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Post by Stiggy on Mar 13, 2017 16:53:41 GMT
I have seen lots of laser cut flat plates used to fit wings but they can flex side ways. Often they are bolted to the chassis rails with riv-nuts which may not be sufficient. Having experimented in the wind tunnel at MIRA we found the most effective position and angle. We have now developed aerodynamically shaped mounting legs. These can be bolted to the rear cover. Loads have been assessed and even at high speeds there is no flexing as the legs are mounted near the corners of the rear cover and 50 mm diameter washers are used on the end of 4 x 8 mm threaded rods to secure. We are now pleased with the result, properly tested, study fixing and of course the option of colour coordination or contrast. I will be adding end plates in orange for the purple one, they are being powder coated at the moment but should add to the drama.  |
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Post by dietcoke on Mar 15, 2017 6:15:28 GMT
That's entirely too much wing angle, lol. Thing's gonna be a parachute tilted 30 degrees
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Post by Stiggy on Mar 15, 2017 10:06:42 GMT
That's entirely too much wing angle, lol. Thing's gonna be a parachute tilted 30 degrees Expert aerodynamicists tested the wing and experimented with the angle and height. They measured drag and down force with the most sophisticated equipment. The angle is adjustable on our legs should anyone wish to fix a wing at an angle that has not been tested in a wind tunnel. |
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Post by papabear on Mar 15, 2017 12:42:54 GMT
Did the test car in the wind tunnel have a windscreen? Your airflow right before the wing looks smoother than I would expect to see with the exposed roll bars. Or is it perspective and the wand was in the middle between the bars? Looks like the test car had the double hump bar installed.
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Post by johnp on Mar 15, 2017 14:15:36 GMT
At Stiggy 's request: we did loads of test runs Stewpot, with wings/without/with screen/without and so on, most at 60 mph simulated to 100 but the smoke tests were at 40 mph. The results are very interesting and will be a feature in CKC by Ian Stent, as spotted by eagle eyed Nige. It will be the issue with the Stoneleigh guide in, the biggest of the year in fact. |
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Post by Stiggy on Mar 15, 2017 14:19:59 GMT
The smoke stream in the top picture is flowing over the highest part of the roll bar.
MIRA aerodynamicists ran the following wind tunnel tests;
1. With a screen.
2. Without a screen.
3. With a fly screen.
4. With the rear wing turned through 180 degrees to wrap around rather than points to the rear.
5. Rear wing tried at 3 different heights.
6. Rear wing tried at 3 different angles.
7. Ran with our front twin wing fitted.
8. Run with alternative cycle wings.
9. Run with 185 then with 225 tyres.
10. Final run with front/rear wings and screen removed.
Each run had data print outs for drag, yaw, lift/down force.
Conclusions;
Wide tyres add significantly to drag. Cycle wings must be fitted tight to tyres and cover full tyre width.
Curved screen adds significantly to smooth air flow and lowers drag.
Front wing smooths air in front of tyres and created an amount of down force.
Only minor increases in down force were recorded with rear wing fitted at various angles.
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Post by jsmith on Mar 15, 2017 22:49:27 GMT
Is the yellow roller tube bender in the background the one you use to bend the main tubes?
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Post by kiwicanfly on Mar 15, 2017 23:16:41 GMT
Wide tyres add significantly to drag. But help going round corners among other things. Cycle wings must be fitted tight to tyres and cover full tyre width. I have found the RTR cycle wings too narrow for my 205 tyres to point where stopping them rubbing became an issue, I am thinking of splitting mine and putting a strip down the centre to gain more width and fit them closer. Curved screen adds significantly to smooth air flow and lowers drag. Curved sideways or up and down? Front wing smooths air in front of tyres and created an amount of down force. is this down force simply from the wing aerodynamics or from the tyres due to the change in flow over them? Only minor increases in down force were recorded with rear wing fitted at various angles. Do you mean regardless of the angle the increase in down force were only minor compared to no wing or does a wing help but the angle is not too critical. |
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Post by Stiggy on Mar 16, 2017 9:57:08 GMT
Wide tyres add significantly to drag. But help going round corners among other things. Wide tyres/wheels have a weight penalty and take more effort to heat up. A wide tyre on a light car on a wet surface is not the best approach.Cycle wings must be fitted tight to tyres and cover full tyre width. I have found the RTR cycle wings too narrow for my 205 tyres to point where stopping them rubbing became an issue, I am thinking of splitting mine and putting a strip down the centre to gain more width and fit them closer. The RTR cycle wings are made for 195 tyres not 205Curved screen adds significantly to smooth air flow and lowers drag. Curved sideways or up and down? The rake is important but the curve also helps air flow off the sidesFront wing smooths air in front of tyres and created an amount of down force. is this down force simply from the wing aerodynamics or from the tyres due to the change in flow over them? The front wing scored a double whammy. It smoothed air flow around the front of the tyres (air being pushed forwards due to rotation) and also added down force due to shape/angle/surface area. That is why we opted for a twin set up.Only minor increases in down force were recorded with rear wing fitted at various angles. Do you mean regardless of the angle the increase in down force were only minor compared to no wing or does a wing help but the angle is not too critical.
The rear wing needs to be high enough to attempt to work in undisturbed air, increased angle help a little but not a lot, BUT they do look cool. |
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Post by Stiggy on Mar 16, 2017 9:59:55 GMT
Is the yellow roller tube bender in the background the one you use to bend the main tubes? No, that is to dry/mangle my clothes with! In our fabrication shop we have a fancy roller with a motor that is very accurate, that one in the picture makes me wheeze when I use it! |
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avi
Newbie
Preparing to strip
Posts: 11
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Post by avi on Jun 20, 2018 22:48:57 GMT
I’m going to bump this thread as I would certainly be looking for rear wing option (BGW) when I order my kit. Predominantly so that people question the size of my manhood rather than the aero properties.
I note that some recent build threads that there are wing supports welded to the frame by MEV a la the US spec., and this pleases my eyes much more than a tank cover mounted option. Are these spaced to fit any specific wing? Any photos ?
What is the current offering for wings with the kit ?
Thanks
Andy
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