PeachParts Mercedes-Benz Forum - View Single Post

JimSmith · #42 12-05-2001, 05:45 PM

This is an awesome thread!

We are getting closer to the issues that distinguish good handling from not so good, or poor, handling in a vehicle.

German roads in the 50's, 60's, 70's and later were not all autobahn like strips of slightly curved, very smooth pavement. In fact, if you were in a city you likely often drove on cobblestone roads, with streetcar tracks crossing, and very little manuevering room between parked cars and other objects. In these circumstances a tight turning circle and a suspension system that kept the tires in contact with the road were considered high priorities. In the country, if you happened to be driving somewhere that did not have an autobahn exit nearby (which was most of the country, and most of Europe, at the time), you were going to drive on roads that were narrow, winding, with farm equipment, and other peculiar trucks that struggled to get up hills and around curves. You were also likely to want to go throught the Alps on some really challenging roads on the way to Italy and Yugoslavia (yeah, I know it is called something else now), both favorite German areas for vacationing in late July and early August. Here the need for brakes that did not fade, and a suspension that kept the tires in contact with the road (a concept Mercedes-Benz engineer Rudi Uhlenhaut coined to differentiate the Mercedes-Benz suspension design characteristics from those used on American and English luxury cars of the time, which would appear to be to smooth the road at the expense of control) was clearly a priority.

So when I say a W123 is a good handling car, it is because it is endowed with features that in its day were pretty exotic, like light weight, stamped steel semi-trailing arms, various aluminum bits and so on for low unsprung mass, four wheel independent suspension, gas filled shocks, anti-dive and anti-squat geometry, roll bars front and rear, four wheel disc brakes, radial tires, exceedingly stiff chassis, and so on. Together these features combine to provide a balance of handling characteristics that in the real world, driving down a mountain road with patched pavement and the occasional fallen rocks on the roadway and a slow moving truck just behind a curve you are taking at twice his speed, allow you to maintain control and safely respond to unexpected events. This makes driving a pleasure, in my experience.

Today you will find even cheap econoboxes with some or most of the hardware. They even seem to handle ok under most conditions, and in some cases good enough to encourage some drivers to push their limits. But under really trying conditions they typically give notice they have run out of margin too late. The integration of the hardware and the chassis to achieve the level of "performance" Mercedes achieved even with the W114/115 chassis is something these cookie cutter cars have yet to achieve.

That said, I think a W123 would have a difficult time on a track compared to most cars offered today, even the cheap econoboxes and pick-ups. But in real life situations it is no contest. I think that applies to trucks too, as I cannot imagine a truck, with a truck rear axle arrangement, keeping its tires on the pavement over bumps and curves going down a hill where the weight shifts forward even more. As for torsional stiffness, a ladder frame with a box screwed to the top just won't duplicate the W114/115, much less the W123 or W124 chassis. I am not a pick-up truck afficionado, but I have not heard of a unibody pick-up chassis and box. Could be the RAM has that but with an open box, hinged tailgate and screwed on, or pinned cap, it still won't come close to a unibody sedan like the W123.

I would find an unloaded pickup with a 40/60 weight distribution (front 40%, rear 60%) seriously impractical as loaded (for a V-10 powered machine, put a ton in the bed, for example) it would go to over 20/80, and that would be a true handling oddity. Even a 40/60 ratio unloaded would be a problem as the tendency would be to ignore the front wheel attempts to change the whole vehicle's direction when the steering wheel was turned on anything but smooth, dry pavement.

I think some of the tippiness of the the W123 puts some drivers off when the opportunity or need to push the car is presented. The tippiness is a consequence of the goal to provide a smooth ride under normal driving conditions. Once you start to push the car, it does not continue to roll over at the same rate - it takes a set and becomes very predictable. After you get to know this, the car can be pushed quite hard, and driven in a manner that is fun as well as comfortable and controlled.

Jim