Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Morgan SP1 - New Rear Suspension

The following CAD drawings show the rear suspension for the special project Morgan SP1, that was developed at the Works in Malvern.

They were ably assisted in the development by Spax - who helped with the tuning and development of the dampers, and Eibach who developed specific springs for this application.


There were various discussions before arriving at the solution and both me and my brother, who is an engineer, had discussions with several people but most notably with Martin Ogilvie - of Lotus F1 fame, who did not design the suspension in any way but gave some very practical input to us and also some advice on rising rate suspension design. The suspension is shown below in part of the SP1 chassis.


The suspension has been extensively tested running in a 3.7L Roadster, and also put on a rig at one of the Midland Universities, and everyone who has driven the mule is very happy with the suspension.

However SP1 has not run yet under its own power so that is the next item on the agenda, we do not anticipate any major issues and as the SP1 chassis is much stiffer than the normal trad chassis it might even work better. We shall see and I will report back in due course.

Cheers
Brian

If you were making a new chassis which is what I guess from your post, why did you not make one which would take independant suspension?

If you need someone to put 15,000 development miles onto SP1, I'd be happy to take her for a year Brian. As long as I can work out how to see who's behind me !!

Looking forward to the NEC Classic Show,

Cheers

It is not a completely new chassis, but a trad chassis with some space frame-ish additions. For various reasons, it was felt that the suspension developed should be retro-fittable to a Trad chassis.

Thanks for the offer Jeremy! It is intended to fit a rear view camera, though whether this will just be used for reversing maneuvers remains to be seen.

Cheers
Brian

An interesting solution with a fixed axle. It cannot be clearly seen from the images you posted but I presume that built into the design it allows sufficient rotational movement of the axle to not restrict its independent upward or downward travel. What I am getting at is at the points where the axle is secured to the cantilever arms these will be subject to rotational twisting in the vertical plane, unless I am missing something hear?

Interesting stuff. Thanks for sharing Brian.

I've long thought that a set up of this sort is "the next step".

There is nothing wrong with a well sorted rigid rear end, IRS is better but far more complex and expensiveness and in many respects would spoil the character of the MOG. I'll bet that with this rear and a Suplex front the Roadster rides and handles remarkably well!

I very much hope that MMC make this available as an option and adopt it as standard on the Roadster, rather than power steering... It could convince me to replace Aldermog....

I wonder if you are right about the cost. Morgan have to depend on buying parts made for other mass producers and right now I am struggling to think of another car maker who still uses a rigig driven rear axle. They all seem to have gone irs or front wheel drive or both. And of course Morgan cannot use any rigid axle . It has to be the right wheelbase.

Does anyone know the donor vehicle for the rear axle?

I was told it is a GMC product made for Holden in Australia. The "VN" Commodre had this axle, but NOT wth rear leaf springs, but as follows:

Rigid axle, Salisbury type. 5 link location with parallel short upper and long lower trailing arms and a Panhard rod between axle and under body. 16mm decoupled stabiliser bar, 30.2mm diameter dampers

So there must be versions available with attachment points for 5 link suspension. As this has to go under a "UTE" flatbed it won't be too tall, one hopes.

OK all our TMs in Australia, can you find out more>