What happens if I lower rear wing
Discussion
They can make you an extra one with more 'stickie' to EXTRASTICK
Alan,
We have tested the car without the rear wing and proven that it will not go any faster (accel or V-max), but that it will adversely affect the car's stability and cornering capability above 100mph.
I've never reduced the height of the wing, but I'd almost guarantee that it will be a similar situation to removing it altogether.
Simon Hucknall
Press Officer
Noble Automotive Ltd.
We have tested the car without the rear wing and proven that it will not go any faster (accel or V-max), but that it will adversely affect the car's stability and cornering capability above 100mph.
I've never reduced the height of the wing, but I'd almost guarantee that it will be a similar situation to removing it altogether.
Simon Hucknall
Press Officer
Noble Automotive Ltd.
micknall said:
Alan,
We have tested the car without the rear wing and proven that it will not go any faster (accel or V-max), but that it will adversely affect the car's stability and cornering capability above 100mph.
Simon Hucknall
Press Officer
Noble Automotive Ltd.
How can this be? if it affects the cars handling it must be producing drag and therefore it must reduce the cars top speed - albight it might not be by very much but it still must affect the top speed.
Guy,
You're right, it makes little sense. But there are obviously other aerodynamic factors at play. Lee and I did the testing together with the 3R and the M400 and there was practically no difference in performance. If you want further proof, Autocar removed the wing from an M400 and folded the mirrors back and could still not improve on the time set with the wing in place.
Simon Hucknall
Press Officer
Noble Automotive Ltd.
You're right, it makes little sense. But there are obviously other aerodynamic factors at play. Lee and I did the testing together with the 3R and the M400 and there was practically no difference in performance. If you want further proof, Autocar removed the wing from an M400 and folded the mirrors back and could still not improve on the time set with the wing in place.
Simon Hucknall
Press Officer
Noble Automotive Ltd.
Where the wing sits the air is pretty "dead" and hence (from my short degree level aerodynamics course), the wing will produce downforce, but it's entirely possible that it will also end up "cleaning up" the exit of air from the rear, and reducing the drag from the blunt rear of the car.
If I recall correctly, blunt rear ends create a sort of reverse vacuum that effectivly pulls the car backwards, sticking a wing to push the air further up lowers this effect, but can increase drag.
Perhaps (and I'm no expert here) the two effects are cancelling themselves out?
One interesting thing is when Danny Rippon was at VMAX @ Brunters the difference was ~7mph between wing off and wing on, but when Autocar did the same they didn't get any difference. Head / tail winds obviously change things therefore as well, so unless you want to play around and have the time at a place like Brunters it's all a bit inconclusive me thinks!
J
If I recall correctly, blunt rear ends create a sort of reverse vacuum that effectivly pulls the car backwards, sticking a wing to push the air further up lowers this effect, but can increase drag.
Perhaps (and I'm no expert here) the two effects are cancelling themselves out?
One interesting thing is when Danny Rippon was at VMAX @ Brunters the difference was ~7mph between wing off and wing on, but when Autocar did the same they didn't get any difference. Head / tail winds obviously change things therefore as well, so unless you want to play around and have the time at a place like Brunters it's all a bit inconclusive me thinks!
J
joust said:Not cancelling each other out but working together!
Perhaps (and I'm no expert here) the two effects are cancelling themselves out?
Although I don't think the wing is high enough on the M12 to have any great effect on the downforce!
It's difficult to desribe without pictures but imagine the car without the spoiler, the laminar flow over the car is going to be disrupted because as you say the "blunt" rear end of the car will induce an element of pressure drag as it falls off the back. It's not however going to fall like a lead balloon, instead it will taper off gradually due to an adverse pressure gradient caused by the area of low pressure coming over the car (read about Bernoulli's equation if you want to know more). I think Bernoulli calls this effect "flow separation" but I've always called it Pressure Drag and the result is a series of tumbling swirls behind the car which pull rather than push because of the pressure difference. This effect is also why the back of your car gets dirty, the low pressure is effectively a vacuum cleaner pulling dirt off the road and splattering it all over your car! Anyhow...
Now if you add a wing into the equation you've got another laminar flow and another turbulent air flow being generated, however, because it's over a wing and it's streamlined the downforce is greater and therefore it should provide more grip. However, and here's where I hypothosise as I've not got a wind tunnel (there is one up the road from me though!), the height of the wing on the M12 is not high enough to go above the turbulent air coming off the car body and as the such the streamlined flow coming off the wing becomes turbulent and it's effectiveness is reduced.
I assume the wing must have some effect though because if you look at the end plates on Lee's Race Car wing (M12-2) they are significantly bigger than the standard ones and the only reason you'd do this is to stop wing tip vortices, something that has come out of the wind tunnel development no doubt - or just Lee's brilliance! Thinking about it, if you drive at some pace through mist or rain you can see the vortex being generated in the mirror, I've noticed it a couple of times, so there must be some force being generated by the wing.
As a side, the way the F1 teams use to test drag (before they could all afford wind tunnels!) was to drive the cars at 70mph, with no wind in a straight line. Take their foot off the accelerator and calculate the time it took to decelerate to 50mph. Repeat this test with the wing removed or adjusted and calculate the deceleration from a=(v-u)/t - where v is the final speed and u is the initial speed and t is the time (in seconds).
In summary, to gain any performance benefits I guess the backend would need a redesign and that will be evident in the M14 but I'd be surprised if it comes with a wing and even more surprised if it doesn't handle better than the M12!
I don't normally get involved with technical topics but I needed a break from work and just my 2p.
Anthony
Another closet aerodynamicist.
Well when I was at Bruntingthorpe last I did the same as Danny - Danny actually witnessed it as well (I think I actually had his son in the car) after many repeated runns - there was a 5 MPH difference in top speed - however it was still pulling both with and with out... Methinks we need a bigger runway 
Whilst I believe air travels over either end of the wing it was proved by PC that at 100mph no air travelled over the middle part of the wing, the air is stalled coming over the roof when it gets to the vertical rear screen. Witness a leaf stuck in the vortex there, it'll follow you up to silly speeds, a sloping rear screen ala exige would help as the air flow would stay laminar to this and be directed to the wing, a Kamn tail as seen on the Exige would also help the airflow from the rear of the car.
I confirmed the no air over centre part of wing with a Noble development engineer who was looking at, amongst other things, little lip spoilers on the trailing edge of the roof to try and stop the vortices.
I confirmed the no air over centre part of wing with a Noble development engineer who was looking at, amongst other things, little lip spoilers on the trailing edge of the roof to try and stop the vortices.
m12_nathan said:
Whilst I believe air travels over either end of the wing it was proved by PC that at 100mph no air travelled over the middle part of the wing, the air is stalled coming over the roof when it gets to the vertical rear screen.
So you could test this by counting the numbers dead flies in different areas of the wing; it should be nice and clean in the middle part!
Tell me is this why the cabin gets so stuffy? I mean aircon is mandatory even when you don't need the cooling!
--
Richard
chillidog said:Yep - there were absolutly zero flies on the middle part after my trip down and back to Le Mans, where as the outsides were absolutly caked in them!
So you could test this by counting the numbers dead flies in different areas of the wing; it should be nice and clean in the middle part!
J
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