Posted on 03/05/2008 5:29:58 PM PST by glock rocks
All good questions. I just am not sure that they would have taken this chance, I can’t figure that out since the inspection process is so stringent these days.
I do find this penalty interesting just to learn the aerodynamic issues here. NOT, because he beat Jr as some may think. :D
Here’s another opinion.
The Science of ...Missing Oil Tank Covers
Danny LaDue asks: Can you explain the location of a NASCAR oil tank reservoir and how the lack of one could improve aerodynamics?
Thanks for the question, Danny. I can–with a little help from Josh Browne, Chief Race Engineer at Red Bull Racing, who helped me disentangle a couple of things I heard on television.
First, the location. Unlike your car, the oil in a NASCAR car isn’t stored in the engine (which would be a wet sump system). NASCAR uses a dry sump system, in which oil is stored in an oil tank, and there’s a lot more oil than there is in your car. The oil tank is located behind the driver’s seat and is surrounded on the sides and top by sheet metal. The sheet metal plays an important role in minimizing heat radiating into the car, traps fumes from the hot oil, and serves as an additional firewall. This function is so important that NASCAR doesn’t allow the top of the tank to be attached using quick connect fasteners. The teams usually duct tape the lid on. The picture below shows the location of the oil tank with respect to the chassis. It doesn’t show the cover, which would sit on top of the tank.
So if the oil tank cover plays such an important role, why would you leave it loose, much less leave it off? The answer is aerodynamics. The air exerts forces on the car in different directions. We give different names to those forces depending on the direction in which they act. Drag is the force air creates along the length of the car. Air creates drag when it hits the front of the car, but it also creates drag when it gets inside the car because there is no way for it to get out. Drag always acts opposite the direction the car is trying to move, so you want to eliminate as much drag as possible.
Downforce and lift are the names we give the forces that push straight down or up on the car. Downforce pushes the tires harder into the track, while lift pulls up on the car. These two forces are in direct opposition to each other. Whichever one is bigger wins. You want to maximize downforce and minimize lift.
The oil tank is open to the bottom of the car. Air under the car creates lift. Even though you try to keep the splitter close to the ground, there is always some air that gets under the car. If the oil tank lid isn’t firmly tightened down, it creates a path for air to get out of the car, which reduces lift. Josh told me that there may also be a drag reduction–there was with the old car, but he wasn’t sure about the new one.
http://stockcarscience.com/blog/index.php/2008/03/05/oil_tank_covers
The writer states the lid is held on by Duct Tape but Everham and everyone else says there are screws and duct tape but then the two photos you linked yesterday show the guy lifting a unsecured cover. The mystery deepens...
The pics yesterday were from an 07 show car that DT stopped on the way to the airport to photograph for us just to show what the thing looks like. He did say the new Fusion 08 has a somehwat different cooler. I have pics of the inspectors looking at the cover so it did not come out of the car entirely. They are someones personal pics so I cannot post them here.
From what I understand these are supposed to be screwed down tight and then covered with tape so they should not come loose. At least I’ve never heard of this until the Nationwide cars at Daytona got dinged for it.
It occurred to me after looking at the photos that the cover can not come completely off because the hose goes through it.
Have you seen the latest issue of Sports Illustrated? Jr is on the cover along with the AMP car...
I tried to find it and buy it but they must think there are no Nascar fans here in this town. I do have the pic though. :D
impressive......thx
The tape is to keep the screws from backing out, not to hold the lid on.
Suppose that was for explanation only, as in what NOT to do.
I don’t think so. The photos I refereed to were the ones taken of a show car at a dealership and were just snapped on the run so to speak. WCG had a point that the car was not a COT but I don’t think this is a new rule?
There's always been rules pertaining to airflow up and through the car though, as in it's a no no. Seems I remember the crush panels being a bone of contention a few years back for the same reason.
Naw, that was Rachael Ray and her EVOO, and Tork never misses an episode.
I used to watch her too until I found out she was an Algore fan.
Should I apply for a patent that would involve a magnet closing mechanism?
That would not qualify as a mechanical closure (I.E screws), but may very well stick back down after the race so it would pass inspection! :)
I WAS talking about those pictures but I forgot what I said to you about them.
I think I blew out my operation. I went on a sneezing binge...
I sure hope you didn't, maybe you just strained it.
100
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.