real "cheaters" are in terms of people looking to take advantages where the rules don't exactly define things perfectly. Very cat and mouse. Late model racing is getting more and more that way.

[JustAddDirt]

cantilever just on the left side?

Yes. That is my thought, lr only

[kiwi1955]

Looking back through some old threads and saw this. We will be assembling a cross torsion, 4 bar, open tube Super Saloon ( Kiwi Late Model) in the next couple of weeks. I got the chassis back from the powder coaters last week. This car is also set up to take a standard late model 4 bar coil over set up, closed tube, j bar etc. Our intention is to spend a day testing each set up and run with which ever is fastest. I will post some pics in a few weeks and would be interested to hear posters on 4m's thoughts.

[Krooser]

Keep us posted...

[hotshoe65s]

Matt.
It isn't necessarily a "torsion" bar, but Danny Drinan built a system that was pretty successful. He put it on a UMP mod in the late 2000's and was successful with it. Unfortunately it's been outlawed by about every sanctioning body.

http://www.dri-bar.com/

From my experience in NASCAR with anti-roll bars I don't see method of making it work very well in the rear of a modern day late model. With all that said, I could see it working on the front. You would need to have a lot of bar "slack" to allow it to roll on the RF, and then time it to engage at the correct point. Then you could clip the RF travel with the bar and run a softer rate RF spring.

[cjsracing]

Yes. That is my thought, lr only

Message SPark14 on here, he did this about years ago.

[over4T]

Late '80s when the rules were pretty basic and hard work & innovation could (occasionally) overcome the bucks I had a stock stub front clipped rule LM that we put a K member torsion bar setup from a California Highway Patrol Dodge on the front of an all fabricated chassis. Used rack & pinion steering from Ford Fairmont/Mercury Zephyrs that were $15 a pop at the local Pick 'n Pull. Rear was less exotic with stacked leafs and a pull bar.

Took about 2 years to figure out what we were doing as there was no one to bounce ideas off but eventually we got it to work pretty well and went to coilover mono leafs on the rear. Car was reaching it's potential and it got banned so I parked it for a couple years then reclipped it with a '76 Cutlass front end. It was never as good again and today, over 20 years from it's heyday, it still sits behind the barn. Maybe someday....

[kiwi1955]

Cross Torsion 4 bar set up

As previously mentioned, here are some images of my set up. Thoughts?

[Austin34471]

As previously mentioned, here are some images of my set up. Thoughts?

Looks cool.. why the open rearend? And what was the thought process period? Coil springs do a pretty good job of what they are designed to do. Definitely outside the box

[fastford]

i like the looks of that , is it one torsion bar running all the way through or are they split and work independently of each other?

[Austin34471]

i like the looks of that , is it one torsion bar running all the way through or are they split and work independently of each other?

Split. Basically using torsion bars for springs.. I would like to hear the creator's thoughts on advantages he was trying to explore. Can appreciate the design/fab work regardless

[Kromulous]

I have read that Torsion bars offer a lot better spring rate, and progressive-ness? I guess increasing and or decreasing thicknesses of the bar in various places can give the bar some vary cool effects in the realized spring rate.

[Matt49]

i like the looks of that , is it one torsion bar running all the way through or are they split and work independently of each other?

They're split. You can see the stops on the opposite ends of each bar.
If they were linked, it would be an anti-roll bar design. I've seen that in combination with the independent left and right bars on the front of some sprint cars.

[Austin34471]

I have read that Torsion bars offer a lot better spring rate, and progressive-ness? I guess increasing and or decreasing thicknesses of the bar in various places can give the bar some vary cool effects in the realized spring rate.

Not true unfortunately. Torsion bars are very linear. Making the bar different diameters in different spots would not make progressive or digressive. It would be like a stack spring with no lockout. You could make it act progressively at the wheel by doing some motion ration stuff with the torsion arm i guess.. or just use springs. lol

[JustAddDirt]

down under

As previously mentioned, here are some images of my set up. Thoughts?

Would love to see a pic of the entire car.
looks like you all do some really nice work (fabrication), and thinking outside the box.

Is the kind of car that has the transmission divorced from the motor, to help with rear weight %?