Whatever happened to 4 wheel steering ?

peasant

In the early 90's, 4 wheel steering was the latest and greatest in handling improvements.

Most notably the Honda Prelude, but there were some other cars around as well that offered this:



Are there any cars left these days that you can buy (new) with 4WS?
Anyone ever had a 4WS car ...what was it like?

Nissan doctor

It didn't actually help handling at all is mostly what happened to it.

The prelude was really the only mass produced car that had it operating directly with the front wheels, this made parking easier but high speed cornering very un-nerving as it always felt like the back end was stepping out.

Nissan were fond of it at the time too on the skyline, 300zx and some silvias. This system only operated above a certain speed and steering angle, again though, anyone who wanted to make their car handle properly removed it.

colm_mcm

Mitsubishi did something similar on the GTO

..... there were some 4ws pop up light celicas too, love the prelude that peasant has in the first post, great yokes. Never drove a 4ws one.

si_guru

Nissan doctor wrote: »

It didn't actually help handling at all is mostly what happened to it.

The prelude was really the only mass produced car that had it operating directly with the front wheels, this made parking easier but high speed cornering very un-nerving as it always felt like the back end was stepping out.

You are wrong a tad as the wheels turned into the turn for the first 1/2 steering wheel turn.. then in the opposing direction.

I guess cost killed it.

Plus any car with a positive camber and trailing rear arms has passive rear steering.

mondeo

That's a good question about the old 4WS systems, always wondered about whatever happened to it.

VolvoMan

Renault brought it back with the performance version of their current Laguna, but have since abandoned it I think.

colm_mcm

I think those preludes look rotten

Eric Cartman

isnt it an option on the f10 5 series ?

mondeo

colm_mcm wrote: »

I think those preludes look rotten

I think they look great:p. The replacement model though is slightly nicer looking.

Voodoomelon

Yup, its on the F01 7 series, reduced its turning circle by something like 30%.

colm_mcm

colm_mcm wrote: »

I think those preludes look rotten

They are most definitely different, lookswise they are no beauties.

Some presence on the road though, people just move over to facilitate you overtaking them in lots of cases. I had one for 6 months ish and 'twas as rough as a badgers arse to be fair to it but when polished up it looked decent enough at a glance. Lovely, lovely cars to drive, very good chassis, feel incredibly light despite being chunky enough weight wise.

I'll be on donedeal for the evening now :pac:

RandomAccess

Yep (as mentioned above) was advertised as a feature on the new Laguna a few years back on Irish TV.
(Guy lends his keys to his friend who takes it for a brief drive, then hops back in his Audi or BM and has to make two attempts on a corner that he got through just fine in the Laguna)

Camera showing it move
http://www.youtube.com/watch?v=NeNSXCLh0PM

Animation showing that it is an active system rather than passive
http://www.youtube.com/watch?v=-uRl9dH5ztY&feature=related

Harry Metcalfe was impressed

To prove this, Renault has invited evo to its proving ground near Paris to try a diesel-powered new Laguna equipped with the system. And the dynamic benchmark for this drive? A Porsche Boxster…

Driving both cars – and a standard Laguna as well – through a violent lane-change is illuminating. While the standard Laguna is hardly a dynamic benchmark, once fitted with Active Drive it transforms itself into one of the most agile front-drive cars I’ve ever driven.

http://www.evo.co.uk/news/evonews/210376/renault_steers_from_the_rear.html



A recreation of the demo with a Porsche boxster S
http://www.youtube.com/watch?NR=1&v=yBqKQoLU1ns

Very impressive, but its one of those things that never really catches on..

RandomAccess

Anyone remember the ad for 'Snow Motion'..
http://www.youtube.com/watch?v=UuXUhT5KUFg

I could end the winter tyre thread with one fell swoop...

mike65

Remember the passive rear wheel steering on the Citroen ZX, twas supposed to aid handling
at speed going round bends. The early 90s was also the era of the affordable mainstream family saloon 4WD then after a couple years most of the models were ended - Ford Sierra, Citroen BX, Vauxhall Cavalier etc.

Nissan doctor

si_guru wrote: »

You are wrong a tad as the wheels turned into the turn for the first 1/2 steering wheel turn.. then in the opposing direction.

I guess cost killed it.

Plus any car with a positive camber and trailing rear arms has passive rear steering.

I ment as in the system operates at all times when you turn the front wheels, On the Nissan atessa system, at standstill, the rear wheels don't move, only above 40kmh and a steering angle of greater then 45 degrees does it operate to help prevent oversteer...supposedly.

BrianD3

The Laguna can still be gotten with 4ws in the UK. As a hatch, coupe or estate.

The 4ws versions were on sale here for a while too but seem to have been dropped now. Here's a used one
http://www.carzone.ie/search/Renault/Laguna/GT-3.0-D/201117202183537/advert?channel=CARS

RandomAccess

BrianD3 wrote: »

The Laguna can still be gotten with 4ws in the UK. As a hatch, coupe or estate.

The 4ws versions were on sale here for a while too but seem to have been dropped now. Here's a used one
http://www.carzone.ie/search/Renault/Laguna/GT-3.0-D/201117202183537/advert?channel=CARS

Nice car, but looks like a blind man did the number plates. :cool:

€630 Road Tax, probably a UK car as the Irish site only gives the 2.0 Diesel option

CJhaughey

I had a Mazda MX6 GT in Oz in 92, it was a quick enough car back then.
160hp or so.
It was strange to park, at low speeds <40kph the rear wheels moved in the opposite direction to the fronts so the car had a very small turning circle.
At high speed they moved in the same direction which made for swift lane changes.

CiniO

Interesting idea.
I never heard about such thing as 4 wheels steering...

Maybe except from that video, but it's rather 2x2 (two steering wheels, and two drivers).

https://www.youtube.com/watch?v=5aEXIXRcPA8

Matt Simis

As it happens I started a thread bout it here:
http://www.bmw-driver.net/forum/showthread.php?t=30509
Source: http://e31wiki.org/wiki/Active_Rear_Axle_Kinematics

Its a standard feature on my Euro (well UK=Euro model) 850CSi and was an option (though rarely specified due to cost) on most 8 series models given the cars technical showcase positioning.


Did it work? Absolutely!

Minimizing the sideslip does not only improve safety in curves. During the development of AHK at BMW, people from BMW Motorsport GmbH (in 1993 renamed to BMW M GmbH) who were developing the 850CSi at that time, were given the opportunity to drive a test vehicle equipped with AHK on the Nürburgring Nordschleife circuit. The drivers had the feeling the car with AHK did not allow them to exactly hit the brake and acceleration points they were used to and complained they could not hit the proper racing line and apex in curves. Despite that and much to their surprise, the lap times of the test vehicle equipped with AHK were consistently noticeably faster. The reason is again with the sideslip angle: The car without AHK develops sideslip in a curve which is still present at the exit of the curve. The car with AHK on the other hand minimizes sideslip making it much more stable on the corner exit. This allowed the drivers to apply throttle much sooner and gaining higher speeds at the straights. Because of the performance edge AHK provided, BMW Motorsport GmbH decided to make AHK standard equipment on the 850CSi.

Nevertheless the 850CSi scored very well in tests which can be attributed mostly to AHK. In a series of tests performed in 1996 by the German Auto Motor und Sport Magazine the 850CSi put up a remarkable performance in the 36 meter (39 yard) slalom, only beaten by the Porsche 911 Carrera and Turbo and the Ferrari F350 sports cars. In the 110 meter (120 yard) moose test the 850CSi beat all other cars despite weighing over 500 kg (1100 lb) more than the other cars in the top 5.

The hydraulic system used on the E31 however is horrifically expensive to maintain if anything breaks. As in about EUR15k in parts. If it breaks most people leave it disabled and just use the passive rear steering on nearly all BMWs (which is something like 0.5 degrees).
My AHK works thankfully (did have to repair some pipework) and its great, it really makes the car feel much lighter than it is.