Today's formula 1 cars use torsion bar suspension. As you say the non-linearity is valuable. A rising rate spring is exactly what you want - far better than the linear spring plus bump rubber. Issigonis designed the "dry" mini with rising rate rubber cone suspension.
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that is not what he actually SAID..he said the suspension was non linear.
Citroën did it properly in 1955.
My '58 two ton Bentley had drum brakes. It could do a 'crash' stop from its top speed of 115 mph quite happily, although they would smoke quite a bit. Fronts were twin trailing shoe with a massive mechanical servo.
No they didn't. Simple trailing arm rear suspension - ok after a fashion for FWD, but useless for RWD. But even with their 'power' suspension, the car bucked like a bronco between engine pulling and braking - even with such a modest power engine.
Ah, thank you! I was wondering how you could make the torsion bar non-linear (I don't think you can, realistically), but of course it's simple to build it into the linkage in the way you describe.
Thanks, Arny.
Yes, thank you, I've responded to him.
Porsche did it in 1936
And near 50 years later, the Beetle finally got half decent rear suspension...
Controversial.
The Super Beetle was a true update but came in 1971 which was only 35 years later.
I can't think what car or development aligns with 1986 (1936+50) .
The New Beetle came 62 years later (1998) and was a completely different car being FWD.
FWD cars typically have relatively primitive rear suspensions and still handle pretty well because the rear suspension of a FWD car doesn't have a lot to do but keep the rear bumper from dragging on the pavement! ;-)
Not much difference between 35 and 50 at my age. ;-)
At least it was still a VW, unlike the Mini. ;-)
That's what many makers would have you belive as it keeps costs down. But the better handling FWD cars also have decent rear suspension.
Agreed. trailing arms and a rear beam is..vile. the original mini with its traling arms and IIRC a sort of wishbone arrangement was infinitely superior. Minis were almost impossible to get into a silly state, but the Morris 1100 was easy to get into a tail slapper on a trailing throttle. Vile. I think the second best FWD I have driven was the Punto. Oddly enough that cornered very predictably. Golfs were not bad either ISTR.
If my memory serves me right, all that era of BMC FWD cars have the same type of rear suspension. Front, too. The hydrolastic connection was more about comfort than handling, though.
In a former life I was an automotive engineer in a department that did development of future cars for one of the USA big 3.
Part of that job was suspension design and analysis. It is hard to effectively lie to me about steering and suspension design. ;-)
Right, but doing whatever you are doing right is far more important than which general setup you pick.
Even longitudinal leaf springs with a live axle done right can work well on reasonably smooth surfaces. High unsprung weight only matters on bad surfaces, which unfortunately seems to prevail these days.
For example people like to piss on FWD cars with simple trailing arms and a beam axle at the rear. However the beam axle is unsurpassed for keeping the wheels near vertical to the pavement which is very important for developing maximum cornering force. If the wheels are not powered, unsprung weight can be kept low. Get the trailing arm geometry right which is often done, and you have a nice vehicle - stable but still adequately nimble.
The gold standard is upper and lower control arms, but that soup gets pissed in at least as often as it is done right. ;-) Many compromises come when encroachments on the passengers and luggauge are to be avoided.
well that's as may be, - perhaps the weight transfer and compliances were just plain WRONG on the 1100.
I remember it being somewhat better on the Maxi I drove once briefly.
But it is always in the detail I (still have) a spitfire which was retrofitted with a massive anti-roll bar on the rear. That car with lowered stiffened fronts and an uprated front roll bar would do splendid
4 wheel drifts.An unmodified spitfire was - interesting - you had to anticipate the oversteer as te camber changed, steer into it, and once the suspension settled than hammer the loud pedal to get some approximation to fast cornering. Throwing it into a corner was simply asking for trouble.. but a smooth entry radially loading it up with some decent shocks on made it not the worse car I have ever driven...
Not my memory at all.
It's possible to make any car handle if you effectively stop the suspension moving - on a smooth road. Getting one which is comfortable and handles well on a rough one takes skill.
The Herald on which it was based was lethal.
I had two of em (heralds) and loved em, but you needed to take care.
They COULD be hustled along, but you needed a deft touch.
Turning circle was to die for.
Yes. However, that kind of perfection is not required for a longitudinal leaf springs with a live axle done right rear suspension to be effective.
They do loose traction on rough roads, badly.
That's why you need to be careful with how you do the trailing arms.
Its all about things like roll center. Pick that right and the not only will the wheels be parallel to each other, they will be perpendicular to the pavement. Hitting those two goals goes a long way towards good cornering. Most of the rest of the discussion then becomes about fore/aft balance of which a great deal relies on the front suspension.
Agreed.
Disagreed.
So can the two variants of the beam axle we've discussed. I've owned vehicles that handled well on even rough roads with unpowered beam axle/trailing arm rear suspensions.
Just because someone screws up a car, doesn't mean that every technology it embodies is inherently flawed.
yeah. You should try an XJS with a bent kingpin..
makes nonsense of a double wishbone
In the late 60s and early 70s, Ford Escorts with precisely that setup were unbeatable in rallying. All they added for the rally cars was a second parallel longitudinal link, and a Watts linkage for transverse location.
Gas dampers by Bilstein completed the setup.
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