Hard vs Soft Suspensions

[era174]

...

[si]

It's true that cars that are designed for the Autobahn often have better suspensions.

BUT this day in age you cannot label a car's traits just for being "Japanese" or "European". 

Our Volvo has an expensively developed suspension system that works well, but the car has a lot of body roll. 

You must take each car individually.  An Acura TL may have a firm ride, where as a Toyota Avalon (older especially) may have a soft one.  A BMW 330i may have a firm ride, where as a VW Passat may have a soft one.

And remember that sportier, firmer, more ready suspensions are only a couple hundred dollars away in aftermarket parts.

[mdxtasy]

A car guru told me he prefers German and Swedish brands because they usually have SOLID suspensions. He argued Toyota, Lexus, and some Japanese brands have a little soft suspensions and might have problems in emergent situations.
 
For example, when driving and making an emergent stop at 100km/h, the front of those cars with soft suspensions might go more downward toward the ground while their rear might go more upward, resulting in longer stopping lengths or even improper stopping (their front touching the ground and spinning...).
 
I'm wondering how valid his arguments are and how those Asian brands (Toyota, Honda, Nissan, Subaru, Mazda, Hyundai, etc) stack up to those European cars with hard suspensions.

How valid is that argument?  Well, the statement "their front touching the ground and spinning..." comment made me laugh.  When you slam on the brakes, the 'car guru' is stating that some Japanese vehicles will cause the front of the vehicle to hit the ground?  Oh yeah....that's a good one.

Suspension setup cannot be generally applied to the vehicle's origin.  That's ignorant talking.  Like Robo says, take it on a case by case basis. 

Oh yeah...the front of the car hitting the ground...did it flip end over end too?   

[tpl]

All kinds of things go into suspension design:

spring rate
Shock absorber ( dampers really)  can have and usually does have different characteristics in jounce and rebound
anti sway bars
and importantly all the various flexible bushings that hold everything together

torsional stiffness of the body shell
rear end lateral stiffness of the suspension
live rear axle or independent
weight distribution f/r
and importantly the difference permitted by the mfr between loaded and unloaded mass and where it is distributed

weight of the wheels and tires
stiffness of the sidewalls, i.e. what sort of tires
permissible steering angles

front,rear or all wheel drive.

and..... what the mfr is aiming for in terms of handling and ride comfort

as for the original post.  Antidive can be designed in to cars and often is to varying extents

[safristi]

 .....If those metallic gel shocks used in top of the line Chevies(an electric current can instantly and
continuosly change the damping) were the be all and end all of constantly "perfect" suspensions they would be on every car.The design of the whole car ensures that suspensions are mated to the car and its purpose...i.e...somewhat softer for commuter cars all the way up to bone shaking in the Old RX7 twin Turbos,Vettes etc.......some light cars like Wingies Honda S2000 sports can achieve a balance of "cushy" riding with fine grip and lack of roll due to weight and money thrown at the whole set_up especially as the car is designed to be a TOP handler from the get go...the old Acuras were a particularly sweet handler for a Low/mid level price car...some designs do hit a "sweet spot" by Luck or careful design (I don't know).

[vroom124]

How does one become qualified to be a guru?  Is there a course somewhere? Is it from  Double Fisted Bent Elbow University?  Or the Cliff Claven School of Advanced Knowledge?

[safristi]

I'm ONE BRICK "short" of a LOAD!!!!

[ShadowDog]

He obviously has a bias toward European cars, and that's no different than the bias some people have for domestics, or asian-imports.  In the case of suspensions, there's far more you can do to resolve the personal issues one has with the handling of their car than, say, the lousy electrical systems of a Mercedes.

Heck, I want a stiffer suspension with better active handling?  Let's swap out the stabilizer bar, or use adjustable coil-over springs with more aggressively-valved shock absorbers.  Heck, one can have the suspension tuned dozens of ways to fit their needs and wants.  In my mind, there's far more non-adjustable aspects of a car to worry about when it comes off a dealership lot.

I tend to think that manufacturers aren't exactly building all cars with the most aggressively tuned suspension anyway.  Aside from ultra-performance GT cars, it's not like you can take just any car in stock form and go to the track.  Each will have traits that are better or worse than another on the highway; and I'm pretty sure that none will physically touch pavement in heavy braking.  That's only ever happened to me when toe-hooks scrape due to a parking lot incline being approached a little too quickly; otherwise, that's not exactly something to worry about at all.

[barrie1]

I think by now you must realize your Guru Pal is not all up on his gear as much as he thinks he is. Stick Around here and you can actually learn a lot about vehicles. There are many different reasons why some cars may dip more then others  but it all can be changed very easily depending on the need of the driver. 

[CSH]

Wouldnt we like this suspension in our cars: http://www.automobilemag.com/news/0410_bose/

[airbalancer]

or just get a Caddy with Magnetic Ride Control, unbelievable nice ride

[tpl]

various mfrs have built cars with computer controlled suspension like the Bose gear.  All so far have been too expensive/too unreliable.
As a software, sensors and actuator problem it is not THAT difficult but as the old saying goes:

Anyone can build a waterpump for a Rolls-Royce but it takes a REALLYGOOD engineer to build one for a Chevy.

[initial_D]

Range Rover, Porsche Cayenne, Audi Allroad have adjustable "air suspension", ride height can be altered at the push of a button or tuning a knob, or governed electronically via vehicle speed. Pretty neat! Ultra expensive. For the price of one of those fancy factory shocks alone, one can buy a pretty decent aftermarket set of coil-overs, and have them installed.

I think adjustable suspension makes sense to a car guy, softer and higher for the winter, firmer and lower for the summer, ultra stiff for track day. 

[random006]

THIS is hard suspension!:

[initial_D]

Stiffness can be measured using the Rockwell scale. 

[barrie1]

I can see Cadillac being the 1st car to have this system as they were the 1st car to ever have the Bose Sound system installed in them. GM actually worked with DR. Bose in designing the interior to help suit the Stereo system be incorporated in their cars. That has always been a nice stereo in any car.   

[tpl]

I think it is surface hardness measured on the Rockwell scale not stiffness IIRC

I was thinking of suspensions with no springs, no separate dampers but just computer controlled hydraulic rams. Suspensions that can make a car bank into corners like a motorcycle.

[UmroAyyar]

Either Cadillac or Lexus is going to get this system at first. All other premium brands, they got to toot their own horns.

[Turbo Bob]

Lotus developed fully active suspension in the mid-eighties IIRC, but it is expensive and heavy, never got fully developed.

http://www.autozine.org/technical_school/suspension/tech_suspension3.htm

"Until today I haven't seen any sign that car makers are going to put a fully active suspension into production. The main reasons, I guess, are likely to be cost, power consumption and reliability"