Noses

[Adam43]

I was considering the change in the style of LM sportscars recently. Most of them tend to have a pronounced nose for the cockpit compared with the old Group C cars. Here is what I mean with the aid of the planetlemans.com site (check out the main GpC Spa race and Le Mans galleries for more examples).

New: Dome. It has a single-seater style section, with low down bodywork on either side.
Old: Proper Jag. A flat front. This is also very noticeable on the Sauber we have been talking about recently.

Now OK there is another change in these cars - from closed to open, but there is more to it than that. Consider the Bentley.

Is this just how cars developed? - if GpC had developed past the early nineties would they have these kind of fronts (was the 905 evo going that way)?

Notwithstanding that what has been the principle (if there is one) reason for the change? Obviously it has taken a decent redesign of some auxiliaries such as radiators. Or is it an improvement in chassis fabrication allowing for narrower monocoques? Or is there been some significant aero reason that has prompted the change. Or is it all down to a rule change that makes this the way forward.

[paul-collins]

My understanding is that it was aero - providing more air to the underside of the car to allow downforce generation.

The divide seems to be between the Audi R8R and R8.

[tblincoe]

well mulsanne will be able to answer this more in depth, but the development of the noses of the cars is based on the reduction of frontal area, as well as the management of air to the radiators and throught the car itself. by squashing the area around the footbox, frontal area is drastically reduced, and along with it so is drag.

transition to open top cars was for multiple reasons, the first of which was that the rules allowed the open top protos to have wider tyres than the closed top cars. although they carried slightly smaller restrictors, the open top cars had more grip as well as increased economy on their tyres, allowing the cars to double and triple stint their tyres.

the new rules could signal a return to closed top cars, but it remains to be seen what manufacturers will go to when they come back. Audi has been rumored to be developing both closed and open top cars so we will see what they come out with in 2005-2006

[Adam43]

Yes I think the open/closed choice is dictated by the tyres/restrictor and other rules. However the style of front end I'm describing existed on the Bentley too, so it isn't really dependent on the open/closed. Most (all?) open have gone this route.

Air going underneath the car. Well I tought this would be more to do with the splitter (and with the new rules they like their raised centre section like DTM cars).

I figured that it could be due to frontal area, but why 'suddenly' have teams decided that this is the way forward, when in the GpC days we saw more 'boxy' fronts? Surely it was possible to achieve something like today back then.

Was it just not obvious that the radiator could be moved and not comprimised so much?

[tblincoe]

its like i said before, its to reduce the frontal area of the car. squashing the area around the footbox reduces frontal area

[paul-collins]

Check out Mulsanne's Corner for the BMW LMR versus the Dome-reworked version. Does that address your perceptions?

[Dauntless]

Actually, I think the new noses are in response to FIA/LM's requirements for front crush structures.

[Tim Northcutt]

Originally posted by Dauntless
Actually, I think the new noses are in response to FIA/LM's requirements for front crush structures.

But if that were the case, the R&S MkIIIC would have a "Dome" nose, or a "Courage" type nose, etc...

It does not....it is the traditional look more like what you see on the Jag than on the "new" prototypes...

I'm sure that the R&S nose also has to do with the fact that it has a front radiator, whereas many cars now have the sidepod placement for the cooling elements....

[jhansen]

From what I've heard and read it revolves mostly around reducing frontal area and aero effect. That's a supremely scientific answer I know.

And I agree with you Tim, the MK3C has a nose like it does due to the placement of the radiator. The Robinson car ended up with a much different looking nose piece after moving the radiator.

[Dauntless]

Well, I certainly agree that aero management is important, and that a formula car-style nose is not the only way to meet crush structure requirements.

That having been said, most new designs conceptually are single seaters that have been widened to meet cockpit width rules. That makes it easier to add a single seater-style nose than it does on a traditional full width design like the R&S.

Designing for rear mounted rads opens up more opportunities to exploit the pointy nose, along with more favorable weight distribution. First, the nose splits the air to each side, which helps channel it into the coolers. Second, adding a chine or sharp edged top of the cooler inlet sets up a vortex along the top of the sidepods which, along with more drag, helps channel the air to the rear wing, increasing downforce.

[Tim Northcutt]

Originally posted by Dauntless
Well, I certainly agree that aero management is important, and that a formula car-style nose is not the only way to meet crush structure requirements.

That having been said, most new designs conceptually are single seaters that have been widened to meet cockpit width rules. That makes it easier to add a single seater-style nose than it does on a traditional full width design like the R&S.

Designing for rear mounted rads opens up more opportunities to exploit the pointy nose, along with more favorable weight distribution. First, the nose splits the air to each side, which helps channel it into the coolers. Second, adding a chine or sharp edged top of the cooler inlet sets up a vortex along the top of the sidepods which, along with more drag, helps channel the air to the rear wing, increasing downforce.

I agree with you 200% on that, Dauntless....

and the only prototypes that I can think of that are still available or competing with the "old style" frontal areas are the R&S, the Ferrari that Lavaggi was campaigning in FIA-SCC last year, and the Tampolli that Randaccio and Maddelena are running in the LMP2 class in the LMES.....

They are definitely the exceptions to the current design thinking....

[Adam43]

Its good to see that the frontal area approach is still important at Le Mans after all these years. It was the first main aero consideration in motorsport and one of he key considerations of Malcolm Sayer when designing Jaguar's Le Mans challengers of the '50s.

Paul those are interesting figures on Mulsannecorner. A huge increase in downforce and decrease in drag. It is the sort of thing that makes me think, so why didn't designers do that before?!

As frontal area has always been a consideration I was curious as to why only recently we have seen a move to this slender central nose. My original thought was along Dauntless's lines. They are just Single seaters with added parts. Which in some ways is both correct, but also selling them short. I'd rather say that maybe an improvement in the crash properties and manufacturing of forumla cars has provided a technology that has allowed Sporstcar manufacturers to do what they want.

One of the good things about Sportscars is the variety. Not everyone has gone down this route. However I wonder if we will see any cars designed from now on that don't...

[pirenzo]

Well, what about cooling too. With the sidepods on these cars so low, the bits infront of the intakes need to be a bit lower to allow air to pass into them better. IIRC one of the problems with the Panoz LMP07 was that it couldn't 'grab' enough cooling air because the side pods were so low and they couldn't make the bits that cover the front suspension any lower...