building different spec monocoques

[pnagy]

why dont teams build different monocoques for each type of track? like building a Monaco/Hungary car thats different than indy. They already make different aero parts for each race so why not an entire car optimised for each track or each type of track?

[Carlos]

Welcome to the Forum pnagy.
Each chassis would have to be crash tested and homolgated by the FIA if the teams built different ones for diferent racetracks. It would also be a lot of development work. I think your considering each team might want something like a long wheelbase for fast courses with highspeed corners and a short wheelbase for really twisty, lowspeed tracks?

[Belatti]

Some years ago, one of the teams (I seem to remember it was McLaren) had a car with two wheelbase options. This was achieved with a spacer/deeper bellhousing between the engine and gearbox, and obviously a longer input shaft, and presumably slightly longer top rear bodywork, though in the period I'm thinking of I don't think even the gearbox, never mind the rear wheels, had any kind of aero package around them.

In this arrangement, the rear suspension was largely attached to the gearbox this was a kind of 'plug and play' situation and switching from one to the other was no huge problem.

If these modifications are permitted in 2007 technical regs, the influence of moving the rear wing back and having different bodywork, under tray, diffuser etc would undoubtedly have a huge effect on the aero design - from the tip of the nose to the trailing edge of the rear wing. It would be like having two cars (which is permitted during a season is't it?) and both versions would demand as much time in the wind tunnel as each other. I would think that even the best funded teams would find two wind tunnels and double the number of aerodynamicists an expense too far.

There again, maybe not!

[Belatti]

Sorry, the comment from below was written by phoenix in a racecar engineering forum

then Cameron Winton quoted this:

The way modern F1 cars are designed & built precludes this approach. They come up with a "design philosophy" very early (eg early in the previous season) dependent on what rule changes etc are coming in. This is usually derived from some very basic ideas. A good example is Renault looking at where the most places are gained (Off the start line) and the driver's style (Alonso needs a fundamentally understeering car). This gave a car with a rearward weight distribution.
looking at the past, people have looked at this and taken different aproaches. Lotus tried cars with adjustable everything (including wheelbase) in the mid seventies. I remember reading Gordon Murray talking about the early days of the Turbo Brabham-BMW's. He worked on getting a basic car right first time without even having adjustable aerofoils. He thought they would have their hands full working with the Turbo engines - It worked - Piquet won the champioship with the BT52

[pnagy]

thanks guys

[countersteer]

The Lola became the de facto spec chassis for the Champ Car World Series up until the mandated Panoz chassis. Although it was "standard", there was a variety of front and rear wishbones available from the factory that affectively moved the wheel centerline fore and aft in relation to the wishbone pivots. Using these parts, teams were able to, within limits, vary the wheelbase, CG, aero balance etc.

The same philosophy might be used today without a need to homologate the tub. I would assume the same would apply to spacing the rear suspension fore and aft as the crashworthiness of the tub would be unaffected. I think a spacer was how the backmarkers accomplished the change from V-10's to V-8's.

Just my $0.02

[RacingManiac]

btw, I think Ferrari in 1998 had the 2 wheelbase option for the F300...

[scarbs]

Here's a piece I wrote for a malaysian mag on the subject.....

"I would say that in terms of performance improvement for Hungary and Monaco, a shorter wheelbase would be quite low on the list of priorities and even lower on the scale of its return on investment.
A lot of people pointed at Ferraris poor showing in relation to McLaren as an issue of its long wheelbase hindering its cornering on the tight streets. I think the real problem was Ferraris Barcelona update which upsets the cars ability to put heat into its tyres. As Monaco was the first race where McLaren showed some dominance, too much was read into where Ferrari was losing at Monaco. As Ferrari also suffered at the subsequent tracks of Canada and Indy, Both tracks devoid of fast turns to load up and put heat into the tyres, their problem was clearly not a Monaco one off. As soon as Ferrari returned a conventional fast flowing tracks (Magny Cours\Silverstone) their tyres were working and the balance of pace was moved back in their favour…


If you think of the issues in creating a Monaco package…

Monaco is often regarded as a solely mechanical circuit, but aero is still important and not just in creating sufficient downforce. As the V8s are now down on power compared to the V10s, a lot of the more open sections of track are nearer flat out and lower drag is becoming important too. Aero still contributes a lot to the lap-time around the principality.

Its true the mechanical set up of the car is greater proportion of the lap time compared to any other track, as demonstrated by Red Bull and Williams pace last year. But the mechanical requirement is for grip, higher-softer suspension to get the tyres to work over the cambers and uneven road surface. Weight distribution matters too, despite everyone saying Ferrari have a disadvantage with this in their longer monocoque, the team have enough ballast to keep the weight bias forward, even though the layout inherently shifts weight backwards.
Wheelbase in terms of nimbleness is at most a tertiary factor, probably less. Getting around the tighter corners is as much a factor of steering angle and the traction control aided oversteer as wheelbase or track dimension.

To alter wheelbase you’d either have to shorten the monocoque or the pull back the front or rear suspension.

A shorter monocoque could be produced to create a shorter fuel cell or footwell. Currently the fuel cell area is larger than the bag tank they install into it. Thus it could be shortened in many cases without compromising Fuel capacity critical at Monaco (due to the slow pit lane, teams run less stops than usual). Shortening the footwell area is also possible as the drivers feet are already far behind the front wheel axis, this would have a greater effect in other areas; such as clearance for the front rockers\dampers\torsion bars which would be nearer the pedals and also the front splitter would have to be shorter and this compromises the amount of ballast teams could run.
Both solutions would require a new monocoque pattern, mould and then the manufacture of two or three monocoques, then a full set of impact testing. Especially when you consider teams only produce 5 or 6 monocoques a year now (Alonso only used one in 2006!). Clearly not a cheap solution.

While the latter solution is easier but which end of the suspension would you revise?
Pulling the rear suspension forwards would attractive as it would take out the angularity the teams force the driveshaft’s into. Plus weight would shift rearwards which is good for traction. Pulling the front suspension backwards has several issues, keeping the front wheel axis in front of the drivers feet should not be a problem as the driver already sits further back than demanded in the rules. The position of the steering rack is a greater problem, mounted to the front bulkhead the rack couldn’t be moved backwards and the extreme trailing back of the steering arms would create geometry and clearance problems (due to the greater steering lock required at Monaco).
Either solution would require new suspension members, these are expensive and time consuming to make patterns and moulds for, not to mention the aero impact these have on the car, their profiles would need to be developed to suit their new positions. Seeing as wishbone positioning and profiles have more to do with aero than sensible load paths and geometry, this would be a major undertaking.
Additionally both solutions (monocoque or suspension) would demand new aerodynamics. The importance of flow around the wheels has been highlighted this year by several Michelin teams finding their solutions simply don’t work with the different shape and squash of the Bridgestones. Having the front and or rear wheels in totally different places would demand a complete revision of the cars entire bodywork. As the teams are already unhappy having to create wing sets specific for this race, as well as Monza which is very much a one off track too. This eats up Tunnel time, that could be used to develop parts that would work at more tracks.

In summary for a small amount of extra nimbleness for one track the cost and complexity involved in creating a one off race car would be excessive for any team. The teams have already found more can be gained by developing their generic set up for most tracks rather than getting an extreme car for just one race."

[modbaraban]

Here's a piece I wrote for a malaysian mag on the subject.....

Thanks for this.