Little aero secrets
#47
Nice advices here!
But also extremely difficult to convert to 1/10. Even Colin Chapman failed to build working skirts in F1 1979
I really have to think about how to make skirts work on carpet and not getting stuck in the carpet or the car sides.
Rake is on my list for tomorrow.
Also nice would be a double chassis, like an undertray fixed on the hubs to maintain a stable clearance.
Oh man these ideas have a huge potential to empty my purse
But also extremely difficult to convert to 1/10. Even Colin Chapman failed to build working skirts in F1 1979
I really have to think about how to make skirts work on carpet and not getting stuck in the carpet or the car sides.
Rake is on my list for tomorrow.
Also nice would be a double chassis, like an undertray fixed on the hubs to maintain a stable clearance.
Oh man these ideas have a huge potential to empty my purse
#48
Tech Elite
iTrader: (2)
This is a useful link: http://www.thirdgen.org/forums/suspe...elly-pans.html
The goal is to get air moving fast under the body. Wing shapes work. But what seems to work best is kind of an inverse NACA duct? It takes air from the flat, and squeezes it up and vertically.
That said, rake and any sort of air control is probally miles ahead of what we have now. :-)
The used to sell ducts that would attach to the back of on road pan cars for this.
The goal is to get air moving fast under the body. Wing shapes work. But what seems to work best is kind of an inverse NACA duct? It takes air from the flat, and squeezes it up and vertically.
That said, rake and any sort of air control is probally miles ahead of what we have now. :-)
The used to sell ducts that would attach to the back of on road pan cars for this.
#50
Somebody needs to build a wind tunnel with force transducers and scales already or this can be debated forever.
#51
A diffuser is basically a very intricate NACA duct
Sorry about not having English voice-over, should be self explained though.
And this:
http://www.racecar-engineering.com/t...-aerodynamics/
Sorry about not having English voice-over, should be self explained though.
+ YouTube Video | |
And this:
http://www.racecar-engineering.com/t...-aerodynamics/
#52
Finished my undertray test some hours ago. I am not happy, but not sad either.
The positive first: You definitly feel the difference. The balance changed adding grip to the rear. So the diffuser did his work. I am not sure with the rest. The car definitely felt like it was pulled down on the straight and entered the fast corner more controlled. I also didn't need to brake as strong into this corner.
Now the negative:
The fastest laptime was very close to my todays best without undertray, but the consistency was very bad. Very few laps were within one tenth in succession. Most differed around two tenth. Without undertray I was within one tenth for 5-10 laps before a bad lap came and these laps were within the same tenth of my todays fastest. So the tight infield makes the car difficult to drive because it behaves unexpected.
Then the undertray needs a lot more ride height to prevent or at least reduce scrub. 2mm isn't enough, so the cars cog is rised significantly.
Indoor on high grip ETS-carpet I don't think a 1/10 tc chassis will benefit.
Lets end with a good thing: The undertray was tough enough to withstand a (small) crash and all abuse I gave it on track.
The positive first: You definitly feel the difference. The balance changed adding grip to the rear. So the diffuser did his work. I am not sure with the rest. The car definitely felt like it was pulled down on the straight and entered the fast corner more controlled. I also didn't need to brake as strong into this corner.
Now the negative:
The fastest laptime was very close to my todays best without undertray, but the consistency was very bad. Very few laps were within one tenth in succession. Most differed around two tenth. Without undertray I was within one tenth for 5-10 laps before a bad lap came and these laps were within the same tenth of my todays fastest. So the tight infield makes the car difficult to drive because it behaves unexpected.
Then the undertray needs a lot more ride height to prevent or at least reduce scrub. 2mm isn't enough, so the cars cog is rised significantly.
Indoor on high grip ETS-carpet I don't think a 1/10 tc chassis will benefit.
Lets end with a good thing: The undertray was tough enough to withstand a (small) crash and all abuse I gave it on track.
#54
Tech Regular
Ever since I started racing RC I had thought of making a small wind tunnel and use digital scales.
I don't think it would take too much to put the chassis and body on a 4-scale setup and turn on the wind and see the numbers.
I don't think it would take too much to put the chassis and body on a 4-scale setup and turn on the wind and see the numbers.
#57
Tech Regular
iTrader: (16)
[QUOTE=wtcc;14782996]Nice advices here!
But also extremely difficult to convert to 1/10. Even Colin Chapman failed to build working skirts in F1 1979
I really have to think about how to make skirts work on carpet and not getting stuck in the carpet or the car sides.
Rake is on my list for tomorrow.
Chapman did not fail. He succeeded exceedingly. Lotus type 79 "ground effects" car, for example. Outlawed by FIA because too much corner speed. Ironically all drivers that drove it felt safer considering so much more grip. Enter the 1500 turbos, 1800hp 1100kgs, more died during this era, ground effects + the turbo monsters would have leap frogged lap speeds 30 years!
The aero skirts worked very well, aluminum sheets in a verticAL channel with Teflon (I would assume) runners. Google Venturi effect.
But also extremely difficult to convert to 1/10. Even Colin Chapman failed to build working skirts in F1 1979
I really have to think about how to make skirts work on carpet and not getting stuck in the carpet or the car sides.
Rake is on my list for tomorrow.
Chapman did not fail. He succeeded exceedingly. Lotus type 79 "ground effects" car, for example. Outlawed by FIA because too much corner speed. Ironically all drivers that drove it felt safer considering so much more grip. Enter the 1500 turbos, 1800hp 1100kgs, more died during this era, ground effects + the turbo monsters would have leap frogged lap speeds 30 years!
The aero skirts worked very well, aluminum sheets in a verticAL channel with Teflon (I would assume) runners. Google Venturi effect.
#59
Chapman did not fail. He succeeded exceedingly. Lotus type 79 "ground effects" car, for example. Outlawed by FIA because too much corner speed. Ironically all drivers that drove it felt safer considering so much more grip. Enter the 1500 turbos, 1800hp 1100kgs, more died during this era, ground effects + the turbo monsters would have leap frogged lap speeds 30 years!
The aero skirts worked very well, aluminum sheets in a verticAL channel with Teflon (I would assume) runners. Google Venturi effect.
The aero skirts worked very well, aluminum sheets in a verticAL channel with Teflon (I would assume) runners. Google Venturi effect.
In RC road racing we can keep the skirts as close to ground as possible because there isn't a driver inside to be motion sick or affected by stiff wheel rates.
Correction: 700kg.
I've been thinking about doing that, should provide less drag.
#60
Tech Adept
iTrader: (14)
A long time ago I worked on an rc dyno - with a 5 HP 3-phase 240 motor connected to a fan. Air speed was about 60mph, so it was great for testing for velodrome racing. You probably don't need 4 scales, but you do need 3. Front wheels, rear wheels and one for drag. You can use a pulley connected to a weight and the car. The weight will sit on a scale. When the air goes over the body it will push on the car and lift the weight on the scale. The difference between starting weight and ending weight is the amount of drag. It is easy to get downforce; but hard to do it without getting more drag.