Aerodynamics-- request for project help - PeachParts Mercedes-Benz Forum

hetiticth · #27 11-04-2015, 11:47 PM

Quote:

Originally Posted by Mxfrank

Having done projects like this, I have one thing to say to you:

SNAP OUT OF IT!

First off, that car looks like it will be an aerodynamic pig. The big frontal area, sloping rear, tumblehome and pointy tail look slick, but will result in high drag. If you were serious about building a vintage German aerodynamic design, then the car to build would be the BMW Kamm back. It was a milestone with regard to aerodynamics, but not much to look at:

BMW 328 Kamm Coupe (1940)

Milestones - Automotive Engineer

As far as budget, you'll need a kings ransom to build that car and make it work. I would budget $250,000 with no complications. And there will be complications. A Lesco transmission will probably cost your whole allowance, much cheaper and better to use a BW T5, and hunt up a set of straight cut gears.

After you've spend a quarter mill on the body and chassis, do you really want to use an SBC crate motor? At least use an M3 motor. But let me stop here and say again:

SNAP OUT OF IT!

A quarter of a million? Are we talking USD here?
I can't imagine ever having it cost that much.
Let me run up a quick list, if I use all new parts:
Lenco ST1200: $10,000 max
BBC: $15,000 max
Carbon Fiber (body panels): $5,000
Chrome Moly Tubing: $10/foot (the most expensive I saw) @ say.. 200ft.
Chrome Moly Tubing: $2,000
IRS: $5,000
IFS: $5,000
Extra Misc. Goodies: $8,000
Total:$50,000

That is assuming that I don't decide to design and fab up something myself for the suspension, and also that I buy a complete and assembled block.

The sbc350 would only be for a 'proof of concept' type build. It won't be in the final build. The final would have a big block Chevy.
I'm going with Chevy, because I have a lot of experience working on Chevy motors, and the parts are cheap and readily available.

I would argue that the design of the car I'm basing this off of is more aerodynamic than the one by Kamm. Look at this:

This is just a very basic image, but it explains a lot. Fluid dynamics show that the ideal shape is a teardrop.

The tail is quite useful in reducing drag. What Kamm had designed, where the tail is cut off at a certain point, achieves most of the aerodynamic benefits of the tail design. The end was cut off in order to cut off materials and size from the vehicle.

I'll look into your suggestion, I could always be wrong.

I'm not really looking to replicate a car. I'm using the Maybach as a starting point for my own design, though it will likely end up looking very similar.