1983 Lotus active suspension (Top Gear)

[grogee]

Apologies if this has been posted before, but it's great. Really 80s white males discussing "future" active suspension. Which we still haven't got. 

Also features two working Lotus Esprits on the same track. Bonus Woollarding at the start. 

 

[warch]

I think Landrover use an active suspension system for some of their models e.g. the Discovery 2. It does work very well when it's working. 

[grogee]

1 hour ago, warch said:

I think Landrover use an active suspension system for some of their models e.g. the Discovery 2. It does work very well when it's working. 

It's not fully active. I believe it stiffens anti roll bar(s) selectively. 

AFAIK we've not had a fully active suspension production car although the Xantia Activa comes close. Possibly also modern Mercs with ride height control but even they don't do 'zero roll' cornering. Lots of moderns with magnetic fluid dampers too - again not the same thing. 

Prove me wrong?

[warch]

I imagine an issue with zero roll cornering is that it promotes understeer/lack of feel. 
 

I have done a bit of fiddling around with the suspension on both cars and bikes and have usually found soft/compliant is better for cornering feel and possibly grip. 
 

I suppose the other issue is added weight/complexity and expense. Manufacturers are rarely rewarded for taking risks and quirky designs. 

[Asimo]

Fully active suspension was banned from formula one racing and that probably caused Lotus to immediately lose interest.

[grogee]

4 hours ago, warch said:

I imagine an issue with zero roll cornering is that it promotes understeer/lack of feel. 
 

I have done a bit of fiddling around with the suspension on both cars and bikes and have usually found soft/compliant is better for cornering feel and possibly grip. 
 

I suppose the other issue is added weight/complexity and expense. Manufacturers are rarely rewarded for taking risks and quirky designs. 

I'm with you on that, UK roads are not compatible with Civic Type-R iron suspension.

I get that it's complex and expensive but you'd expect a Koenigsegg/Bentley/McLaren to come out with a £750,000 glitzwagen to give it a try?

It just seems like a niche that hasn't been tapped and the motoring hacks would lap it up

[cort1977]

11 hours ago, grogee said:

It's not fully active. I believe it stiffens anti roll bar(s) selectively. 

AFAIK we've not had a fully active suspension production car although the Xantia Activa comes close. Possibly also modern Mercs with ride height control but even they don't do 'zero roll' cornering. Lots of moderns with magnetic fluid dampers too - again not the same thing. 

Prove me wrong?

Define 'fully active'.

Does it mean zero roll? Is that a good thing?

If you get to the limits of tyre traction with no cues to the driver that could be pretty dangerous.

[GR8 PL8 M8]

On 12/11/2022 at 10:35, grogee said:

Prove me wrong?

With pleasure - I owned a 1993 Toyota Soarer UZZ32 which had this system. Hydraulic struts just like in the video controlled by much computer wizardry. No pitch when accelerating/braking, and no body roll in the corners. Here's an image and a gif by way of demonstation:

On 12/11/2022 at 12:33, warch said:

I imagine an issue with zero roll cornering is that it promotes understeer/lack of feel. 

I have done a bit of fiddling around with the suspension on both cars and bikes and have usually found soft/compliant is better for cornering feel and possibly grip. 

I suppose the other issue is added weight/complexity and expense. Manufacturers are rarely rewarded for taking risks and quirky designs. 

There was a definite lack of feel in the corners, but I quite enjoyed the experience. It's ridiculous how comfortable that car was on uneven road surfaces, even after I'd had it significantly lowered.

Weight was indeed an issue, performance was muted somewhat. Lots of V8 noises but very little V8 go. I was always afraid to drive the car hard anyway in case I broke (or prematurely wore) something NLA, hard to fix, or expensive.

The car itself would have been very expensive when new, around the £70k mark if I recall correctly, at a time when a Testarossa was £66k. I paid a tiny fraction of that, depreciation is a wonderful thing!

22 hours ago, cort1977 said:

If you get to the limits of tyre traction with no cues to the driver that could be pretty dangerous.

Combined with the four wheel steering, every corner felt like controlled hydoplaning. Passengers hated it. I wouldn't want to try and drive one at it's limits that's for sure!

[Asimo]

On 12/11/2022 at 21:39, cort1977 said:

Define 'fully active

No springs or dampers between the wheel and the chassis.  
Suspension functions entirely performed via software control of actuators that both support the weight at each corner of the car and control suspension deflection.  

[PhilA]

The suspension looked great. If only they found a way to fix the turbo lag.

[Talbot]

On 11/12/2022 at 10:35 AM, grogee said:

It's not fully active. I believe it stiffens anti roll bar(s) selectively. 

It was active... one side drop-link was a hydraulic ram, meaning it didn't just "stiffen" the anti-roll bar, it actively forced one side down and the other up, making the vehicle sit (more) level in cornering.

The great thing about the system was that when off-road, it could then open the hydraulic valving on the ram and essentially disconnect the anti-roll bar from the suspension, which helps axle articulation. (anti-roll bars are a bad thing off-road)

It was a superb system.  Just a shame a lot of the pipes where steel, prone to rust and stupidly expensive.

[grogee]

17 hours ago, GR8 PL8 M8 said:

With pleasure - I owned a 1993 Toyota Soarer UZZ32 which had this system. Hydraulic struts just like in the video controlled by much computer wizardry. No pitch when accelerating/braking, and no body roll in the corners. Here's an image and a gif by way of demonstation:

There was a definite lack of feel in the corners, but I quite enjoyed the experience. It's ridiculous how comfortable that car was on uneven road surfaces, even after I'd had it significantly lowered.

Weight was indeed an issue, performance was muted somewhat. Lots of V8 noises but very little V8 go. I was always afraid to drive the car hard anyway in case I broke (or prematurely wore) something NLA, hard to fix, or expensive.

The car itself would have been very expensive when new, around the £70k mark if I recall correctly, at a time when a Testarossa was £66k. I paid a tiny fraction of that, depreciation is a wonderful thing!

Combined with the four wheel steering, every corner felt like controlled hydoplaning. Passengers hated it. I wouldn't want to try and drive one at it's limits that's for sure!

Thank you for enlightening me. I imagine that was very interesting to drive. Was it adjustable at all?

I would also have driven it with kid gloves in case something unobtainium broke and rendered the car undriveable.

I don't remember reading anything about that car at the time, and I was pretty 'up' on the mags in the 90s. Did it get much coverage? I imagine a Ferrari-priced Toyota was quite a hard sell then, though I realise why it was expensive. Thank goodness they're not trying to do the same thing now... oh.

[grogee]

36 minutes ago, Talbot said:

It was active... one side drop-link was a hydraulic ram, meaning it didn't just "stiffen" the anti-roll bar, it actively forced one side down and the other up, making the vehicle sit (more) level in cornering.

The great thing about the system was that when off-road, it could then open the hydraulic valving on the ram and essentially disconnect the anti-roll bar from the suspension, which helps axle articulation. (anti-roll bars are a bad thing off-road)

It was a superb system.  Just a shame a lot of the pipes where steel, prone to rust and stupidly expensive.

OK, it was active in that it was responsive to roll/steering inputs. 

I suppose what I was getting at was 'fully' active as in capable of zero or even negative roll. I don't remember many Discos leaning into a corner. 

To be fair to everyone on the thread, I suppose the term 'active' isn't strictly defined anywhere, AFAIK. 

I agree though, a cleverly designed system let down by usual piss-poor corrosion protection. LR has form there.