and I agree with dearborn's answer, even with 4 posts
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| Initial D World - Discussion Board / Forums > Technical Discussion > Weight vs Aero |
| Posted by: MetalMan777 Nov 15 2010, 10:10 PM |
| I haven't done nearly enough experimentation, and I know theres no definitive answer for every track out there, but generally speaking, which is more important? Obviously both count, but most lemons cars I've seen have foregone glass everywhere but the front, and ditched hatches out back. In lemons, I'm sure the weight reduction matters more than aerodynamics. Considering the clusterf**k that is a a lemons race, you never see huge numbers on the speedo, so weight reduction counts for a lot. Lemons isn't the only $500 race series out there, though. UsedCarRacing, for example, only had 13 cars, on the fastest track in America (Nelson Ledges, I think they use average speed to determine that), and the average speed over 24 hours was 71mph. That means the front car (I worked in the pits for them, fun time) spent a fair bit of time over 100. At those speeds, aero makes a difference. Is it worth it, then to leave in the windows, or replace them with polycarbonate, and not remove the rear hatch? Is it worth it, as well, to not reduce all weight possible in an attempt to maintain chassis rigidity? How about simple aero mods, like an underfloor panel made of flat plastic bolted on with a crude rear diffuser? In NASCAR, taping up the front radiator intake makes a difference, and they occasionally come into the pits just to add or remove pieces of tape. I'm going to spend some time testing this out on my 6er when the spring hits, I'm going to take it to the track, and use it as a testbed. I just want to get some ideas from you guys about what, in your experience works best. |
| Posted by: Rudy Nov 15 2010, 11:07 PM | ||
*corrected for j00* Maybe, but the Car of Today isn't nearly as affected by it as the Car of Yesterday was, because of the grille's new location and the fact that most of the car's frontal downforce now is generated by the splitter. |
| Posted by: WillDearborn Nov 16 2010, 10:59 AM |
| Obviously a massive variation of both can cause folks to pick one side or the other. The real answer is there is no "most important." You build your car to spec and the class will have a minimum weight for you. From there, you work on streamlining. |
| Posted by: backalleyracer Nov 16 2010, 01:28 PM |
| I assuming because it is a race based upon cheapness, its easier to remove said glass and not pay for new plexiglass replacements and I agree with dearborn's answer, even with 4 posts |
| Posted by: MetalMan777 Nov 16 2010, 08:31 PM |
| Sorry, I keep forgetting not everybody is familiar with the awesome that is lemons. www.24hoursoflemons.com There's no minimum weight in this, or any of my favorite race series [read: can-am]. Some people have gone to enormous lengths to remove the entire body from their E34, leaving something you'd recognize as the same car, and putting up a roll cage where the roof once was. Yes, cheapness is key, but is it worth smashing out windows? Aero matters, a lot. Go ride your bike at 30mph, it'll make the air feel like soup. |
| Posted by: Rudy Nov 16 2010, 08:37 PM | ||
"It's not just for rich idiots, it's for all idiots!" Classy  |
| Posted by: MetalMan777 Nov 16 2010, 08:50 PM |
| Man, it's pretty clear how you're winning Carver's/Mobi's competition, what with your irrelevent posts. Try to stay on topic here, this is a serious, educational thread. In the interest of practicing what I preach, just take a look at the pictures of the cars on that site. http://www.facebook.com/album.php?aid=241861&id=36766739494&ref=mf I understand the cars that have silly things on their roof. They're more interested in having fun than in being as competitive as possible, and they accomplish their mission with high flying style, that or goofy shit on their roof. I don't know though. Crude aero elements, like a plastic undertray could be made for pennies with scrap plastic. I read somewhere that the Cobalt SS's top speed is drag limited, and if you swap trunklids with somebody who doesn't have the gigantic wing, you can get a few MPH at the top end. Stuff like that makes a difference, question is, how much? |
| Posted by: Jardim Nov 16 2010, 09:53 PM |
| These are concepts we can only know for sure (exact amounts) if we had an access to a wind tunnel. |
| Posted by: MetalMan777 Nov 16 2010, 10:00 PM |
| Well, that'll get you some data, but you can still test without one. That's what I plan on doing with my 6er before too long. I want to get it on a track, get some baseline laptimes, then add things, underfloor tray, tape on body seams, stuff like that and see what the difference is. |
| Posted by: backalleyracer Nov 16 2010, 10:20 PM |
| those thing will make a big difference in cooling for sure, as for pure speed, i am unsure there seems to be to many factors...tires, brakes, driver, changing road conditions. I think it would be unfair to say that aero would be the sole reason to faster lap times |
| Posted by: WillDearborn Nov 17 2010, 07:10 AM | ||
I'm very familiar with lemons and have driven in several of them. If you're worrying about aero in that race, you're going in the wrong direction. Nothing is taken seriously, aside from safety of course, and just about everyone makes their car look foolish on purpose, negating any type of aero advantage. Lemons is a war of attrition, nothing more. You are barking up the wrong tree in terms of questioning car design. Now, if you were doing some research for club racing or time trials then that would be something worthy of this discussion. |
| Posted by: sideways Nov 17 2010, 07:03 PM |
Have one mild contribution for the thread. Just sayin. Think about it. |
| Posted by: Rudy Nov 17 2010, 09:02 PM | ||
Dude, it was all in good fun, chill man. Seriously speaking though, LeMons is an absolute blast. I'd love to go see a real one, it would kick ass. As for aerodynamics, I always looked at the Atom and facepalm'd. How much more weight would it add just to merely add a skin and a fold-down plastic canopy over the roof of that car?  I'm sure that would have a considerable effect on its top speed above 140 MPH. |
| Posted by: MetalMan777 Nov 17 2010, 09:05 PM |
Ok, I'll bite. Image size reduced, original size: 750 x 498. http://www.pistonheads.com/pics/news/19841/Silv01176940-L.jpg to view the image in its original dimension. It's not a perfect argument, considering it weighs less than an Atom, but it's also much, much faster. As for lemons, perhaps it's a poor example, because they don't really run it as a race, so much as a circus. Chumpcar, though, is racing. It's also a battle of attrition, but every competitive edge helps, no? Edit: Drifter: Not if the Atom is redline limited. Which is entirely likely, considering it's purpose. I'd like to see one with a cockpit with gullwing doors or something resembling an LMP car. I'd also like to see it with a longitudinally mounted engine, but I have a hardon for longitudinally mounted rear engines. |
| Posted by: WillDearborn Nov 17 2010, 09:35 PM | ||
Both the Radical and the Atom are more gimmick than car. Radicals have small series use but are not practical for racing in the least, where as Atoms are not practical at all. Both cars are horrible examples of race cars. I'll restate: You need to look at actual racing classes. Chump car is another joke series just not as jokey as Lemons. Look at T1 or STO and see what they're able to do with what they're given within specs. In real racing classes they do not differentiate weight and aero as one being more important than the other. |
| Posted by: MetalMan777 Nov 17 2010, 09:59 PM | ||
Not practical for racing because it's slow or something? I don't really care about actual racing classes because more often than not they have limits on aerodynamic modifications. Lets look at CanAm, they were pretty much unlimited, till Jim Hall decided to make a car with a 50 horsepower vacuum pump on the bottom. That, and the Brabham fancar lead me to believe aerodynamics are more important than pretty much anything else. Ceteris paribus, a lower Cd and more downforce will make a car faster. And it's not like race teams publish the angle of attack of their wings. Looking at what an actual racing class does is more often than not, looking at the legal maximums. Lemons, ChumpCar, etc. are perfect examples, considering there's not a damn limit on weight or aerodynamics. There is only a budget, and that will not take into account canards made of scrap aluminum or the ilk. A massive carbon fiber wing would be questioned, and probably asked to be removed (probably not, in lemons it would likely be torn up, and in the other series, it would probably create more drag than it's worth). Subtle things like revised ducting make a difference, though, and I'd like to know just how far it goes. |
| Posted by: MattW Nov 17 2010, 10:51 PM | ||
Let me just point out, that they added the front splitter to take air away from the nose. Yes it makes no sense, but that's what it does. As per the question, the reason why you see *most* local track cars, or LeMons cars run without any windows save the windscreen, is because that's what the regulations state. For example, both out street stocks have full windows, 'cause the rules allow it. Most cars don't run any past the windscreen. All the "strictly stock" (street car with a cage pretty much) classes are forbidden to run any windows aside from the windscreen. There was a big stink with my buddies car from the tech inspector 'cause he replaced the rear quarter windows on his 240SX with pieces of sheetmetal(looked nice, more space for sponsors), but the tech inspector hated it because he constituted them as "windows." Needless to say, my buddy fought it and was allowed to keep them after the race director said that they didn't count as windows and were allowed. |