Downhill Dino
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Are those grey (silver?) streaks on the side?
The Le Mans General Discussion Thread
- Thread starter arvin charles
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CodeRedR51
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- catamount39
Definantly the Nismo.Tail's way too short to be anything else.
AJ
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Well seeing as it has now been tweeted by @ NISMO, I think the guessing game is over. I believe it is a still from tomorrow's ad.
CodeRedR51
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AJ
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Sunday you mean.
Yes, sorry.
I'm in full race prep mode for the weekend now, so everything before the checkered flag is 'today' to me. 
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Has to its in the rules........that are posted......
Fin
A vertical rigid fin is compulsory.
This fin must be:
- Longitudinal and parallel to the car centerline.
- Perfectly located on the longitudinal axis of the car with
equal thickness either side of the centerline.
The fin must have a constant thickness (between 10mm
minimum and 20mm maximum).
With the car on its wheels, the visible area (in lateral view) of
the fin must be greater than 3000cm² from both sides.
The fin must be continuous without any holes or openings.
The inlet for engine air intake may be integrated in the fin, on
condition that all prescriptions of Article 3.6.3 are complied
with (except thickness that may not be constant over a
maximum length of 1400 mm).
No other device can be attached to this fin.
The fin can be integrally fixed to the engine cover and/or
fixed rigidly to the chassis, rear wing and rear structure (on a
"bridge").
Tools may be required to remove the engine cover and/or
the fin.
b/ Position
The top edge must be straight and situated between
1040 mm and 1050 mm above the reference plane.
The side projection of the leading edge must be straight and
situated at a maximum of 10 mm rearward of the windscreen
upper edge (cf. Article 3.3).
The top edge may be not straight in a zone comprised
between the leading edge and 100 mm rearward of the
windscreen upper edge provided it is situated no less than
1000 mm above the reference surface.
The windscreen upper edge is defined as the X position of
the most rearward point of the windscreen at Y=0.
The trailing edge must be straight and situated between
350mm and 450mm behind the rear axle centre line (except
the dimension of 350 mm, these constraints do not apply to
the rear wing support if it extends the fin).
The bottom edge may be no more than 25mm above the body work surface.
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- catamount39
The fin is required by the FIA for safety reasons (aka, so the car doesn't flip when spinning sideways).
- 3,264
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No, they took it off because it provided no gain. The "e-turbo" as it was dubbed, was there to reduce turbo lag. But as Toyota pointed out, an ers-h unit robs the engine of efficiency. What point would there be in running that?
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- cnd01
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- catamount39
- 9,089
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- cnd01
I'd argue it makes the car easier to flip when it's bouncing through the grass.
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- Furinkazen_54
I think i'll also attest that Le Mans is the only track where cars go such high speeds and physics are always going to win.
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- ROB__MK2
Ferraris, Ferraris everywhere
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Meanwhile back on planet Earth 
Ozz Negri signs with Krohn for the ELMS. http://www.racer.com/wec-le-mans/item/112999-negri-jr-set-for-europe-return-in-elms
Rocketsports working a P2 deal in WEC http://sportscar365.com/lemans/wec/rsr-finalizing-partial-season-european-lmp2-program/
KCMG and TDS will run the Oreca 05 P2 Coupe http://sportscar365.com/lemans/wec/kcmg-to-run-oreca-05-nissan/ http://www.racer.com/wec-le-mans/item/112968-tds-reverts-to-oreca-for-2015-elms
Ozz Negri signs with Krohn for the ELMS. http://www.racer.com/wec-le-mans/item/112999-negri-jr-set-for-europe-return-in-elms
Rocketsports working a P2 deal in WEC http://sportscar365.com/lemans/wec/rsr-finalizing-partial-season-european-lmp2-program/
KCMG and TDS will run the Oreca 05 P2 Coupe http://sportscar365.com/lemans/wec/kcmg-to-run-oreca-05-nissan/ http://www.racer.com/wec-le-mans/item/112968-tds-reverts-to-oreca-for-2015-elms
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- cnd01
The fin will push air away from it when sideways. If it's a lazy spin or just oversteer, it works great getting the car stabilized. Big performance advantages.
We all can agree that the basic principle of flight. Air moving quicker over the top side of a surface than the bottom of a surface.
The rear wing is essentially an upside-down airplane wing albeit small. At high speed, it can still produce massive amounts of lift. Watch Davidson's crash here: The fin pushes air over the bottom of the wing not only flipping the car but launching the rear highest into the air then flips the car back over by the same principle.
- 9,089
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Wow if you actually believe what you just said I'm worried
Also you've just contradicted yourself as well saying the rear wing cause it to flip after previously stating the fin would act a sail (a sail is curved btw like an aerofoil) causing a car to flip where as as per the regs I posted must be straight and flat(not an aerofoil shape)
That crash was caused by air getting under the car not by the rear wing causing it to flip or the fin
Also if you really want to be owned
or rather, some very rough calculations.
lets assume that when the car is sliding perpendicularly, the sharkfin has a Cd of 1.3 (a number I got from wikipedia for a simple flat plate perpendicular to airflow) and has an area of .827 m^2 (2325 * 355.6 mm, which i roughly got from the spotting guide and the total length of the car) and the center of pressure is halfway up the fin and dead center. we'll take the CoG height to be 6 inches above the ground, with the fin center of pressure 880 mm above the ground. Finally, lets assume that the car lifted off at about 90 km/h.
drag force = .5 * v^2 * air density * Cd * A
with SI units, Fd = .5 * 25^2 * 1.225 * 1.3 * .827
which in our case works out to 411.6 N.
Lets assume half the weight is on each side of the car, and assume Fg on that part to be 9.8 * 450 = 4410 N. We'll neglect downforce as the car was travelling sideways. The question then is can the fin generate enough moment to overcome the gravitational loading
the length of the overturning moment arm is .677 m (880mm - 6 inches) to the overturning moment .728 * 411.6 = 300 Nm
if we assume the track to be 2 meters minus half the tyre width (14 inches), the countering moment from gravity works out to be 3626 Nm.
Yes, its very rough, but its an order of magnitude difference. While it may have contributed, the sharkfin does not appear to have been enough to cause the flip over. I tried to use overoptimistic estimates, erring towards things that would help the sharkfin lift the car off the ground. I have neglected the lift effect from the floor. Thats fine; I'm only trying to determine of the shark fin was the culprit. That does not appear to be the case.
http://www.f1technical.net/forum/viewtopic.php?f=5&t=12908&start=120
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- 22,551
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- HamiltonMP427
I'm laughing cause the Sailing prodigy is right and the DP "in house" (his house) expert is only somewhat.
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