how do torsion bars work?

[fty]

How do torsion bars work and if i wanted the tightest handling car should i go for 25mm or 30mm? Confused on how they actuallt work..thansk-chris

[adrial]

Thicker bar = stiffer springs.

It's basically a big metal bar that runs along the back of the car (from LR to RR).

I'm not sure what torsion bar matches up with 250# springs though...

[drew1]

They are a rod with one end fixed to the car & the other end fixed to the control arm. When the control arm pivots about the torsion bar center, it twists the bar. A larger diameter bar is harder to twist than a smaller when they are both the same lenght.

drew1

[fty]

Thanks so in other words I should get the 30mm for the best handling setup right? -thanks again-chris

[AFJuvat]

Getting the thickest bar is not necessarily the best idea. Thicker the bar - stiffer the ride.

Most sources I have read recommend 26mm as a good comprimise between street and track driving.

AFJuvat

[drew1]

Stiffest isn't nesesarily the best.

You want to keep the most rubber on the pavement. By stiffing you are limiting the up and down motion of wheels per load. Therefore you are limiting the camber change because of this.

Get too stiff and with the stock bushings give you're loosing grip with camber changes.

drew1

[eimkeith]

26mm more or less equals 250lbs up front.

[eimkeith]

wait, I may be wrong about that -
let's see = 25.5=180,30=350
naw, 26mm would be an ok match for 250#...

[rscupper]

I strongly suggest you go to your nearest Porsche suspension guru to talk. If you don't know of one, get thee to a race track and talk to people there who have already spent their money for their suspensions.

Unless you have lots of extra cash laying around, don't start buying pieces of suspension work that you will likely need to replace as you assemble YOUR suspension package.

I've been there - save, borrow, beg, whatever until you can put togehter your suspension at one time. You'll save a ton of money and be much happier with the results.

[fty]

Thansk guys...heres the idea I am lightening up the rear removing seats spare and panels and putting ina roll bar. so the rear will be light. I have 250lb springs up front and want to know what i need in the rear becuase the rear is loose as a goose and I get constant body roll which is annoying so what should i do? Should i equal the rear with the front? thansk again-chris

[drew1]

fty,

lots of body roll, most people would say bigger sway bars, but I,m not a fan of this. If you look at a say bar, it's hooked to the control arms and has mounts with bushings holding it to the body.
When the control arm on the leaning side of the body rises up, the sway bar tries to raise the control arm on the other side, unloading weight off that tire. A bigger sway bar would have less twist, having more of this effect.

I would try a set of 2" or 1 7/8" non adj round track coil over shocks with spr ings on the rear. I think you could get fixed up for less than $300 and changing the springs would be easier than changing torsion bars. This would allow you to experiment with different spring rates & ride heights without a whole lot of trouble.

drew1

[Pilot_951S]

fty,

You need to answer several questions.

What are you using for struts/shocks?

What torsion bars are currently in the car?

What sway bars are in the car?

What alignment settings do have currently?

What is your goal with these suspension ugrades?

[fty]

hey drew where can i get these coilovers?

I have eibach 250lb springs upfront and kyb struts around the car...stock sway bars front and back and stock torsion bars and alignment is stock...purpose Ii want a race ready suspension..i dont care how rough the ride is.....I give up making the car go faster the only way i see the car is worth anythng is turning into a crazy handling machine that is track ready-thanks -chris