Torsion bars

A spring is a spring, that's true. But where you go wrong is that different suspensions don't perform the same way. A slant 6 bar cranked up to the same ride height as a larger bar is storing the same amount of energy. That stored energy is equal to the weight of the car.

You think I got the physics wrong? Explain how you put more energy than the weight of the car into a torsion bar. You have no preload. This is why your coil spring example is a bad idea, because you fundamentally don't understand how the torsion bar suspension is working. You're not compressing a 20" tall spring into a 15" space and creating preload. All the torsion bars are the same length, you can't preload them that way. The diameter being different doesn't change the preload, it changes the ride height, and that is made up by different offsets on the hex.




Yes, if you have a 100 lb/in spring rate it takes 100 lbs to compress that spring 1". And if you have a 500 lb/in spring rate it takes a 500 lbs to compress that spring 1". Thats true. And the same is true in reverse.

The problem is, no matter which spring you use, the weight being removed is the same. It's the weight of the car that's being transferred back. You're thinking about this all wrong, you need to stop comparing equal heights and work with a fixed weight transfer, because that's not changing.

When you launch, the same amount of energy is being released regardless of which spring you use. The engine is doing the work, not the springs. So if you transfer 100 lbs, the car with 100 lb/in springs will rise 1", the car with 500 lb/in springs will rise .2", and the same exact 100 lbs of stored energy is released from the springs.



This is simply false for a torsion bar suspension. The stored energy is equal to the weight of the car on that corner. There is no pre-load. That's why you're getting this concept wrong, because this is not a coil suspension with preload.



Your height changes are correct. The problem is, you're comparing different amounts of weight. And that's NOT what's happening. If you're transferring 400 lbs, the 100 lb/in springs will rise 4", assuming you have that much suspension travel. The 500 lb/in springs will move .8". And in both cases, the stored energy that's been released is 400 lbs, despite the difference in height. Again, that's why drag racers use light springs, because the change in height creates more weight transfer. But the damn springs are releasing the same amount of energy. You can't lift more weight than what the car weighs.



You can't post the math "5 different ways". You can use 5 different examples, but in each case the math is exactly the same. The amount of rise is controlled by the rate of the spring, but the amount of weight being removed is the same in both cases, so there's no difference in stored energy release.

What you've posted is not 100% correct. What you've said about the spring rates and how they relate to height changes is correct. But everything you've said about stored energy is incorrect for a torsion bar suspension.

The big names you're referring too are great, but again, not torsion bar suspensions, and they don't agree with you. I get it, you understand what you have to do in order to get a better launch. But you don't understand WHY, and your explanation of what's happening shows this.

There is no difference in stored energy. The difference in height is because of the difference in spring rates, but the amount of energy released by the springs is the same, even if the height is different. You're looking at the suspension rise from completely the wrong perspective.



A torsion bar behaves EXACTLY like any other spring. Did you read what Dave Morgan wrote? You should, as he explains it better than I do. But I still have it correct. He uses drawings that make it clear.

I should find the book, copy the pages, scan them and post them up.

Of course, I don't know how to do all that stuff.