Dakar Design

[Tom]

Due to the '08 rally being cancelled Eurosport has been showing events from previous years in its timeslot. I've got totally hooked on the event and I was considering the implications of entering the event in the future (assuming the event is still running and I have appropriate finances).

For those who don't know the Dakar rally is an event which usually starts in Europe, crosses the Mediteranian sea by ferry or plane and continues through Morocco, across the Sahara desert and finishes in the town of Dakar on the Senegal coast, Africa.

There are 3 mayor catagories;
Bikes: These include ATVs (quads) and motorbikes. Now I've never ridden before (I'm itching to give motorcross a go) and I don't enjoy getting hurt so the bikes are pretty much out of the question.
Trucks: These rigid lorries usually carry spares for the teams car while competing in a race amongst themselves, they are big, heavy and expensive. I'd rather not race one across Africa.
Cars: These are the big boys of the race, ranging from specially built buggies, production vehicles, 2 and 4 wheel drives and the big marques running specially designed versions with some resemblance to their road cars. This is where I'd fit in.

I found the car regs here: http://www.fia.com/resources/documents/ ... rt_285.pdf

Anyway the reason I brought this topic up (besides a rare glimpse into the working of my mind) was to ask your advice on a few design related points.
As I watched numerous different vehicles I realised the advantage of this racing was a series with almost no rules. The cars must follow the above safety regs and be road legal, after that its up to the driver.

So what would be the perfect Dakar design? The rules do state that 4WD vehicles must have a higher minimum weight and must be front engine than 2WDs. Which would prove to be more of an advantage? I thought the answer would be obviouse until I discovered Schlesser (ex F1) has competed many events in his own 2WD car and won 2 consecutive events.
Would Diesel be able to beat Petrol? or is an alternative fuel the way to go? Is it better to buy a standard road car and develop it or start completely from scratch? I have no idea, with the range of surfaces they have to negotiate I don't think theres a right answer, some cars will be faster in the desert, some on the rocks, but there will be one design thats quick all over and thats the one I want to find.

[vyselegend]

Tom, I don't want to discourage you, but I read an article in "Auto Hebdo" magazine, about the cost of a Dakar for a private team, and it is a really big load of money involved!

They calculated the overall bill for the team "Pro System Racing" of Eric Vigouroux and Alexandre Winocq.

I've decided to share with you a synthesis of what I've read, as you might find it interesting. Here we go:

Subscription: 22 800€

-2 800€ + 10 000€ for each crew member (if you're on time, because if you're late it becomes 12 000€!)
According to the mag, it means between 22 800€ and 26 800€ before even talking about a car, suit, helmet and tools etc...

Tuning the car: 65 000€

This amount doesn't take in account the price of the original car or parts used. The estimation is from PSR's case, a competitor engaging a heavily modified Chevrolet Silverado pick-up.
-assembly and tuning cost: 55 000€
-a test session in Phoenix (USA): 10 000€

Assistance: 112 500€

-seven crew members in a T5 truck and a Nissan Patrol: 28 000€ +plus their own subscription bill: 59 500€
-rent of some space in another 3 T4 trucks (for food and water, spare wheel, replacement parts and tools): 25 000€

Fuel: 18 200€

We're still talking about the Silverado pick-up, with a 7.0 litres V8 mounted at the rear. It's consumption rate in the sand is 45L/100km!
(I guess this figure could be reduced quite a bit whith a less thirsty engine of course!)

Insurance: 3 800€

It seems nothing compared to the rest, but it is just covering the car and the crew members. Don't wait for some assistance in the desert with this price.

Vehicles paint & decals: 4 900€

Hum, thats more expensive than insuring people...
-700€ for the main car.
-3 000€ for the T5.
-1 200€ for the Patrol.

(I guess the cost of paint, stickers etc can be on the charge of the sponsors, but the mag doesn't mention it.)

Traveling by Plane: 6 500€

This is the most approximative figure, because it mainly depends of number of crew members, and their original location on the world map... Here it's still the Eric Vigouroux & Alexandre Winocq's team exemple, and they speak about economical class fly for everyone.

Lodging: 6 000€

The cost people's accomodation in Lisbon. (so another approximative price.)

Additional costs: 30 000€

-survival kits: 200€ per vehicle.
-road expenses: 2 000€
-protections and sponsor-decored suits for everyone: 9 000€
-visas: 1 350€
-rent and use of satelites linked cellular phones: 1 300€
-road maps: 600€
-cars rent in Portugal and Senegal: 500€
-buying images to the official photographers: 3 000€
+ countless sums of details like vaccinations, licences, etc...

So, here we are. TOTAL = 269 700€
And remember it doesn't include the original price of the car!

Also, sorry for the cynism, but it is now a fact that the whole Dakar can be cancelled in a moment, converting all this money in pure loss...

[Tom]

Thats the main point against the event but I never really start one of these ideas expecting them to come to light, I'm more interested in how I might go about making it happen just in case the oppertunity arises.

If I were to make a car capable of winning the Dakar what must it have and how would it work?

[checkered]

First off, didn't

bother to read the regulations yet - sorry. I'm not such a rally person, but if any event/vehicle of that category does garner my attention, it certainly is the Dakar variant. As I see it, you have an excellent chance of getting to work with desert vehicles ... defence and racing (sub)contractors overlap heavily and more often than not military types come looking for new ideas and engineering expertise from racing circles (be they academic or commercial). Taking very different types of companies as examples, Ricardo, Chenowth and Metalore are all involved in developing such systems and the specialist components to go with them. And there are many more (I don't know if any DARPA Grand Challenge teams have designed their vehicles from the ground up ...). Heck, even some NASCAR engineers have been involved. By this I don't mean to say you have to be involved in military vehicle development, just that there might be a great many people within your reach who have some very applicable experience in the field.

I don't quite know if the main part of Dakar is on roads or desert. The most impressive clips are always filmed from the dunes, but it might well be that the route ventures there only as much as to get that footage. Dune driving is certainly an art unto itself and requires a very alert mind, a steady hand and (hopefully) an experienced driver. The upwind sides of the banks (which can be huge) can be as hard as paved roads (I've been quite nervous in some very heavy vehicles driving right at the high edge of such banks ... fortunately the one that happened to collapse was relatively low and overturned the truck just once) while the downwind sides are treacherously soft. You don't want to drive down one at an angle. You don't want to turn heavily on a soft patch in general, the tyre can burrow in just like that and the next thing you know it's ripped off the wheel by the violent force transfer. The car can be left teetering at an almost impossible angle, causing all kinds of dilemmas and even engine problems later on. Read some off-roading forums, for example, those might shed some light on relevant engineering problems as well.

Once I was told a cool story about desert tyres by an elderly gentleman who had done a lot of desert driving in his time. Can't remember it exactly, nor can I corroborate it online, but the essence of it was that during either of the World Wars someone researched the perfect dimensions of a sand tyre and he ended up measuring camels' hoofs. It turned out to be the perfect reference and according to my "source", continues to be so to this day.

Where then, off the top of my head, would I begin planning for a desert car? I'd propably make it as light as possible to start with, with agile but steady enough dynamics. I'd put a lot of thought into the suspension, propably trying to couple body force transfers to traction i.e. exploring how the suspension could divide the forces as evenly (softly-softly) as possible when the tyres lose traction relative to the movement and/or transferring load away from a tyre that experiences forces from "unusual" directions i.e. when burrowing. Given typical desert conditions I'd explore the benefits of solar panels providing auxiliary power. The engine, whatever it is, should be adaptable to very hot and quite cold conditions equally. Preferrably any air intake should be such that even if you shovelled sand in it, it wouldn't end up inside - but there's a catch: You should be able to do this without a filter that needs to be cleared every fifteen minutes. Now, there's an aero challenge.

Well, don't think my ramblings are some sort of gospel about desert driving. There are people who actually do know their stuff and this I know only because I'm not one of them. Make notes, explore the issue further, make contacts. Some day the pieces of the puzzle might fall into place.

[fastback33]

We must be long lost family members, because i have been thinking along the same lines as you! I've always like the looks of those rc cars that they race on little dirt tracks and in the sand. In fact i think we could learn a lot from rc cars that can be carried over to road cars (but that's another thread for another day)

For example something like this. Of course chorten the cockpit a little bit to remove any unecessary room. And keep the front/rear track to a more conservative approach to what this car looks like. While still keeping it fenderless.




Seen the pictures of the 2008 Detroit Auto Show? I think that new Hummer HX, i think it is called, would be quite interesting seeing it on the dakar race.

[NumberTwo]

[DSRacing]

Hello everyone,

Been lurking around this site for a few years and read this thread regarding Dakar and desert racing. I thought I waould post some photos of Robby Gordon testing his Dakar H3 in preparation for the European Dakar later this year.