I used Project White and the Bad Bish for the testing. It still took a long time to do it all, wanted the information though.

Yes, I feel the car with the wingless trunk and VG/no wiper probably is the best arrangement for the least drag. I'm also think the diffuser with the JDM EVO9 bumper makes it even better.

I have not tried the APR spoiler.

 

I have all the sensors to log downforce on my car. I'm on my second version of the setup. A couple things to note.

- The car actually creates lift, not downforce, in stock like trim. All of these things we put on the car remove lift and get the car closer to neutral. It takes big aero and lots of work to the bottom of the car to cross the threshold into downforce. The Cyber EVO with full aero makes around 50 - lbs of downforce.

- The car has a pivot point related to front-to-rear aero load. If you add "downforce" to either the front or the rear separately you will lift the opposite end. You'll note in the wicker bill photo that they also list the lift it added at the front. This is why creating a balanced aero system is important.

I'll be using the data I gather to build a custom rear GT wing that balances the loads I create with my front splitter, flat bottom, and rear diffuser.

 

Wow, interesting stuff.

 

David, thanks for a very informative video. One thing I'd like to add to the discussion, if you're just looking for a little bit of additional downforce over a completely wingless car, then a rear spoiler, like the one from Rexpeed type-C:



A wing like the stock Evo wing does create some downforce, but also creates a significant amount of drag - probably not something you'd be willing to compromise on a drag racing car.

l8r)

 

very nice post dave... i have a question though.

Do you think it would be beneficial to add aero panels to the underside of the car?

 

I do have an "aero panel" in the rear of the car and one for the front but not installed. Yes, I am personally confident there is a benefit from the rear diffusers like the one we build. The rear bumper cover acts like a parachute behind the car, closing it off and getting the air to flow under it instead of into it has to help, which is what we've done as can be seen in the video.

 

Sorry its my fault for not asking a more detailed question, but what I meant was over the center portion on the underside of the car, covering the driveshaft...? It may not be worth it, but sure would be interesting to test out.

 

just got time to watch the video, looks like you guys got some usable data, not bad .

 

Maybe you guys have some other footage not in the video, but it's important to have the camera mounted in the same location when looking to see airflow in a specific area related to a parts change. Using a case car is useful as well.

Cool article about tuft testing.
http://autospeed.com/cms/title_Aero-...7/article.html

 

Is there a difference between the USDM bumpers and the jdm bumpers aero wise?

 

To me it is just important to get out from behind the desk and do something, even more important than the placement of the camera...................

billyblonco, I'd have to say yes since the JDM bumper is cut short in the rear and it would have to eliminate some of the parachute effect the EVO8 USDM bumper has.

 

no block off plate for evo 9 bumper ?