What happens with windows open at 100+ MPH? I have a non-aero tintop but people always say and everyone sees the 911's running double decker wings and even gurney flaps and wingtip spoilers that "work". I suspect that open windows with windownets that most people run has to effect the overall aerodynamics probably not in a good way. So what happens? People just accept this as a cost of doing business...its in the rules so no-one complains. Shouldn't we see more little tweeks like an A-piller spoiler to change flow separation or angled welded plates from b-piller to main hoop kinda Nascar looking or something to get the air to flow over the window openings? And do some cars have an advantage here because of window size or shape like say a giant BMW M3 window vs. a smaller Aston martin DB9 window opening? What about larger windownets that cut off more window surface area? I guess it all makes a difference. OEM's receed windshield wipers under the front cowling, eliminate rain gutters etc... and get more MPG at street speeds so it must matter.

 

That's allot to think about. My car is constrained more by its driver than by its lack of side windows

 

Listen to the noise - if there is less wind noise when the window is closed, then the car is more aerodynamically efficient with the window closed..

All closed cars are going to migrate to running with closed windows as the dominant racing series, ALMS/ACO/LMES (Le Mans) and FIA-GT are moving to compulsory cockpit air conditioning with cockpit air temperature monitoring. This will have a trickle down effect on other race car sries.

It is actually safer to run with the window closed, it stops 'stuff' entering the cockpit. In the event of an accident, its easy to break glass or whatever polycasrbonate material (Lexan for example) the window is made of, to get at the driver, if required.

Window nets exist because some race series demand that cars run with an open window. They are a nuisance, 'stuff' is not always caught by them, they get in the way and are visual 'noise'. They certainly make the car look more like a race car.

Many DE courses insist that you drive with all windows closed, for safety reasons, but this is not common in North America. As the practice trickles down in racing series, it will pervade DE days as well, eventually.

Its quite a good idea to tape up any sunroof and remove the fuse. I have had unfortunate experiences when the roof has 'moved' at speed, upsetting the boundary layer and causing early separation with drastic effect on downforce and sudden lack of stability.

People running big aero packages should be careful about changing their wing mirrors without checking the aero effect, it does make a difference.

Irritatingly, I believe that under some series regulations, one might run with a driver's side window in place yet still have to have a safety net. This is an anachronism. However, window nets are as much part of the legend as doors which are welded shut. If you observe the Supercup, for example, you will see that they do not run with safety nets. Nor do the Audi R10s or the Porsche Spyders, how come open cars don't have to have them? Logic dictates that there is more need for them in open cars than in the closed cars of LMGT1 and LMGT2.

Like it or not, for closed sports cars and GT class cars, safety nets are on their way out, there will be screams of protest, not least from some listers right here. Many people most in favour of open windows and safety nets also prefer open faced helmets. You would be surprised at how much stuff flies around inside the car when you get into a 'situation'. Keeping the window closed helps prevent items 'not required on voyage' from entering the car in the first place. open faced helmets can leave the wearer vulnerrable to flying objects.

Some race series even madate arm restraints - wow 'kinky' - very Vivienne Westwood! There must be some studies into the fetishistic aspects of motorsports. Imagine people's demand for safety nets being driven by obscure, 'not for family viewing' needs, rather than a 'responsible respect for safety issues'. The link between airbags and augmented mammaries does not 'bare' too close an examination either. The message is clear, 'get rid of the falsies babe if you are serious about racing'. Before anybody takes me to task for not taking safety issues seriously, let me say that some things are so serious that you can only joke about them.

R+C

 

Good points especially the open car vs closed car issues. They seem to not make sence. I have spun in the dirt and rocks on more than one occassion. Stuff gets everywhere and windows up would solve the problem. I have also been hit by a golfball sized rubber chunk at about 100mph in the head that somhow got around my windownet. It was quite startling. Windows would have solved that too. In the US. it seems we are stuck with open windows and windownets in tintops. What are the safety issues with arm restraints? They are kind of a mandated thing that nobody argues with and just does if they want to race.

 

Why arm restraints, never seen them outside of dungeons and some US race series? What happens if I need to dive out the passenger window in a hurry, its been known to happen.

R+C

 

The arm restraints I have used are coupled to the lap belts so come off with a single release which you have to do anyway to get out. The problem is with all the stuff you already have like HANS you just got 2 more things to trap you in the car. I am not an armrestraint or windownet fan. I think you could access or egress a car faster with a thin aluminium framed lexan window that you couls literally bend out of the way in an emergency yet provide not only better aero but higher safety.

 

[QUOTE=Nordschleife]
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All closed cars are going to migrate to running with closed windows as the dominant racing series, ALMS/ACO/LMES (Le Mans) and FIA-GT are moving to compulsory cockpit air conditioning with cockpit air temperature monitoring. This will have a trickle down effect on other race car srie...

I hope not... at least in amature racing. It is hard enough to keep the ABS and CEL gremlins at bay, if I need to add an AC tech and related spares to my must-do list, then that would suck... all the remaining tire dollars from my pocket.

 

I just dive through the window, it breaks. Safety workers just pull it out of the way. F1 has not yet found a need for arm restraints, though the dungeons in Budapest frequented by the drivers have a nice line in restraints, by all accounts. Do they stop you from adjusting the switches on the centre panel?

R+C

 

Seege
Given the way people will fit anything that is used on race cars, you can be sure that you will have to fit race grade aircon systems just for track days sooner than you fear!

R+C

 

In my case I think arm restraints are supposed to be used so your arm can't cross the winow opening. So in my case yes I can't reach my console. But also in my case I'm death gripping the steering wheel and holding on for dear life anyway. Once in the car everything is set it and forget it. As to future A/c in car I like the idea. On a hot day I think I could be more alert and comfortable and drive better. I am so heat intoerant that I stop racing June - september where the track temps can hit 120 and the air temps make it to 100. I have not found cool suits and air flow helmets to really do me much good.

 

Look at the console on the GT3s- you need to be able to reach it to use all sorts of switches, those restraints could be a pia

R+C

 

Interestingly, Nord Stern Region's DE event at Road America bucks the trend of both windows down, by mandating both windows up! Actually, you are allowed to have them open a couple of inches for air circulation when it's hot . This is the only track event I've been to that did this. Have to say, with the windows up there isn't the relentless wind noise and the car does feel more slippery.
Nick

 

I remember reading in article somewhere (a long time ago sorry) where an convertible (Miata I think) was tested in a wind tunnel and they found that "Roof up, windows down" created more drag than "roof down, windows up". From then on I always tried to run with my windows up (in a coupe).

ALso a Racecar Engineering article from about a year ago claimed that the best way to find 1s a lap in ANY reasonbly well sorted race car was through aero tuning. More reliable time found than engine, tyres or driver. It surprised me, but they gave a stack of examples from openwheelers to a hatchback.