Julian Edgar, 50, has been writing about car modification and automotive technology for nearly 25 years. He has owned cars with two, three, four, five, six and eight cylinders; single turbo, twin turbo, supercharged, diesel and hybrid electric drivelines. He lists his transport interests as turbocharging, aerodynamics, suspension design and human-powered vehicles.
The Pitch Machine
In the story on suspension design that was published in AutoSpeed today, I said:
One standard model of car that I often see has a clear pitch problem: once you recognise its behaviour, you can see these cars porpoising along on all sorts of road surfaces! (No wonder I felt ill when I rode in the back of one.)
For those of you who live in Australia, that car is the current VE Commodore.
When you are driving in a lane adjacent to a VE Commodore, and especially when you can see it from the rear three-quarters perspective, carefully watch its body behaviour.
What you will see is dramatic pitching over bumps.
Rather than the car as a whole moving up and downwards on its suspension as the bump is met and absorbed, the back rises and falls, and the front rises and falls – and when the back is up, the front is down, and when the back is down, the front is up!
It is fascinating watching a VE pitch, and then watch another car pass over just the same bump and barely pitch at all.
I reckon that Holden suspension designers have completely forgotten this aspect of suspension design – if of course they even knew of it in the first place.
