S2000 Aerodynamics
05-22-2013, 05:48 AM
#1
Former Moderator
Thread Starter
S2000 Aerodynamics
I've been reading Competition Car Aerodynamics and been contemplating changes to the car. I moved my custom wing end plates forward and slightly lower yesterday after seeing that the low pressure under the wing can actually extend in front of the wing. The graphic also suggests the stock APR GTC 200 end plates aren't backwards after all.
The book says in regards to end plate size bigger is better until you get to crazy big, like larger than F1 wing mounts/endplates so my 12x12in end plates (max NASA PTx size) will not be trimmed.
I'm also going to modify my splitter's outside edge to bumper junction to try to keep the very high velocity air spilling around the splitter/bumper junction (white arrow below) from hitting the 255 wide front tire. The S2000's nose shape will cause even more air to flow to the sides of the car than the Ford Fusion NASCAR below. The drag caused by the high velocity airflow striking the tire may be the reason why my Mongo splitter was so slow. The book found no increase in drag when a splitter was increased from 4 inches to 6 inches of extension so something else caused the rise in lap times (possibly splitter flexing too).
Ford Fusion NASCAR Velocity Plot (red is high velocity, blue & green low--normally high velocity = low pressure and low velocity = high pressure)
The graphic below is a comparison between a car with an air dam alone and an air dam with a splitter. Red is high pressure, blue is low. You can see how the splitter reaches out and chops off the bottom of the high pressure bubble on the nose of the car. The high pressure also concentrates on top of the splitter which pushes it downward for downforce. The airdam alone creates a lot of low pressure under the car so adding the splitter doesn't add much more low pressure but it does move the low pressure forward which will put more pressure on the front wheels.
The author concluded that 100mm of splitter extension (about 4 inches) is the sweet spot. The book doesn't discuss splitter height (pisser).
The book says in regards to end plate size bigger is better until you get to crazy big, like larger than F1 wing mounts/endplates so my 12x12in end plates (max NASA PTx size) will not be trimmed.
I'm also going to modify my splitter's outside edge to bumper junction to try to keep the very high velocity air spilling around the splitter/bumper junction (white arrow below) from hitting the 255 wide front tire. The S2000's nose shape will cause even more air to flow to the sides of the car than the Ford Fusion NASCAR below. The drag caused by the high velocity airflow striking the tire may be the reason why my Mongo splitter was so slow. The book found no increase in drag when a splitter was increased from 4 inches to 6 inches of extension so something else caused the rise in lap times (possibly splitter flexing too).
Ford Fusion NASCAR Velocity Plot (red is high velocity, blue & green low--normally high velocity = low pressure and low velocity = high pressure)
The graphic below is a comparison between a car with an air dam alone and an air dam with a splitter. Red is high pressure, blue is low. You can see how the splitter reaches out and chops off the bottom of the high pressure bubble on the nose of the car. The high pressure also concentrates on top of the splitter which pushes it downward for downforce. The airdam alone creates a lot of low pressure under the car so adding the splitter doesn't add much more low pressure but it does move the low pressure forward which will put more pressure on the front wheels.
The author concluded that 100mm of splitter extension (about 4 inches) is the sweet spot. The book doesn't discuss splitter height (pisser).
05-22-2013, 06:37 AM
#5
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Great info. I wonder what the effects of a radiator air channel that vents out of the hood like the voltex widebody s2000 or the AMS Evo X TA car has on the high pressure bubble at the front. I see it as having two fold benefit of additional cooling and acting as a large spoiler on the front end, creating down force.
05-22-2013, 07:25 AM
#6
Former Moderator
Thread Starter
I created an S2000 Aerodynamics web page.
I'm also considering adding some small aluminum dive planes for the lower front bumper. With so much lateral air flow around the nose the dive planes should work well to add some downforce to help balance the rear wing downforce.
I'm going to attempt to bend some 1 inch aluminum angle stock to follow the top of the rear trunk edge between the wing supports to act as a short spoiler to add some downforce with very little added drag. I'm going to try a 30º spoiler angle.
