TYRRELL's EXCITING CHALLENGER FOR THE NEW ERA

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by Dr Harvey Postlethwaite
Managing Director-Technical, Tyrrell Racing Organisation 

The new Formula 1 regulations have had a fundamental effect on the path we have taken in creating the Tyrrell 023 - our
challenger for what is surely going to be a new era in Grand Prix racing. 

Previously, technical regulations were changed only with two years notice, so the design of cars evolved quite slowly, which
meant there was a great deal of emphasis on detail change. Last year, the regulation changes came thick and fast and we had to
modify our 1994 cars while simultaneously beginning work on our 1995 model - the Tyrrell 023. Not only have we had to
work quickly, but the regulation changes themselves have pushed designers into a corner and the scope for innovation is tighter
than ever. 

From the design point of view the 1995 regulations present a refreshing challenge. Creating a racing car is a team effort
covering a host of often conflicting design areas. As the person directing that team, I've got to channel our resources into the
right areas. This year the balance of importance between those areas has shifted significantly. 

Back in 1989, aerodynamics were the top priority of the Tyrrell O18 design and some things were inevitably compromised in
order to perfect that key area of design. Now, six years later, on the 023 design there are many other areas which are just as
important as aerodynamics - not least the structural safety requirement introduced by the FIA's 1995 regulations. 

Stronger and safer...

The new structural standards are very demanding and the consequences of not meeting them would be dramatic - you don't get
to race! Every element of our new monocoque was crash-tested in isolation and the completed monocoque has passed the
official crash tests with flying colours. 

Tyrrell was the first British team to successfully complete all stages of the FIA crash test programme and we have taken the
safety aspects of the 023 design extremely seriously. We devised the novel approach of treating the entire radiator inlet pod as
an integral part of the monocoque, giving us the deepest possible structure to provide the greatest possible impact absorbtion. 

The FIA's safety regulations have been increasingly effective since the introduction of the current 'modern' regulations which
don't tell you how to design your car, but do tell you what safety criteria you must meet. We have seen huge strides forward in
the safety of Formula 1 cars - interrupted tragically by what happened at Imola. Nevertheless, the cars have got stronger and
safer. The 023 monocoques that we are making for the 1995 season are very strong indeed. They are also quite heavy. Since
the O18, monocoque tubs have put on between 10 and 15 kgs in weight. 

Searching for downforce...

Given the timescale, it has been very difficult to do other than build the best car we possibly can in the shortest possible time.
Fortunately, in the area of aerodynamics, we were able to handle much of the detail development work on the 022, here in the
UK. This enabled us to give Jean-Claude Migeot at Fondmetal Technologies a clear run at devising the aerodynamic package
for 023. However, although Jean-Claude's team at Fondmetal have been working exclusively on the 023 car for several
months, they quickly discovered that the nature of the aerodynamic forces you can generate around the 1995 car envelope
dictated by the FIA, is relatively restricted. 

The new aerodynamic regulations are very limiting in terms of pure generation of downforce. Over the last year - in general
terms - the regulation changes have cut the maximum available downforce by more than 30%. Put very simply, if you take a
fast corner as an example, in which a 1994 car generated sufficient downforce to go round at 3g, a 1995 car is going to corner
at 2.6g. 

Tyrrell has long been a leader in the area of aerodynamics. The team's trend-setting O19car of 1990, pioneered the
much-copied high nose and anhedral front wings. The 022 car's rear winglets, introduced at Monaco last year, were widely
imitiated by other teams whenever the Formula 1 circus went to a 'slow' circuit. 

This season, the need to exploit every last bit of airflow to generate downforce will see most cars - including our new 023 -
running with winglets from day one. Throughout 1995, Tyrrell intends to maintain its leading edge in aerodynamics. Over the
last eight years we have developed some very sophisticated techniques for setting up the car. We pioneered aero-mapping,
which is now a commonly used tool. But sophistication in aerodynamics won't pay such big dividends as it did before and that
brings us to other facets of design. 

A different challenge...

As a design team, we found the reduction in aerodynamic downforce, an intriguing challenge. It presents us with a more
interesting set of problems with the emphasis in different places. Starting with a clean sheet of paper there are a number of
parameters which clearly will be very important and finding grip in the more conventional way from the chassis and suspension,
will be a key factor in the seasons ahead. 

Here, in the search for mechanical grip, I think Tyrrell has a major plus. We spent a long time thinking about the kind of car we
were going to have to build for these regulations. Where the engine, driver and fuel were going to have to be located for the
'best' performance. What the wheelbase needed to be, and where the weight should be distributed. So, I hope we've got our
sums correct, our decisions right. As a curiosity for the technically minded the 1995 Formula 1 cars will have the lowest polar
moment of enertia of any Formula 1 cars ever built. 

Because the driver sits further back - the new regulations fix both the position of the steering wheel in relation to the car's front
wheels and dictate the size of the cockpit opening - drivers' feet are now well back from the front wheel center line. 

Less fuel aids the 'ideal' design...

The freeing of the fuel tank capacity regulations for 1995 is a boon to designers. Generally speaking, the smaller the fuel tank
the more flexible your approach can be to designing the car. That flexibility is especially welcome now that drivers must sit
further back which makes it more difficult to achieve the sort of weight distributions you want. A smaller fuel tank gives you
more scope to position the engine in the 'ideal' position. 

Personally, I like re-fuelling. It brings an extra dimension to each Grand Prix and seeing different team tactics being played out
during a race, adds quite a lot to the sport. The FIA has listened to team engineers and the re-fuelling rigs supplied to each
team for 1995 will incorporate a number of improvements to enhance safety. 

Air-power and six speeds...

The new regulations - particularly with the smaller fuel tank and moving the engine forwards - Ieads you naturally towards using
a longitudinal gearbox - and many teams will go that route. 

However, we decided to retain our six-speed transversal gearbox, knowing that we could incorporate the unit into our
aerodynamic package rather well. We have actually achieved some aerodynamic advantages compared to a longitudinal box.
We've put an extra 'drop' gear in the box in order to raise it, giving a cascade of gears to give us the best possible aerodynamic
shape under the rear of the car. 

The unique air-powered pneumatic gear selection system for the sequential box, which we introduced last year in conjunction
with Yamaha, is also retained. It incorporates further improvements developed over the winter and has been highly praised by
our drivers whilst testing during last month's sessions. 

Traction will be critical...

Something drivers are unlikely to be praising in 1995 is their cars' traction. With reduced downforce, traction will be a problem
and drivers are going to complain about 'lack of grip'. Consequently, the differential is going to be a very important area - both
the type of differential and the way you go about achieving traction. 

Getting the car off the corner is going to be the key, especially at some circuits where traction will be absolutely fundamental to
the overall performance - even with 650 rather than 750 bhp. 

In 1994, we ran with a novel type of differential that's now widely used - with a viscous type coupling. We will have to see if
the characteristics of this type of diff are suited to our 023 car. It may be that we will have to go another route and differential
development is an area we are concentrating on. Last year, we may have had an extra design engineer or two on wind-tunnel
work, now they are on differential work and suspension design. 

Suspension by innovation...

Designers never like to put the clock back, and we were reluctant to let the many performance benefits of computer controlled
active suspension pass into history. The desire to somehow retrieve those benefits has been accelerated by the realisation that
in 1995, keeping the wheels in contact with the ground will become critical. 

A great deal of time was devoted to conceiving, designing, engineering and producing our new 'Hydrolink' Suspension System
- developed with the assistance of Fondmetal Technologies. It will be quite important to us in terms of getting the very best out
of our 023 car. It's not something that's instantly worth a second a lap, but in the months ahead it will have highly positive
benefits - it will help us get the very best out of our chassis. 

At this time, the details of the system must remain secret. However, the key benefit is to be able to control both the roll and the
bump characteristics of the suspension - without compromising each other. 

We started with some carefully considered long-term goals for the Hydrolink System programme - and those are looking even
more encouraging now after track tests in Britain and Europe, than they did at the beginning. I think Tyrrell's future F1 cars
might look quite different because of this innovation. 

Formula 1 in the future...

What type of cars are these 1995 designs going to be ? Most teams are finding that the 3-litre cars are going very well. There's
a good balance of power-to-weight-to-downforce and I think that its probably a better ratio with 650 bhp than we had with
750 bhp. 

Despite the reduction in aerodynamic downforce, top speeds of these cars won't be higher - they only have 3-litre engines. In
very round terms, cars will be 15kph slower on the straight, and two seconds per lap slower - at the start of the season. These
cars are not going to be any easier on their tyres - they may actually be worse than last year's machines. 

Because of the new-for-1995 cars, I think Formula 1 will undergo a renaissance. They will provide better racing and the field
will close up even more. I consider that the overall effect will be to favour the driver in the three-way equation -
driver/chassis/engine. 

Looking at the broader picture, the restricting of computer-dependent high-tech and the tighter control of aerodynamics seem
to have a levelling effect across the Formula 1 field. Massive budgets are no longer a pre-requisite for success and that is
certainly a good thing. Now, rather than just spending money, designers have got to be creative and ingenious. 

l really believe that we are going to see some changes over the next years - things are gradually going to move around in
Formula 1. The established 'Top 4 plus the rest' situation is going to change. I sincerely believe that the 1995 regulations will
have played a significant role in this revival. 

Finally, a word of caution. If you are so minded, you can enhance the car's traction so easily by cheating, so I hope that in
1995 the FIA will be as tough as they said they were going to be in 1994... 


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Source: http://www.jtnet.ad.jp/WWW/MILDSEVEN/F1/