Dallara on Multimatic’s Suspension Rig
Part l Of A Day Out In Norfolk

It was Martin Short’s idea: “Why don’t you come up to Thetford and see the Dallara on the rig at 'Dynamics' (Multimatic Technical Centre Europe), then go along to see the Moslers being built at East Dereham?”

Faced with another day in front of a keyboard, or a day playing with a prototype and, in turned out, the seven litre Mosler, it wasn’t a difficult decision. It turned out to be an absolutely fascinating day.

The man in charge of the suspension rig at Multimatic Europe’s base is Dave Williams, a wizard with a long history of very clever matters relating to suspension. For example, he was the brains behind the actively suspended F1 Lotus cars: say no more.

That's Dave Williams on the right, with two of the Rollcentre team - Pete and Chief.

So why are you here, Martin Short?

“You could test for a month of Sundays and not end up in the ballpark – and it’s also a lot cheaper to spend a day here, than it is to spend a day at the track. With track hire, tyres, engine use etc., it becomes very expensive. We have to go track testing, but this comes first. Dave has helped us on a range of cars over the last few years, and whenever we go, we end up with a better car afterwards.”

Dave Williams: “I can’t set up a car for the race track, but I can make the most of all the facets of the suspension set-up, ready to go testing.”

The Dallara sitting on the rig is chassis 006, the one damaged at the Spa 1000 Km – but the tub was unscathed. In our simple, non-technical, terms, the four wheels sit on four very clever, computer-controlled hydraulic ‘posts’, which when activated simulate the car on the track. Aerodynamic loads are applied front and back, by basically pulling down on the car with an appropriate force (below - you can just about spot a cable attached to a bracket, just above the diffuser) – while even the driver’s mass is simulated by some sacks of ballast in the driver’s seat.

“What we’re really doing is setting up the dampers to control the contact patch loads,” says Dave Williams.

That means a target of about 30 runs during the day, each lasting about ten seconds, with subtle changes to the damper valves between each run – or perhaps something more significant. Here the front dampers are being adjusted between runs - as stage two of the day's work commenced.

Most of the morning was spent on changes to the valving of the rear, Ohlins, dampers, Martin Short pointing out that “when a car is badly set up you can see the front and rear working against each other.” From his graphic description, it sounded as though a car could buck about horribly – but there was none of that with the Dallara.

“See how level it remains all the time? The front and back are really working together.”

Later in the day, some Dynamic Suspensions dampers were tried, and work was started on incorporating a third damper at the front.

The most spectacular part of each ‘run’ was watching the frequency of the oscillations build up: the Dallara initially bobbed up and down as if on the ocean (with the sidepods vibrating furiously), and as the frequency increased (it ranges from zero to 20,000Hz) it sat there – quietly humming to itself.

With the team having taken delivery of the two Dallaras quite late this year, there was no time for more than a couple of track tests before heading for Sebring in March: oddly, the team returned to the Sebring set-up in September at Spa, having confused itself with the front bump stops in the intervening period. Martin Short had explained at Spa that “the car was the best it had been all year, and we found ourself as competitive as we had been at Sebring.

"Most people missed it, but Joao sat behind eventual race winner Johnny Herbert for a whole bunch of laps, and then overtook him on the exit of Eau Rouge as it started to get damp..... unfortunately it was due to be Joao's in lap, so it never registered. We had spent most of the year fannying around with bumpstops and it transpired that they caused more problems than they were worth. Needless to say, we hadn't checked the bumpstops on the rig. A painful lesson for us.”

The man in conversation with Dave Williams (left) is 'Cushty', one of Martin Short's key technical men at his tight little Rollcentre organisation in Cambridgeshire.

Anyway, back to the Rollcentre car on the four post suspension rig. One advantage of a chassis like this one is that Gian Paolo Dallara and his team designed such a high quality product from the outset. What Dave Williams admits he can’t do is concern himself with things he can’t ‘see’. “I rely on lots of things being right about the car, even things I can’t see.”

He told the story of an Argentinian touring car that required his attentions (many years ago). “The car was hopelessly overdamped at the rear, but they’d obviously ‘nailed’ the car for a reason. They complained that their set-up was better than the arrangement I left them with, but it turned out that they’d nailed the rear because of the toe-steer that was taking place at the back – that was the fundamental problem that I couldn’t see.” The South Americans had got rid of the toe-steer – but it wasn’t the proper fix.

As the morning runs proceeded, it became apparent – thanks to Mr. Williams’ keen powers of observation - that something was changing. Of course he knew exactly what it was, because he’s seen it so many times: the tyre pressures had risen, which had subtly altered the readings he was receiving.

The huge quantity of date transmitted from laptop to projector to screen was mind-boggling for anyone not familiar with a procedure like this, but to get back to something easy to understand, the Dallara began the morning producing a reference number of 0.892, but by lunchtime, it was down to 0.345, with the ultimate target a figure of 0.1.

When Martin Short goes testing in the new year, he’ll be ‘simply’ looking at a more limited selection of variables, such as ride heights, wing settings and springs – knowing full well by then what damper settings he’d choose with which springs.

A signed photograph of Cristiano da Matta in a Champ car (on the wall of the office next to the rig) included a message from the Brazilian that summed up the value of work such we’d just seen: “Only Dynamics Dampers can do this”. Is he right?

Well, Multimatic’s Peter Studer adds the fact that “both Sebastien Bourdais and Nelson Piquet Jnr both used our Dynamic Suspensions dampers, and had their race cars set up by Dave Williams on our rig. All out of Thetford. Not bad, eh?”

Not bad at all, Peter: next stop for the Dallara(s) will be Sebring in March – the ultimate test of dampers and car set-up?