92 1.4 Torsion bar...

[nfbr]

I have got some 40mm lowering springs and would like to lower the rear of my car by 45mm.

Does anyone know how many notches i need to turn the torsion bar to lower my car by 45mm.

Thanks for any help guys!

Allan B.

 

[nfbr]

anyone?

 

[Chris_H]

once again this stupid idea of turning the thing a spline for 30mm etc is balls.

You take it out lift the arm till the height is about right and turn it till it goes in freely.

The real trick is knowing how much preload the cars gonna put on the bar so it doesnt bottom out.

 

[nfbr]

Well my mates brother is doing it. hes a mechanic for Renault Manchester, He just asked me if i could find out how many turns i need to lower it 45mm.

Im sure he knows what hes doing.

Just need to know how many spline things to turn it.

 

[Chris_H]

6504 million splines.

A renault mechanic, and your letting him touch your car.

Tell him a spline then. Might even be right.

 

[steve_rt]

chris, if you dont mind can you exapnd a bit on the knowing how much preload the cars gonna put on the bar? is it a constant, or will it change with the different spline positions?

 

[Chris_H]

righty torsion bars, the facts!

torsion bar, this is a bit of sprung steel (imagine a coil spring, stick it in a vice and uncoil it so its straight), put splines on the ends, 25 on the outer end and 24 (might not be 25/24 but its close to that, counted them years ago) on the inner end.

The way the bar works is the outer end is mounted into the mounting bracket, this end is fixed to the shell. The inner end is what actually attaches to the axle. The trailing arm going up and down (suspension travel) means that the torsion bar is trying to twist, this is what actually causes the springing.

Pre-load, now as the cars come from the factory the torsion bars are inserted to a certain height (renault use a tool that bolts in place of the damper at a certain length) this height is above the normal ride height of the car. This is why when changing dampers on a stock height car you need to jack up the trailing arm or leave the car on the ground to bolt it on.

The fact that this happens means the bar is under tension at all times. When you lower the car the preload can completely go. This is easy to see, when the cras lowered you can pull the torsion bar out with your fingers when its on a jack.

So when you lower the car the spring rate is lessend due to less pre load on the bar.

To keep the pre-load, eithe rget shocks specially made or dont lower it.

 

[Mousey]

this is true when i done mine i pulled the torsion bar out put a jack under the hub and lifted the jack while pushing in on the torsion bar hense one click.



Jon

 

[steve_rt]

and the preload therefore is essential to a good solid ride? is it dangerous to drive without it?

 

[Chris_H]

erm not really, lower is better it may be a tad softer but due to the lower centre of gravity etc it more than makes up for it.

 

[nfbr]

I just want my car to be lowered 45ish mm on the back

The guy who said he was gona do it pulled out. So im gona have to find another place to do it.

How much do you rekon a mechanic will charge to do it and fit the springs ?

 

[Ben H]

http://www.daz-uk.com/cliosport/guides/lowering-torsion-bar/http://www.daz-uk.com/cliosport/guides/lowering-torsion-bar/

There you go! Its for the 16V, so Im not certain it will apply to yours, but you get the idea!