Interesting Aerodynamic Cars (Mike Vetter's ETV, also Avion)

[aerohead]

Compare to 2006 Pontiac Solstice,Cd 0.45

[freebeard]

Here's something that might/could go in the 'Spotted in the Wild...' thread, but I'll put it here.

Fark.com ran a thread titled 'If you drive 10 mph under the speed limit there's a 50% chance you're drunk. So hit the gas. For the children. For yourself. For society '

Mid-way through the first 50 comments (I seldom read more than the first 50) please find:

mudpants
1 day ago


No man, just trying to save gas man. Hipermiler !

It's a small world after all.

FYI: Fark.com ate my hot-links

[kach22i]

Originally Posted by freebeard

Mid-way through the first 50 comments..............Mudpants

FYI: the images appear as little squares and I cannot seem to copy the source to see the images.

McLaren F1 XP GT Longtail....New York Auto Show
Random TRANSPORTATION pictures - Page 1477 - Pelican Parts Technical BBS

Originally Posted by enzo1

Just about any car which has a "LongTail" version has got to be more aero than the standard version, right?

Other angles:
@FYUTURE Tumblr


https://twitter.com/AutoBant/status/573467553885978625


Somehow this tail just does look as aero as the old Porsche 917 LongTail which I know a French aerodynamicist put though a wind tunnel to obtain higher top end speeds on.

[freebeard]

FYI: the images appear as little squares...

They're hot-linked from Fark.com. Maybe you have a filter on? At least aerohead can see them. I didn't want to get myself in trouble with a direct link but here goes: FARK.com: (8656910) If you drive 10 mph under the speed limit there's a 50% chance you're drunk. So hit the gas. For the children. For yourself. For society Only bad people read Fark.

It's a picture of aerohead's T-100, the 166mpg Metro and the Honda 600 with the Barracuda backlight. All seen here before.

The longtail is nice but the color doesn't show it off very well.

[aerohead]

*The top is oversaturated
*The upkick spoiler only adds drag
*There's no plan taper at all,so there can't be any pressure recovery/base pressure increase
*I suspect that it's all done for very high speed stability.They don't want their customers killed driving their products.Very bad P.R..

[kach22i]

This is bound to get comments, but I'm posting it anyway.

Random TRANSPORTATION pictures - Page 1479 - Pelican Parts Technical BBS

[freebeard]

If you don't want us to comment, just ask.

I wonder why the plan taper in the rear fender fades away below the wheel center.

[kach22i]

Originally Posted by freebeard

If you don't want us to comment, just ask.

I wonder why the plan taper in the rear fender fades away below the wheel center.

Comments are welcomed, I just know that anything which looks like a high down force race car holds a certain amount of disgust for one of the forum posters. I'm trusting they will see past that and delve into some other aspects of this design.

To address your observation, good eye.

Let's see, if you narrow an opening the air accelerates and the pressure drops. Therefore if you do the opposite (per the detail in question) and expand the opening then the air slows and the pressure increases.

I'll go ahead and guess that slowing the air a bit near the ground plane at the rear lower corner reduces the energy of a drag causing vortex located there.

The higher pressure at the lower corner (plus that outward angle) delays the air from being sucked in behind the car too rapidly.

My guess is that it lowers the drag, but most likely not just in a straight line going straight. Race cars have to perform in turns at off angles as well (in turns), and this may prove to be the more relevant aspect of this design.

Then again, maybe this is a failed design never to be repeated, and we were just assuming it works.

If it works too well, the rules officials will find some way to spoil it and maintain mediocrity. This is why most race car designs should not be emulated or admired for aerodynamic efficiency.

These are designs which simply comply with man made convoluted rules to insure a "level playing field" or "mutually assured mediocrity".

More on the car in question.

Nissan GT-R LM Nismo
Nissan GT-R LM Nismo - Wikipedia, the free encyclopedia

the GT-R LM is unique amongst Le Mans Prototypes for utilizing a front mid-engine layout for its internal combustion engine as opposed to the rear mid-engine layout used by nearly all other competitors in the category.................................

the GT-R LM powers the front axle through a gearbox located in front of the engine.

Big at the front, skinny at the back (at least internally), there may be something to like about this non-wedge design.

http://www.roadandtrack.com/motorspo...gt-r-lm-nismo/





The value or importance of internal aerodynamics and or air-flow.................could be the start of a new thread?


http://www.autoevolution.com/news/ni...ery-91820.html


I found this, not sure about the accuracy of the source though. Other sources refused to list the C of D and said "unknown". It does appear to be from the official company website though.

http://www.nissanusa.com/performance...ics-modal.html

.35 COEFFICIENT OF DRAG

.35 is the kind of drag coefficient you expect from a minivan, not a race car. But there’s a reason for that: downforce. To create downforce, you always have to cope with the penalty of some drag. When it comes to keeping the GT-R LM NISMO® glued to the track at 220MPH, finding the balance between maximizing downforce and minimizing drag is key.

[freebeard]

I was, of course, kidding.

It certainly isn't built for driver ingress/egress. And the cut-outs in the fender tops aren't for wheel jounce, as the fronts end at the axle centerline.

Na-na-na-na-na-na, Nis-mooo

[kach22i]

Originally Posted by freebeard

And the cut-outs in the fender tops aren't for wheel jounce, as the fronts end at the axle centerline.

I don't know if that is part of the race rules for percent of "open wheel" or more part of venting the wheel well.

I suppose this is yet another example for the regulations obscuring optimized aerodynamics and perhaps at times common sense.

http://www.f1technical.net/forum/vie...hp?f=5&t=21401

I wonder if the Nissan will use the "coanda" effect to attach the exhaust plume on the outer skin of the car toward the back end.

Reader comment above aside, more pictures in the link below.

http://www.dailysportscar.com/2015/0...-pictures.html