Aero design question

[botsapper]

I could suggest to look at GTM-R cars for 'decent' design with some aerodynamic-tested shapes for inspiration. It was awarded 'Best Exterior Design' at last year's SEMA show. It has a lightweight tube-steel rolling chassis mated with a rear/mid-mounted V-8 but could see other engine/powertrain donors. Check their site for more info:

GTM Photogallery

Revenge shows new GTM-R ‘Super Car’ in Detroit - MotorAuthority - Car news, reviews, spy shots

Another inspiration (styling purposes) for great looking 'kit' car, power-mated with your Honda engines. Not pure aero because it is a roadster but an aero roof and aero studies could be added to the base. Pics of their racing coupe.

K-1 ENGINEERING - Fotogaléria

[theunchosen]

If you are really out for Cd having your passengers in tandem would go alongway towards that.

Then your design could be more torpedo like, lol.

Seats low slung angled somewhat heavily backwards( I think you wanted rear wheel drive? that might not have been something you were looking at) and the engine could be mounted behind and a little under the second seat.

Cooling you could use small fins on both sides like the Bentley Speed 8.

http://members.fortunecity.com/freec..._speed8_02.jpg

You would want to angle them so thay are pulling air from a lower point to a slightly higher one to increase downforce on both sides. OR instead of using it for cooling you could ram-air if you wanted to go that road.

The original designs for the Speed 8 called for the rear-view mirrors(side view mirrors) to be mounted on the wheel guard and the front to be slightly more tear than it is(which would put the fairings on the front right tire higher than the rear ever so slightly).

I would go with Tandem for coolness sake let alone the potential enormous gains you in Cd you might be able to reap from the much decreased frontal area and potential stability.

[rkcarguy]

The GTM is actually pretty close, sans the wide flares and side intakes. The honda engine is pretty narrow and would also allow the passenger compartment to be further back.
Looking at the K-1 racing cars, those look awesome and despite a few things are pretty close. I'll take a roller please
My plan was to top mount the radiator almost horizontally and scavenge some air from the "channel" and route it the the radiator and out a grillework below the rear window.

The problem is with most of these cars, is that they are designed to provide alot of downforce for racing, but will probably be heavier at speed than not in motion. For a balance of mpg and safety, I think you have to have a _____# car that weighs the same on each wheel at 100mph as it does sitting in a parking lot.

[winkosmosis]

You can design a car so that otherwise useless drag is turned into downforce

[theunchosen]

haha I'm sorry, I was not saying you should make it exactly like anything that races, but if you go similar and drop the wing you lose all the racing downforce and can add back as much as you need for stability at highway speeds.

[botsapper]

I suggested those two examples for exterior design inspiration. It looks like you have a clean sheet design. You've already settled on your cooling configuration at a downstream horizontal plane, hopefully redirecting cool air from your underside flow channel. Not sure about steady flow because the upward sloping belly pan is a low pressure plane. Just like the sample, Bentley Speed8, the top roof scoop has high pressure flow for the engine air ingestion. Efficient cooling NACA inlets & scoops will need to be placed at high pressure surfaces. You also have an engineering target of the 'magical' zero lift at any/all speeds. For handling safety, agitated gusts, large-vehicle vortex turbulences, & crosswinds are held in check at higher speed limits by useful downforce. A lesson learned, just check this out.

http://www.youtube.com/watch?v=TtV1D...layer_embedded

[rkcarguy]

I knew what this was before I even looked at this movie, I was watching this event on TV when it happened.
It'd be interesting to see how this car performed in wind tunnel testing, if it got "light" as speed increased to begin with. I think in general, a lighter vehicle must be smaller to obtain a density such that it won't be subject to the wind gusts, pressure waves from passing vehicles, etc. Many of these lightweight race cars that are very wide and low, create a near perfect shape of a wing and coming over a little knoll with a headwind is all it takes.
The amazing part was the driver walked away from that IIRC...
On a different subject, I found a local place near work that makes fiberglass bathtubs and shower stalls using the chopper gun sprayed fiberglass. While it's not optimum, I could certainly have them spray their stuff into a mold taken off of the aluminum bodywork to save some weight and make parts reproducable.

[ALS]

You would be amazed at what can be done to a normal car to get the Cd down.

Normal 1969 Dodge Charger was probably close to .40 plus Cd





Throw on a new nose, flatten out the rear window and presto a .28 Cd car.





Rear wing was that tall so you could open the trunk lid.

[botsapper]

It looks like you are more comfortable with metal fab but wood is easier to work with. The basic plywood buck is soo much easier to create & modify. Any experienced FG fabricator are familiar with styling bucks and can assist you with the creation of your FG body sections. Even before creating these bucks, depending of your CAD/CAM experience all of your work could be kept in database & be tested with many different fluid flow programs. There are tube chassis design programs to help design a balanced, lightweight yet strong structure. A lot of your assumptions can be easily tested and a whole lot of fab time saved.

Car Body Buck in Plywood

[theunchosen]

Using sprayed in FG could be. . .risky. I've had FG cary body parts explode on the highway from rocks. It makes a lovely mess.

If you wanna go FG all you need to do is get a mold fabbed, put a liner down, lay Fiberglass cloth(Fiberglass Cloth in bidirectional weave) coat in resin and fixative and sit and wait. It heats up a little you wait 45 minutes pop it out sand, smooth paint bolt.