The other active suspension cars - Leyton House

[ffdave]

We have all seen pictures and videos of the Williams cars from 1992 and 93 but who knows about the Active Suspension system Adrian Newey and Nick Wirth were developing in 1989 with Leyton House on the CG891??

In recent interviews Newey has made comments about it but despite extensive searching i haven't been able to find any photos of it. Perhaps because it was only tested and never raced.

Neweys comments:

“I’d actually been working on active suspension at March/Leyton House, which was probably ambitious for a small team. It was slightly different from the Williams system. It was a platform control on the pushrod length that would have retained springs and dampers – not dissimilar to what McLaren did in ’93, which was on the damper platform. I don’t think that’s as good because your ride height goes all over the place”

“At Leyton House we worked on a platform control system, which is purely aimed at trying to control ride-height through speed and downforce variation as opposed to trying to deal with road inputs, and left conventional springs and dampers to deal with those. I believed that was the way forward. Small as we were, we were probably over-ambitious to start an active system. Ironically, it was the system that McLaren went on to use in 1993”

I know the test driver was Bruno Giacomelli and the chassis used for testing was CG891-01 but does anyone have more information about this system or photos of it??

[PlatinumZealot]

So it was more of an aero platform control system, than an outright suspension control system. The more comprehensive solution by Williams certainly paid dividends as it came to be.

[IVX8]

Educational question: After reading this thread I am curious what is the most prevalent control methodology in use ?

[tuj]

Moog valves.

[matt21]

There are alot of detailed description of the Williams system.
Has anybody more info on McLaren´s?

[riff_raff]

Moog valves.

High frequency digital Moog servo valves for sure! https://www.youtube.com/watch?v=7AME4v3qZkc

I recall watching an F1 race during that time, where they showed about 30 seconds of video from a camera attached to the side pod of Mansell's Williams looking forward at the front wing. It was fascinating to watch the gap between the front wing and the track surface remain perfectly consistent as the car went around the track.

[bdr529]

Here's Chris Economaki explaining the system used on the Lotus 99T from 1987

[Greg Locock]

[ It was fascinating to watch the gap between the front wing and the track surface remain perfectly consistent as the car went around the track.

As if there was no suspension at all?

[DaveW]

[ It was fascinating to watch the gap between the front wing and the track surface remain perfectly consistent as the car went around the track.

As if there was no suspension at all?

I don't think so, Greg. See here. Forward looking cameras were unusual at the time, but Nakajima had a contract to record a lap of several GP circuits. Many of them were eventually transferred to You Tube. Is possible that riff_raff might have been thinking of one of those.

[Greg Locock]

sorry it was just a lame joke.

[bdr529]

sorry it was just a lame joke.

That's not a lame joke, The "no suspension" idea has been tried before
http://bangshift.com/bangshiftapex/1980 ... lows-test/

[DaveW]

sorry it was just a lame joke.

Actually you made a very relevant point.

The aerodynamics of an F1 car were, and are, very ride height dependent - especially at the front wing. However, perhaps fortunately, the relationship is frequency dependent. The lowest vehicle mode that the suspension is required to control occurs typically at around 5 Hz. At that frequency the aerodynamics are pretty much decoupled from ride height changes, so if it was possible to control the ride accurately at frequencies below, say, 2 Hz, and allow the suspension to work at higher frequencies, then the suspension could be made (programmed) to cover both requirements.

I think there are two types of active suspension suspension systems that have been used in F1. One had actuators in parallel with springs, and the other had actuators in series with springs (& dampers). The Lotus system was a parallel design, whilst the WGP system was a series design. I suspect that the Leyton House system was also a series design, but perhaps not hydro-pneumatic.

There are many differences between the two types of suspension but, crucially, in neither case was the ride height constant.

It follows, I think, that riff-raff was the victim of an optical illusion (apologies). In the video referenced in my earlier post, the front wing appeared to be stable, but that was because the camera and the front wing were both attached to the same structure (the body). The movement of the wheel was, arguably, a reflection of the instantaneous ride height. The active suspension system (of either type) was able to keep the average ride height constant (or actually to a required value), but it also catered for rapid changes in ground clearance and allowed disturbances of the sprung & unsprung masses to be controlled more or less optimally.

The 1980 test, referenced by bdr529, caused WGP to design their own active suspension system.

[riff_raff]

I'm pretty sure the early 90's Williams F1 cars used a true electro-hydraulic system.

https://www.youtube.com/watch?v=7AME4v3qZkc

Take a look at this on-car video of Mansell's 1991 qualifying lap in an FW14. What is of interest is the relative movement of the front wing in relation to the track surface as the car goes thru corners and brakes. The perspective of the front wing roll/pitch relative to the track surface is not an optical illusion. Also note how the FW14 experiences no aerodynamic disturbance or downforce issues when it comes up behind the Ferrari at high speed and passes it.

https://www.youtube.com/watch?v=BIJa_nKyAOM

[bdr529]

riff_raff the second video you posted is a video game rFactor2, not the clip I think you wanted

[Tim.Wright]

Here is an old Scarbs description of the Williams system based on what looks like patent drawings:
http://scarbsf1.com/williams_active/Wil ... YSTEMS.htm