M030 rear ride height

[frogisland]

For those with M030 (968 with rear helper springs) what rough ride height are you getting to the bottom of the arch?

My latest toy has complete M030 kit and it is bugging me that it rides quite high at the back, some c655mm to the bottom of the arch.

The problem is the dampers/springs. It has genuine M030 dampers which are the same length as standard non-M030 dampers (which incidentally sag when weight on them and thus reducing rear ride height) and correct barrel shaped helper springs. Problem is, these M030 dampers/springs dont particularly sag with weight on them making the car quite high. It does not matter how much you adjust the height on the spring plates or torsion bars, the M030 dampers and springs are dictating the overall height! They are adusted to quite a hard setting, maybe this makes a difference?

I have gone as far as adjusting the spring plates to play around - currently one is on full 'high' and the other side full 'low' and it makes no difference at all. The M030 cars have a different spring plate angle via the torsions (9 degrees for the M030 against 14 degrees for the non-M030 cars (taken from the flat part at the top of the torsion tube 'banana' arm that protrudes up into the rear arch for those that are interested) but i can't see much point, it just alters the point at which the torsion bars become 'active' - later in the barrel helper spring compression - and appears not to alter height due to the dampers/springs!

JP

[] p.s. there is a nice huge hint above to those who may ever consider reindexing there torsion bars.....makes life an awful lot easier combined with a digital spirit level [] (Rather than twisting so many splines on the inside and so many on the outside)

 

[Neil Haughey]

It should make some difference, I thought the rear helpers had a very low effective sping rate? i.e. most of the rear rate comes from the torsion bars.

Koni shocks do have a return spring effect although I always thought that was seperate from what ever the adjustment does to the valve.

 

[frogisland]

i thought that re the springs also. When they were off the car i could not compress them at all, the m030 dampers/springs have some degree of stiffness! It drives very well, and all appears to work as it should.

Left it as it is for now. Front is at 645, and this cannot go down much more, maybe 10mm....there is not much thread left on the collar.

I spoke to BigDave also today for him to measure his - he has a very low mileage m030 car and it appears his is very similar. Must be the way m030 is! (i had m030 on another car 6/7 years ago for a short time and had forgot what height it sits at)

Car with a standard damper on sat at about 640mm. Put the m030 damper/spring on and it sat at 655mm (after a drive). Dropped the car another 15/18mm on the torsion spring plates, standard damper back on and it sat about 625/623mm. Put the m030 back on and it was still sat at 655mm.

JP

 

[Big Dave]

Sounds like your having fun with setting up your motor JP....
Interesting observations....[][]
Now i/we know why the M030 cars always sit higher than a standard CS or Sport.

 

[chfs911]

Mine can run as low as 615mm but adjust up with spring plates to 625mm. M030.