Dallara on Multimatic’s Suspension Rig
Part l Of A Day Out In Norfolk
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.
Dave Williams on the right, with two of the
Rollcentre team - Pete and Chief.
So why are you here,
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
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.”
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.
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.
level it remains all the time? The front and back are really working
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.
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.”
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.
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?
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?