So it's Le Mans week and the auto world just seems more abuzz this year than normal. It's awesome and I love early summer in France. Even when I'm here in the midwest.

Every article about Le Mans and the Toyota TS040 and the Porsche 919 lead to someone complaining about the look of the new fenders. They are rigid. They are ugly. At least compared to LMPs of the past, which aren't always 'pretty' but we respect them. Either way, lots of grief this year over fenders. Let's look into why.

First let's talk about the past. Prototypes were chisel shaped rockets with low front ends, arching fenders and angry profiles. The fenders ever since you were a kid also included extractors. Usually shark-gilled louvered extractors. Spend a moment on Memory Lane with the Ferrari 333sp.

Now these extractors serve a purpose: to relieve a bubble of high pressure that builds under the fender, reducing front end lift. The louvers serve two purposes. To smooth the flow of air coming out of them, hugging the body work behind and not disturbing the air rushing just above the fender top. Their second purpose was to look bad-ass.

Now, remember that the overall shape of a close-top prototype is pretty much a wing shape. Not an upside-down downforce inducing wing, but a real airplane wing. This shape in its native state wants to make lift anyway. We have the lovely Bentley to model for us this evening.


Great for airplanes. Lousy for race cars. now the really bad thing about this shape (especially closed-top prototype cars) susceptible to a condition called 'blow-over' when the front end of the car is partially lifted from the track (like after a bump, or sudden dip) and the rushing air lifts the car more, exposing more of the undercarriage to the wind, and more lift and more air... and you get very short flights in France.


...and sometimes in Georgia as well.

Now, when we combine this blow-over condition with large scoop-shaped wheel wells, the situation gets out of hand quickly. All of those louvers are presenting surface area and restriction to the wind making the blow-over from the front or from the side worse. There is a solution that is now present on all prototype cars in the series. The solution is the extractor sans the bad-ass shark gill louvers.


These large uninterrupted holes give the air scooped up into the fender's wheel wells more than enough space to escape and attempt to kill blow-over at its genesis.

But what does this have to do with ugly fenders? Why can't we have pretty, pointy fenders with large hole extractors? For our answer, let's again look to the past.


Lister in 2003 brought what may be one of the most thought provoking, but ugliest P-types in a very long time. Lister surmised that to avoid that Bernoulli wing-shape to the car, they would make their car force the air around to the side of the car instead of over the top. The 2003 Lister LMP attempted to be a snowplow of air.

The fronts of the fender were practically vertical. Revolutionary, but the idea didn't catch on. Except now it's back.


So remember the reason for the louvered extractor? No, not the bad-ass looks, the other part? To smooth the flow of air and streamline it to the body. Well, those louvers are history. Instead of a tight rush of air, you get an unregulated boiling tempest rushing out of the fender tops. Smashing it with more air rushing up a chisel shaped fender really won't help with drag or with downforce. Like Lister, Porsche and Toyota have chosen to straighten and blunt the fenders to again, plow the air to the sides and keep as much as possible away from the torrent coming from the new extractor holes. Until another solution to blow over is found, this is likely the profile of P-cars for the next several years.

Was it worth it? Style over substance? Sexy over sensible? I likely will never find out. Marc Gene may have an opinion.