morris62 wrote:new question for you johnathon, was the mgf front suspension a simular size to the minor or was it a lot bulkier?
The subframe and motor we used were from a Metro GTI rather than the MGF. However the whole lot would fit in just below the bulkhead crossmember. I'll try again to find the pics to help out
The wheelbase could be kept to the standard setting , this being preferable to modifying the bodywork. The track was obviously wider.
We never progressed passed an initial mock up just to see what was required and how the steering would be arranged. As I said it all loked very doable, but not commecially.
Hmm - there is this one - but it's still using the damper arm -although probably not as a 'damper'. http://www.jlhmorrisminors.co.uk/store/ ... roductId=2
I'm sure someone has done a MacPherson strut installation in the past.
That site's fairly picking up Andrew - you must have been working hard! Well done indeed!
I have found some pics of the cut up Metro GTI but none of the install .
Re geometry of the front setup, yes we start with the original settings but build in a huge range of adjustability for those who are searching for an ulitmate setting for their particular type of driving. The development at the moment is quite severe to the main bulkhead X member, and we might decide to remove and rebuild this with our own design.
The wishbones themselves are parallel to the ground and each other at rest.
What height roll centre are you using on your front suspension? Parallel upper and lower wishbones I believe will give a low roll centre, probably ground level if I remember correctly. With the live rear axle, the roll centre (with panhard rod or watts linkage) gives the roll centre at the centre height of the diff. These two together will give a skewed roll tending to lift an inside rear wheel and dip the outer front during cornering.
I came across all this when I originally ran very low minor front suspension which had the roll centre below ground level. When I built the new front end I made the geometry to give the roll centre about 5" above ground level (and faily well located throughout the travel/roll etc) which was the most I could achieve with the lower wishbone parallel to the ground. Transformed the car and reduced skewed roll massively. Skewed roll has only started to rear its head again (still using panhard rod on rear so higher roll centre than front) as the car is regularly pulling 1.4G in corners on sticky wide slicks!
bmcecosse wrote:Hmm - there is this one - but it's still using the damper arm -although probably not as a 'damper'. http://www.jlhmorrisminors.co.uk/store/ ... roductId=2
I'm sure someone has done a MacPherson strut installation in the past.
That site's fairly picking up Andrew - you must have been working hard! Well done indeed!
Martin B - very interesting - so, with the lower wishbone parallel to the ground - did you relocate the top damper mounts to change the roll centre position ?? Any chance of some pictures ?????
Also keen to see pics of the Watts - did you modify one from an SD1 by any chance ?
Hi Martin,
Yes I totally agree with your statement. We are however using as much of the std Minor as possible, so realise the short comings of a system built around these.
Changes to springs and roll bars can minimise the front end unsprung weight transfer. And as the set up will be unequal length parallel A arms we should achieve high lateral cornering loads and in turn better dynamic location of the wheel on poor surfaces and when cornering. We can also expect greater camber gain on bump as we will be setting up at 1-1'1/2 degrees negative camber and hopefully achieve around 1 degree of camber for each 1" of bump Most of all we are looking for grip and a good ride.
Avo have been very helpfull in the design and supply of the coil overs and load rates.As I say this is an exercise in producing a fast road car with ocassional track use rather than an out and out race car, that bit comes with the next project.
Last edited by jonathon on Sat Nov 22, 2008 6:28 pm, edited 1 time in total.
The current front end on my car uses Cortina uprights so is totally different.
When I ran the Minor suspension very low, I used Minor torsion bars and coil over shocks with 400 lb/in springs (to spread the loads out a bit but also could run softer shocks as the spring frequencies were different). The lower coil over mount on the Minor arm was above the 'Y' section where the arms widen to accept the lower trunion, basically as far out as I could go. I also had an extremely stiff anti roll bar (when the car was jacked up to one side, bouncing up and down on the wheel on the ground would also move the one off the ground). The very stiff anti roll bar counteracted the effects of the very low roll centre with the spring rates used due to the reduced suspension travel and the weight of the Fiat engine up front.
It was good on the track but also good on the road although obviously was pretty firm but still had reasonable compliance as the shocks did not need to be wound right up. On-track cornering would lift an inside front wheel slightly (only just off the ground, not miles in the air) and was pretty well balanced allowing full throttle cornering in 2nd, 3rd and 4th gears and controlled 4 wheel drifts in 4th (80 to 90 mph) on slicks. This was with 190 bhp at the wheels.
One slight problem was pad knock off on the front brakes which I think was down to the stub axle flexing.
I had also added stiffening bits to the shell including a brace between the chassis legs at the eyebolt locations. Rose jointed tie bars and negative camber lower arms (longer arms made to achieve the negative camber rather than packing out the eyebolts maintains the geometry better). The way it handled generally masked the inadequacies of the low roll centre OK. Understanding what you already have and making the most of it can often be better than cutting it all about and fitting a different system. I only replaced mine as I had a dissagreement with the armco at Combe due to driver error, but I had been pushing the car bloody hard up until then. This gave me the 'opertunity' to do the next step which was to move the engine back and correct the suspension shortcomings.
All the suspension mods I have done to mine over the years (whether with the Minor set up or the Cortina) have not only improved it for the track but have made it hugely more competant on the road. Despite the much larger output of the engine now, I still think the best mod on the car is the current front suspension geometry.
Really, I think the Minor needs an 'A' frame rear end with the pivot under the diff (similar to Carl Talbot's hillclimb Minor if I remember correctly). This is what mine could do with now, but I really can't be arsed!!
Martin
Last edited by MartinB on Sat Nov 22, 2008 9:20 pm, edited 2 times in total.
Sounds great - both of you - but have you ever tried re-locating the top damper J - or using a 'suspension arm' instead of the damper arm for the top location ? If the damper could be mounted lower and slightly inboard so the arm was horizontal or slightly downwards at rest - that would surely help ?? Maybe an easier answer would be special longer top trunnions which moved the arm upwards to a horizontal position and were designed to give a little negative camber at rest ?? Not sure if the damper has sufficient travel for all this - but I assume the arm can be removed and refitted on the splines to suit.
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