Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Suplex

As sure as eggs is eggs, you'll have a better overall summer than we will Peter. I guarantee it.

...and our winter better than you summer too

What no ??

I am seriously considering this upgrade, as I had already been thinking about the Mulfab thrust race/spring conversion to replace my damper blades (05 4/4). I had already fitted AVO dampers which were a distinct improvement - the Bilsteins would replace the front AVOs of course (which I will sell).

The fitting instructions make particular note of the possibility of introducing steering shimmy if the damper blades are removed - would I be right in assuming this is no more likely than with the Mulfab kit, i.e. not very likely in a later car like mine?

I don't feel up to this work so will have it done by Beamish Morgan.

PJB has an '86 4/4 so I am sure he would be able to advise of his own and other people's experiences.

My understanding of the steering issue which I have experienced in my +8 is this. Originally Morgans had castor angle set to 3.5 to 4 degrees which was the optimum for narrow wheelbase cars, However this depends on the accuracy of building front frame and bolting it to the chassis, which is why I understand some cars get the issue and others do not. Also any play or wear in the rest of the steering set up, wrong toe in can exabaerate the issue. In wider bodied cars, roadsters and +8's the wheels are wider and also can effect this and these cars as I understand it can suffer from this more. Mulfab do offer a service to increase the castor angle to 5.5 to 6 degrees which involves replacing the king pin brackets as I understand it, alternatively there is a kit using a
Merc steering damper to stop any shimmer.

You may not get the issue anyway.

I have read the early cars had 4deg castor and the later cars 6deg - which should be the case with mine, hopefully.

http://www.amazon.co.uk/GA45-Magnetic-Ca...ey+caster+gauge from Sealey at around £30 ideal for checking caster and camber.
Indeed there will be barely a touch of shimmy with 6 degrees caster (Gemmer or R&P) and rest of steering in serviceable condition. But with 4 degrees caster and no damper very good chance it will kick in at around 55 mph.
Regards PJB.

Well the rain stopped long enough for me to pick up the car today. I can really only give first impressions because you adapt so quickly to the new feeling that unless you can swap backwards and forwards between two cars you really can't do an in depth comparison. Enough to say that the trip home of about 80 km encompassed a variety of road surfaces, traffic conditions and speeds.

I will start by saying that the front suspension was not too bad to start with. I had GAZ adjustable shocks fitted at the factory and after Borghi changed the springs for me under warranty, and after the new springs and king pin bushes etc had bedded in, the ride was acceptable, at the front anyway. Being a 2012 car it came with thrust races under the springs, and, in fact, they were used and those in the kit kept as spares.

The first thing I noticed, as others have reported, the steering was lighter, much lighter. It may be that the steering geometry was changed a little in the process but it is most likely due to the reduced load due to the lower spring being free and therefore not placing higher loads on the bearing.

The first section of Milan rough road I encountered gave me the impression that the front end was just gliding over the bumps, without the front end of the car bouncing up and down, followed by the thump as the rear end encountered the same bump. In fact the whole experience has highlighted the rigidity of the rear end. The first thing I am going to do it try reducing the damper (shock absorber) settings on the rear.

On the outskirts of Milan there is a section of roadwork and I encountered some really terrible bumps. The front end soaked up the shock as best it could but I suspect that they compressed the springs almost to their limit. The rear end hit them with a solid thump that made me thankful that my teeth are well attached.

After clearing the Milan traffic I was able to put on a bit speed and I noticed that the car corners with much less body roll. It has always worried me a little that the car seemed to have more body roll than it should for a sports car. I am happy to report that I quickly gained confidence and I am sure I was taking corners at a higher speed than previously. Any irregularities in the road surface did not make the car skip sideways clearly due to the fact that the front wheels now follow the road surface much better. I soon realised that I need to play a little with the rear tyre pressure and damper setting to get it to match the front better probably because the car is now cornering much flatter and feels better attached to the road. I am told that the lower rebound springs are relatively stiff in order to control body roll. I have to say that however strange it may seem the concept works.

One word of caution to those fitting the kit. Make sure that the adjustment of the springs is done exactly according to the guide and that the threaded spring seat and the locking ring are adjusted to the same position on both sides. I arrived home and decided to check that the stub axles were at the correct height above the lower plates after the trip and I noted that the adjustment differed from one side to the other. It turned out that the left hand side was adjusted correctly but the threaded rings on the right hand side were 4 mm too high. Whether this was due to inattention or misunderstanding on the part of the mechanic I can not say. Fortunately by turning the wheel to full lock I was able to adjust the rings from behind the wheel. It is not easy to do without removing the wheel but it is possible even without jacking up the car. The result of the maladjustment would have been that the car was lower on the right hand side, the rate riser spring would have taken up too soon, and that the car would have more initial body roll in a right hand corner than a left hand corner (at least until the car levelled). None of this was actually noticeable on the drive, after all 4 mm is not much.

In any case all in all a good result and I am now looking forward to the hinted at developments in a kit for the rear suspension.

Excellent write up. Thanks for posting.