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Anyone have Aero questions?


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11 minutes ago, TiredBirds said:

On a side note, I was close to buying one of these.. it is clone based on a 240z 

ferrari-250-gto-1962-replica-tribute-clone-other-makes-1.JPG

You should run one! But you might have to come out to the west coast where they allow Ferraris to run:

Another clone, this time a Fiero with a 308 body. Not sure why they keep breaking hubs, we've never had an issue.

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Disclaimer: I have no formal aerodynamics training and most of this info I am going to share I have just picked up on the side for fun. Feel free to critique anything I am about to say.   I

one more before i hit the road.  not quite.  The air being directed over the top of the car does add downforce. It's not the temp to blame, it's the speed. So to make downforce, the general

Put a hole in the top of the fender above your control arm/spindle/whatever. Attach a rod to the top of your control arm that is long enough to protrude above the fender at full droop. Mark the rod at

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porsche919evo.thumb.jpg.24b4784ffa82cb6768254076ff59f560.jpg

 

Interesting that they use the end plates for mounting but also have a shark fin in the middle to support the wing.

 

How much deflection would be acceptable if only using end plates to mount a wing? As long as the AoA doesn't change, would there be adverse effects?

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37 minutes ago, mender said:

Interesting that they use the end plates for mounting but also have a shark fin in the middle to support the wing.

 

 

 

I would think that big  plane in the middle would keep air cleaner and flowing front to back as opposed to going/mixing across the car.  No?  FWIW too, that middle fin looks huge, is it bigger than the WEC spec?

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On 1/15/2020 at 11:13 AM, thewheelerZ said:

 

I would think that big  plane in the middle would keep air cleaner and flowing front to back as opposed to going/mixing across the car.  No?  FWIW too, that middle fin looks huge, is it bigger than the WEC spec?

 

That was the 919 Tribute car:

 

For the ‘Porsche 919 Hybrid Evo’ the entire hardware of the power train remained untouched. The 919 is powered by a compact two-litre turbo charged V4-cylinder engine and two different energy recovery systems – brake energy from the front axle combined with exhaust energy. [...]

The WEC efficiency regulations limited the energy from fuel per lap by using a fuel flow meter. At the 2017 championship round in Spa, in the Porsche 919 Hybrid’s final season, it could use 1.784 kilogram/2.464 litres of petrol per lap. The V4 combustion engine’s output back then was around 500 HP. Freed from these restrictions, equipped with an updated software but running the regular race fuel (E20, containing 20 per cent bio ethanol), the 919 Hybrid Evo delivers 720 HP.

The amount of energy from the two recovery systems that could be used in Spa 2017 was 6.37 megajoule. This was by far below the systems’ potential. On his record lap Neel Jani enjoyed a full boost of 8.49 megajoule – the e-machine’s output increased by ten per cent from 400 to 440 HP. [...]

Compared to the car in race trim, the dry weight was reduced by 39 kilograms to 849 kilograms. To achieve this, everything was removed what isn’t needed for a single fast lap: air-conditioning, windscreen wiper, several sensors, electronic devices from race control, lights systems and the pneumatic jack system.

 

The Jalopnik article didn't cite the aero changes directly but I remember reading that the undercar aero as well as the wing were modified, which I assume included the shark fin.  

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The shark fin was added years ago to prevent blow over when the rotated perpendicular to direction of travel.

 

There was a crash at Monza that showed the need for the change - 

 

 

Then Allen McNish proved it worked in 2011, you can see the "leading edge", drivers right of the car try and lift up, but it never happens.

 

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47 minutes ago, mender said:

I'm not asking about the aero effect of the shark fin, I'm asking about the need (at our level) to support the rear wing in the middle when it has end plate mounts.

Stand in the middle and see if it bends. If it does, you need a third mount. If it doesn’t, you built your wing too heavy :)

(Conceptually I like full end mounts with nothing in the middle, build the wing strong enough to not need the middle mount. The Porsche has the shark fin already and they probably said “well, it’s already here, why not add a small extension to support the wing?”)

Edit: I think the support on the Porsche has more to do with laterally stabilizing the shark fin than supporting the wing. 

Edited by enginerd
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3 hours ago, bbaker480 said:

 

That was the 919 Tribute car:

 

For the ‘Porsche 919 Hybrid Evo’ the entire hardware of the power train remained untouched. The 919 is powered by a compact two-litre turbo charged V4-cylinder engine and two different energy recovery systems – brake energy from the front axle combined with exhaust energy. [...]

The WEC efficiency regulations limited the energy from fuel per lap by using a fuel flow meter. At the 2017 championship round in Spa, in the Porsche 919 Hybrid’s final season, it could use 1.784 kilogram/2.464 litres of petrol per lap. The V4 combustion engine’s output back then was around 500 HP. Freed from these restrictions, equipped with an updated software but running the regular race fuel (E20, containing 20 per cent bio ethanol), the 919 Hybrid Evo delivers 720 HP.

The amount of energy from the two recovery systems that could be used in Spa 2017 was 6.37 megajoule. This was by far below the systems’ potential. On his record lap Neel Jani enjoyed a full boost of 8.49 megajoule – the e-machine’s output increased by ten per cent from 400 to 440 HP. [...]

Compared to the car in race trim, the dry weight was reduced by 39 kilograms to 849 kilograms. To achieve this, everything was removed what isn’t needed for a single fast lap: air-conditioning, windscreen wiper, several sensors, electronic devices from race control, lights systems and the pneumatic jack system.

 

The Jalopnik article didn't cite the aero changes directly but I remember reading that the undercar aero as well as the wing were modified, which I assume included the shark fin.  

fuel conservation on a race car? jeeesh

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I noticed you guys have built a Miata.

 

Do you have any numbers -- simulated or real -- for ride height versus downforce for a flat floor + diffuser?  Thoughts also on diffuser angle on this chassis?

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5 hours ago, KoneKillah said:

Would vortex generators on the A pillars create a protective "Shield" to direct air around the the open windows? I'm thinking of what F1 does around the sides of their underbody.

not sure but I'd like to use Vortex heads

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On ‎1‎/‎15‎/‎2020 at 10:33 AM, mender said:

porsche919evo.thumb.jpg.24b4784ffa82cb6768254076ff59f560.jpg

 

Interesting that they use the end plates for mounting but also have a shark fin in the middle to support the wing.

 

How much deflection would be acceptable if only using end plates to mount a wing? As long as the AoA doesn't change, would there be adverse effects?

The support on that car also houses the DRS actuators.

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3 minutes ago, TiredBirds said:

wonder if it is worth it on a 305? 

No numbers off the top of my head, but would imagine its worth something to get 15 yr newer chamber design and a slightly lighter head.

 

Edited by Team Infiniti
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