EVO Aerodynamics Review
If you look at my design you will see it is in fact held by steel cables. The only problem is it still only sits 2" lower then the bumper itself, so I have a good 2"s of travel. I think it would load just fine into an enclosed trailer, but my currant ghetto ramps would need about 20' of 2" x 12" to geton the trailer...
It took me 3 splitters and 4 years of tweaking the mounting to get mine where it is now - on or off in under 5 minutes flat! I still hate doing it, though. I need a pit crew . . . 
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Joined: Sep 2006
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From: East Hampton Ct.
Dave - Just to be clear, I wasn't trying to say your aero setup is wrong or needs improvement, simply different than what I have learned/been taught. Where did the inspiration for the design of the rear diffuser come from? It looks like the diffuser begins forward of the centerline of the rear tires?
For your side skirts - did you have to cut or clearance the front doors or fenderwells at all?
I can relate to the loading/unloading pain of having the splitter. I take it off and put it back on every time the car goes on or off the trailer. This is my 3rd revision, but I finally got the mounting setup very solid yet comes off in 2 minutes with just 4 bolts you can reach by sticking your hand up under the front of the splitter. . .
For your side skirts - did you have to cut or clearance the front doors or fenderwells at all?
I can relate to the loading/unloading pain of having the splitter. I take it off and put it back on every time the car goes on or off the trailer. This is my 3rd revision, but I finally got the mounting setup very solid yet comes off in 2 minutes with just 4 bolts you can reach by sticking your hand up under the front of the splitter. . .
I can't discuss the underneath design. I can say that I had the chance to view the Letterman/Rahal ALMS BMW M3 up close and they run a true flat bottom car. I mean-absolutely flat as a laser. Charlie built a tunnel car that is not flat like the BMW. It takes it,s look and purpose from the 80's IMSA designs. Some of the really wild Porsche 935's come close. The side skirts wrap onto the body like a glove. No body needed to be altered. The diffuser which properly should be called tunnels, starts at about the rear axle line. They are made from solid aluminum composite panels. Plexi glass extensions go down to the same clearance as the side skirts. The rear bumper has been sealed and certain areas have been left open to discharge heat from under the body. Heat has been a concern and exiting the exhaust out the passenger side should help. Loading is pretty easy, with the exception of setting up the ramp assemblies. The car's splitter and low side skirts just clear. The only real pain is the dyno shop I use has ramps that require the splitter being removed. This direction will be key to competing in Super Touring as the top Corvette's are building flat bottoms for next season.
l8r)
Here are some quick mock-up pictures of my new rear diffuser development. Taking the model to DHP tonight to get it started. DHP did the diffuser for CBRD's Time Attack car. I think that was V1.0, and this one will be DHP Diffuser V2.0 
Leading Edge - will eventually extend all the way up to the front of the stock gas tanks:
Leading Edge - will eventually extend all the way up to the front of the stock gas tanks:
Sweet. I'd also like to see it with the different size tunnels like the C6R has in the pictures a couple pages before. Forget the reason but something like the air is more disrupted closer to the tires and the smaller gap uses more downforce or something. Would also be cool if it clears when loading/unloading on the trailer as we've discussed.
looking good!!
I know of at least 3 guys that ran it last year. I've heard good and bad reviews whether it really created downforce or not. I want to know if people run it because it works, or because it's a good option that's readily available, fits as shipped, etc.
Please speak up!
Last edited by boomn29; Jan 18, 2011 at 08:04 AM.
I'll say it's better then most in it's price range. It isn't a 3D splitter like the DHP but that's outta my price range atm. The way i've got it setup its very solidly mounted. I recently added AMS's front member which gives you provisions for the primary frame blots on the APR splitter. Add that with the front "arms" and the lip fasteners and she's on there. I may end up doing a better arm/cable mount for the very front of the lip as the "arms" they give you are puny little sh*ts I keep loosing hardware for.
Experience wise it does produce some downforce....compared to a flat tray or nothing at all. At high speeds she's much more stable in the front and more predictable on braking. Now the rear needs attention
Experience wise it does produce some downforce....compared to a flat tray or nothing at all. At high speeds she's much more stable in the front and more predictable on braking. Now the rear needs attention
I ran the APR splitter last season and would agree that it created downforce and helped keep the car stable. It made enough downforce that it kept trying to pull the lip off of the bumper and I had to reinforce the lip with additional screws to help hold it in place.
Maybe not the best thing out there, but definately better than nothing in my opinion. I agree that it does need better supports on the front holding it up. The two they give you are not enough. There needs to be at least one on each of the far corners as well, not just the center. From several on track pictures last year I could see it flexing out at the sides.
Mounting it to the chassis would definately have helped some as well.
Maybe not the best thing out there, but definately better than nothing in my opinion. I agree that it does need better supports on the front holding it up. The two they give you are not enough. There needs to be at least one on each of the far corners as well, not just the center. From several on track pictures last year I could see it flexing out at the sides.
Mounting it to the chassis would definately have helped some as well.