Lol.. Seriously what's the diff between a splitter that is 10 mm from the surface and 100 mm?

 

I'm not so good at teh maths, but I would say 90mm.

 

The further out the splitter extends the more air it will force above the car.

Pretend I was driving my car down a deep snowy road. Think of what splitter would catch more snow. The long splitter will grab more snow and keep it above the splitter and force it above the car.

 

Ironically I tested my splitter in the winter. If it handles snow load it's good. It didn't. I'm not talking about distance outward. I understand that. I'm talking bout distance off surface of road

We're looking for a Venturi behind the splitter right?

Lol@ Dave

 

Interesting:

 

Lets not hijack this thread any more - this discussion belongs maybe in my Evo Aerodynamics thread.

 

The biggest reason for the undertray is the ground effects (Venturi). The closer to the ground you get the undertray/splitter, The better it works.

It's also why the velocity above and below the car isn't as significant as it would be for an airfoil in open air (like a tall rear wing).

The rear diffuser volume is what drives the underbody, but don't make it to steep to cause flow separation 7-10deg seems to be the norm). Sealing off the side skirts with the ground also keeps the higher pressure air along the side of the car from spilling into the underside reducing the speed and increasing the pressure.

 

I saw that on the original race date it snowed at top and was hailing in the middle! Lol

Gotta love hillclimbs, The mountain is in charge!

 

By the way does anyone know if any part if this will be televised or streamed?

 

It'll be on a local am radio station. You might be able to listen online.

 

it was sopposed to be streamed live this year. not sure if thats changed since the change of date but we can check!

 

To a certain extent yes, but not alway. I read a an article on a wind tunnel test of a Jaguar or Aston Martin GT car where they tested various undertray heights. If they went too low they eventualy reduced downforce. This was several years ago, so my memory could be foggy.

It's also the same article where I got the idea for the wicker in front of my hood vent. It was "accidentally" tested and I know it works.

 

We ran a floating undertray on older Uta fsae cars. It was fixed at about an inch off the ground and didn't fluctuate with speed from downforce, suspension travel from bumps, and it worked fantastic. Only problem was it was very heavy due to needing to be very rigid (only four mounting points at exterior corners). Our later fsae cars still incorporated the undertrays, but it was sprung aero and would fluctuate with speed and suspension travel. Even still, it worked well without any dramatic drop off in downforce when compression was high. I also read that to low can cause a drop off in downforce, but it has to be nearly scrapping the ground before that happens

 

Any updates for race weekend coming up? The big show is almost here!

 

Flying out Thursday to see the hill climb! Good luck to all the Evo drivers. Hope everbody makes a full run on Sunday!