Aerodynamic Discussion Thread
#182
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I know you don't have time to, but showing us colorful pics, graphs and schematics oh I love schematics (jk on the schematics) would be more beneficial
#183
Here is some reading to look at, pay attention to paragraph 3, keeping air out from underneath, para. 4 and para 5 mentions the air dams purpose and F1 and indy car design add ons. The little side bar window on page 3 talks about the side skirts on a stock car which are riveted on and made from ABS to keep air from rolling under the car sides and creating lift.
My idea has always been to keep the air out from underneath my car not invite it under unless I'm willing to smooth the whole underside and add a rear difusser to help get the air out from under the car. Adding a upward sloping splitter in my opinion is letting more air under the car without an effiecent way of getting it out on our undersides unless you are willing to smooth the underside and add a well designed difusser with an upward angle of no more then 9* seems to be the max number most reading has said to not exceed or you well stall the air in the difusser. I have seen the spliter on the nascar cars and it is wider then the front bumper as it should be but it is not very deep back under the car, it sole purpose is to trap air on top to create downforce not increase the flow of air underneath the car. That is why I run 949's air dam up front and it also has spats that deflects the air up over the car side and tires which helps keep it from curling underneath along with the side wings I added over the winter.
I am no aero engineer but I have done alot of reading and been racing for 50 years off and on and sure don't know everything.HowStuffWorks "Stock Car Lift "
My idea has always been to keep the air out from underneath my car not invite it under unless I'm willing to smooth the whole underside and add a rear difusser to help get the air out from under the car. Adding a upward sloping splitter in my opinion is letting more air under the car without an effiecent way of getting it out on our undersides unless you are willing to smooth the underside and add a well designed difusser with an upward angle of no more then 9* seems to be the max number most reading has said to not exceed or you well stall the air in the difusser. I have seen the spliter on the nascar cars and it is wider then the front bumper as it should be but it is not very deep back under the car, it sole purpose is to trap air on top to create downforce not increase the flow of air underneath the car. That is why I run 949's air dam up front and it also has spats that deflects the air up over the car side and tires which helps keep it from curling underneath along with the side wings I added over the winter.
I am no aero engineer but I have done alot of reading and been racing for 50 years off and on and sure don't know everything.HowStuffWorks "Stock Car Lift "
#184
Read paragraph 4 in this article. HowStuffWorks "NASCAR Racing Physics 101". If I was to build a splitter I would use the nose like crusher uses and build the splitter to extend out forward as much as I wanted for downforce and that could change with which track I was going to run but I would not run it back under much as to speed the air flow under the car with a large surface and running it into a stock undercarriage. The main reason I don't run a slitter is I like to do off track excursions and having to pick up 949's air dam in 3 pieces and glassing back together is enough work for me. LOL!. Again just my 2 cents worth.
Last edited by jmann; 05-25-2013 at 01:51 PM.
#185
Here is a 2011 cot road course splitter and a used one for a porsche, check out the price used, and we think we spend money for something that gets tore up easily. http://www.ebay.com/sch/i.html?_trks...at=0&_from=R40
#186
muddy waters
While air is fairly predictable, I think it muddies the waters to talk about race cars with rules, and cars that are free of regulations. NASCAR and F1 operate under the strictest of rules, and if they were free from them you'd see their aero packages change drastically. So the "why" in racing is most often rules-based.
If you chuck the rule book you may end up with a bunch of Delta wing shaped cars with suction fans sticking out the *** end, active aero, and all sorts of other nonsense.
If you chuck the rule book you may end up with a bunch of Delta wing shaped cars with suction fans sticking out the *** end, active aero, and all sorts of other nonsense.
#188
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Read paragraph 4 in this article. HowStuffWorks "NASCAR Racing Physics 101". If I was to build a splitter I would use the nose like crusher uses and build the splitter to extend out forward as much as I wanted for downforce and that could change with which track I was going to run but I would not run it back under much as to speed the air flow under the car with a large surface and running it into a stock undercarriage.
When I create my front splitter, it will include a diffuser section running back to where the stock undertray mounts now.
#191
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There's still plenty of work for the engineers, but the gains they are chasing are much smaller.
#193
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It occurs to me, for those of us chasing aero advantages and not bound by any form of competitive rules, that examining what is prohibited in these series could be advantageous.
I don't know that anyone on this forum is well funded enough to create a sucker miata. But limitations on diffuser depths and areas - side skirts - wing widths, chords, etc - any form of passive aero limitations are worth exploring. If it was limited, it must be for a reason, right?
I don't know that anyone on this forum is well funded enough to create a sucker miata. But limitations on diffuser depths and areas - side skirts - wing widths, chords, etc - any form of passive aero limitations are worth exploring. If it was limited, it must be for a reason, right?
#194
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And copying aero components blind, without understanding how what they did ties specifically into the rest of their car, doesn't always work out so well. Witness the number of teams that were unable to get the exhaust-blown diffuser to work for them.
#195
It occurs to me, for those of us chasing aero advantages and not bound by any form of competitive rules, that examining what is prohibited in these series could be advantageous.
I don't know that anyone on this forum is well funded enough to create a sucker miata. But limitations on diffuser depths and areas - side skirts - wing widths, chords, etc - any form of passive aero limitations are worth exploring. If it was limited, it must be for a reason, right?
I don't know that anyone on this forum is well funded enough to create a sucker miata. But limitations on diffuser depths and areas - side skirts - wing widths, chords, etc - any form of passive aero limitations are worth exploring. If it was limited, it must be for a reason, right?
#196
I got won a competition that gives me engineering services from a company named Creaform. They not only make their own scanning machines, but offer FEA and CFD engineering. I'm really looking forward to them running some CFD on the bodywork, including the diffuser, splitter, and even air flow through the engine bay.
This stuff is as much art as science, as there are so many parameters that it takes someone with some talent and experience to accurately set up the tests, and then decipher the output.
This stuff is as much art as science, as there are so many parameters that it takes someone with some talent and experience to accurately set up the tests, and then decipher the output.
#197
I always thought that splitters work by exploiting the high pressure area where air hits the airdam/bumper. Provide a horizontal surface for that pressure to work on and you get lift or downforce. In the example pictured there is a horizontal surface both above and below the airdam, so that entire section will produce zero nett downforce. The added area is of no use at all.
#198
Its not always that complicated guys, though more often then not it is.
I always thought that splitters work by exploiting the high pressure area where air hits the airdam/bumper. Provide a horizontal surface for that pressure to work on and you get lift or downforce. In the example pictured there is a horizontal surface both above and below the airdam, so that entire section will produce zero nett downforce. The added area is of no use at all.
I always thought that splitters work by exploiting the high pressure area where air hits the airdam/bumper. Provide a horizontal surface for that pressure to work on and you get lift or downforce. In the example pictured there is a horizontal surface both above and below the airdam, so that entire section will produce zero nett downforce. The added area is of no use at all.
#200
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Its not always that complicated guys, though more often then not it is.
I always thought that splitters work by exploiting the high pressure area where air hits the airdam/bumper. Provide a horizontal surface for that pressure to work on and you get lift or downforce. In the example pictured there is a horizontal surface both above and below the airdam, so that entire section will produce zero nett downforce. The added area is of no use at all.
I always thought that splitters work by exploiting the high pressure area where air hits the airdam/bumper. Provide a horizontal surface for that pressure to work on and you get lift or downforce. In the example pictured there is a horizontal surface both above and below the airdam, so that entire section will produce zero nett downforce. The added area is of no use at all.
On this forum, if you post with authority as an expert on a subject, about which you actually know very little, you will get hammered.