Rear coilovers on supers

[pantswagen]

ooh i almost forgot, i have a used pair of avo adjustable coil over shocks - eyes both ends, but me thinks 13mm eyes
-2 and a quarter inch springs, may fit an ally arm better than a steel turret
£100

[Wally]

Originally Posted by Superman

Yes, but what else did Porsche do besides just bolt that "shock" on there? What other modifications were made, in support, of the M030 option?

he does have a point (unfortunately) as the M030 option used that coil-over spring in addition to the torsion bars. Not instead of the torsion bars as we intend to do...

This option is the addition of the "shock/spring", not a replacement, you just add it to the suspension as a supplement; it's not a "coil-over" as you're thinking like the MBT and other set-ups out there.

My point is, if Porsche didn't remove the torsion bars then neither should you. The rear coil-over is "neat" and it's "pretty" but it's very very dangerous because the entire weight of the rear of the car rests on that one bolt (on either side). I would not feel comfortable driving a car that if one bolt was to break something like this would happen.

[Turbo Haraune2]

I have been driving mine with 944 arms and coilover, with single shear bolt on the bottom for several thousand miles now. mostly track drag and autocross.
No problems at all!

The 14mm bolt is probably the strongest on the whole car! its a 14-9 bolt, that is it wil hold 140kg pr square mm! that will give you a couple of tonn's to spare even if you take all the weight on one wheel.

I have no worries using it like this.

the pic's show what happen if you try to drill holes in the brakedrum to make it lighter...

and even if the bolt should break-your car wil only be lowered a bit.

[helowrench]

Why not just run the 924/944/968 bars?
cheap and easy to get. Relatively easy to install.
many options to choose from.
http://www.germanlook.com/Html/Tech/...Suspension.htm
and a full list of all at http://www.924.org/techsection/technical.htm (suspension section)


Rob

Originally Posted by Turbo Haraune2

I have been driving mine with 944 arms and coilover, with single shear bolt on the bottom for several thousand miles now. mostly track drag and autocross. No problems at all!

If there were a million cars that drove a million miles each, then I'd do it but I'd rather never ever take a chance with a safety issue. However, on a track car running single autocross you cut the risks down a lot.

[evilC]

The 030 upgrade was to add a coilspring to the rear damper in addition to the torsion bar to increase the wheel rate. I see that spring (anyone know the rate?) as a light helper spring on the rear of a front engined car. My concern is in discarding the torsion bar and fully relying on a coilover spring that needs to be around 500 lb/in. The forces in compression will then go into the mounts that were not designed for anything near the 1000lb loads that could be experienced.

evilC

I honestly never did any research on the 968 because it was my understanding that the 968 was nothing more than the latest model 951 and 952, as far as suspension and brakes are conerned. The 951 and/or 952 has this M030 option now that I remember, in fact, that webpage of the 968 M030 optional parts are all 944/951 part numbers sans the 964 (911) bushing.

This would work safely, as long as the torsion bar was not removed.

Does anyone know if this would work with the early 944 steel arm conversion? I have the entire rear from a 1985 944 for my 1303.

[aircool]

Does anybody know how the Remmele uni-ball kit gets around this problem? I believe that eliminates the torsion bars and puts the full weight of the car on the coil overs.

The German TUV certificate is very strict though so I cant imagine there being any chance of a failure just through a bolt shearing! anybody own this kit or seen one close up?

[Wally]

No, but 'we' (as in: not me, haha) found out that H&R has a claim on their site somewhere saying they did the research and found out the mounting points were strong enough!
HR is quite a respectable company...

[Simon]

Originally Posted by Wally

No, but 'we' (as in: not me, haha) found out that H&R has a claim on their site somewhere saying they did the research and found out the mounting points were strong enough!
HR is quite a respectable company...

H&R supplied the springs from the (Bilstein) cup suspension used in the Porsche 944 cups, which is how they ended up creating a tüv-approved coil-over set for the rear. They do still offer a complete coil-over set for the 944 with a tüv certificate stating that it is to be used without the torsion-bars.
http://www.h-r.com/bin/RSS-37-827.pdf

For the beetle however they only offer a coil-over for the front and non-coilover dampers for the rear, so they keep the torsion-bars in place, see: http://www.h-r.com/bin/29581.pdf

This basically means

• removing the torsion bars and running coil-overs on the rear of a beetle officially isn't legal in Germany
• The 944 aluminium trailing arm and the 12(?)mm bolt for mounting the damper is strong enough to handle the loads it is subjected to
• The upper damper mount on the beetles chassis could be the weak point (at least it hasn't ever been tüv approved to handle the loads from a coil-over)

[Wally]

Thanks for the excellent summery Simon!

It is weird though as the 944 top bolt (12mm) is the same size as the bug's...

Maybe nobody has Tüv'd it because of the high cost involved wrt being a 'low-cost' beetle...