I enjoy driving, especially when the car is performing as I wish. Making cars perform like this is what we do.
My own MG ZT-T 260 has been equipped with our VHS lowering spring kit manufactured by Eibach. It was very satisfying to confirm the suspension drop and to feel the greater agility provided by the revised front and rear spring rates. The geometry changes resulting from the lower ride height were also of the expected magnitude and direction (an increase in negative camber and toe in at the rear, with a small increase in negative camber and a negligible toe change at the front); a sign of the inherent robustness of suspension concept and manufacture. (You are probably aware that adjusting the ride height on an MGF or TF can cause rather wayward toe and camber results – I am planning to say a lot more about this next time). Presumably then, I adjusted the car to achieve the correct toe and camber?
Well, what is the ‘correct’ toe and camber? Having specified these values for the original production ZT 260 back at MG Rover, my starting point was clear. But plenty has changed since then, not least the (15 year newer and later generation) tyres and now the lowering springs fitted to the car. So, an experiment was in order. Aided by new rear axle cam bolts and copious quantities of anti-seize grease (with thanks to Chris at Retro Sports Cars Ltd), a series of tests were carried out to investigate the effects of camber and toe, front and rear. Using the ‘correct’ values as a start, each axle was subjected to large changes. The front axle does not include a camber adjust mechanism (although we do sell an Eibach strut camber adjust bolt suitable for the ZT 260) but the clearances in the two bolt connection between strut and hub does give quite a large camber difference; a care point when this connection is assembled. As driving assessments revealed the sensitivity of the car, ever smaller changes were made until the car worked as I desired, and a ‘nominal’ specification could be declared.
A few examples may help to explain what the driver can expect to feel during such tests:
Less toe in at the rear than nominal gives an open centre to the steering and an insecure feeling on making a direction change. More toe in at the rear than nominal gives a secure response to steering inputs, but the car can display a slight step/shuffle from the rear when crossing a bump during cornering.
Greater toe in than nominal at the front gives very direct steering response, with the car being very keen to change direction, albeit accompanied by significant feedback into the steering i.e. every road surface change is felt by the driver. This makes the car feel alive, but never really settled. Less toe in gives the opposite result.
So, a nominal toe and camber specification can now be declared for the car fitted with the VHS lowering spring kit.
The bad news? Well, the car is sensitive to small changes in both toe and camber.
The good news? Well, the car is sensitive to small changes in both toe and camber.
So, the really good news is that there are no unwanted kinematic or compliance issues which rob the car of accuracy and faithfulness – and the driver can enjoy the car with confidence.
Attention to detail has made the car perform as I wish. It is what we do at VHS Ltd.