Is there a Springsmith in the house? Front suspension question.

Hi guys!

OK, here's one for those who understand the beam front end better than me.

Planning on using an alloy front beam for my hillclimber.

My question is this....

To further lighten the front end, I'm considering cutting the leaf packs and securing with a second HT bolt inside the first one.

As I understand it, the leaves do provide a certain amount of shock absorbsion from side to side, however will the spring rate be affected by removing this middle section of spring from both beams?

What effect will it have on the performance comparibly to the full sprung front end besides lightening it considerably?

Thanks in advance.

Postie

Not sure what you're asking, but basicly if you shorten a torsion bar you will increase the spring rate. The front torsions are all that hold the trailing arms in the front end.

themadpostie wrote:Hi guys!
OK, here's one for those who understand the beam front end better than me.
Planning on using an alloy front beam for my hillclimber.
My question is this....
To further lighten the front end, I'm considering cutting the leaf packs and securing with a second HT bolt inside the first one.
As I understand it, the leaves do provide a certain amount of shock absorbsion from side to side, however will the spring rate be affected by removing this middle section of spring from both beams?

What effect will it have on the performance comparibly to the full sprung front end besides lightening it considerably?

Thanks in advance.

Postie

Took a few minutes to understand what you are talking about... Basically the torsion leaves go from side to side,
they are secured at the centre of each set - upper and lower...
and the suspension arms are attached at each end...

I don't think there is any reason to cut the leaves and secure each side set seperately...
I cannot see any advantage... the torsion bars are held at the centre and each end twist etc seperately...
one end twisting has NO effect on the other end....

I hope that answers Your questions..

cheers

LEE

http://community.webshots.com/user/68autobug

As has been said already, as you shorten the torsion leaves you will stiffen the suspension. The shorter you go the stifffer it will be. I would imagine that to get any real weight saving by doing this you would need to remove a hell of a lot of the torsion leaves. This would leave your suspension extremely rigid. You could then remove some of the leaves altogether to reintroduce some flex into the torsion leaves, but the trade off here would be strength of the torsion leaf pack being reduced.
I'd be looking for weight reductions elsewhere if it were me.

Cheers
Brendan

Thanks guys....

Thats what I needed to know to make a decision.

Increasing the spring rate is fine.... so thats perfect.

Even though the packs are secured, they will still have an effect on each end. Only way you could stop that is by not have them connected..... but thats getting into kinetic physics etc.....

As you've said, the idea is to lighten the car substantially....

Increased spring rate is fine and can be reduced marginally by removing one or possibly two of the leaves, lightening it further.

I can see why you'd think it wont be worth it, but you have to understand I'm trying to keep this car under 280kg WITH a steel front end..... this means I can get well under 270kg with the ideas I'm talking about above.

When you've got 190 methanol hp in the back, even a kg can make a HUGE difference.

Wouldnt on a road going beetle, but will here on a space frame chassis.....

Thanks again