Smoothing out the bottom...

[island911]

I would think that one would want to open up some area infront of the front wheels.

[Zeke]

dd, I think if you do the font half, the back half will take care of itself. I get my experience from lay down karts at Willow. And, the tracks are rough on AL, as you can see from Chuck's pics. The AL doesnt; bounce back. Who doesn't go off once in awhile? In karts, on OTE and it's a complete redo. Plastics work vey nicely here.

I posted months or years ago about Kydex. Lexan works good too. Plexiglass is to brittle. ABS is very good and a bit pricey, like the Lexan.

I looked over the bottom of the RS Spyder for several minutes. Nice and smooth with a curvature making the center lower. Any way to push or extract the air too the sides and, of course, the venturis out back. They start about the last 3rd.

[RSBob]

Weight? My less than professional job probably weighs 1 lb. It is not designed to take hard impacts, but stay put and smooth the flow.

[Bill Verburg]

Originally posted by island911
I would think that one would want to open up some area infront of the front wheels.

The area around the wheel wells is one of the dirtiest parts aerodynamicly, it gets the full force of the wind, and add in tubulance from air egressing it can be a real issue. When yawed as when cornering the shaped sides can actually develop quite a bit of aero side force.

I like Chuck's idea "getting the low hanging fruit". But there are much better places to get lunch.

[Bill Verburg]

Easist thing to clean up the rear is to take a p/u chin spoiler, trim it, and mount it just ahead of the rear sway and trans area.

[Shuie]

Anybody have a pic of the under belly of a Yellowbird? Did Porsche give them a flattened unibody or did they make there own panels?

[Bill Verburg]

Originally posted by Shuie
Anybody have a pic of the under belly of a Yellowbird? Did Porsche give them a flattened unibody or did they make there own panels?

Here is the bottom of a CTR,
front

rear


and all the parts(exploded)


No rear belly spoiler, despite the rumors to the contrary

[Shuie]

Thanks, Bill.

[ChrisBennet]

Hmmm, in the Ruf video they Yellowbird they show the smooth underbelly. The Yellowbird was more of a prototype CTR. Maybe the found the smooth underbelly wasn't worth it.
-Chris

[tcar]

Would a large air dam on the front do more than a belly pan?

I can see the advantage of a pan under the engine; to keep my garage floor clean.

My interest in this subject is voyeuristic. My SC is a daily driver.

[randywebb]

Remember 2 things:

- this will help much only at fairly high speeds - how much time are you spending there?? IF a lot, then you guys must be on ovals...

- and the lowest hanging fruit was picked when Ferry put the motor in the rear -- the long expanse of underpan in the front and middle of the car is in pretty good shape since there is no motor in front to mess up the air flow

Nonetheless, I encourage people to experiment and post real data -- if they can collect it. A model in a water tank would be ideal for testing. You'd have to scale to Re.

I'd start with a forward scoop/spoiler/splitter, the sheet that Chuck pictured and the lip that Bill mentioned.

Tyson's point is fundamental - don't reinvent the wheel. No glory in that.