I was looking in vain for an aero forum. Two questions:

1) For race/track S2000s, when fitting a front splitter, was front diffuser design and air exit path from the diffuser an important consideration or a consideration at all? This is a picture of an Evasive-built car's Voltex front splitter; the diffusers are visible on either side. As in the rear, the purpose of the diffuser is to increase the speed of the air under the flat section in front of the diffuser, reducing its pressure and increasing its downforce (or reducing its lift). A diffuser exiting into the wheel well would require the wheel well to have sufficient air exits to prevent pressure build up. Some prototypes now seem to have the top of their fenders cutout.



2) Was ducting placed before and behind any radiator, oil cooler, or intercooler to force all incoming air into the heat exchanger core and to seal the air flow exiting the heat exchanger, ducting it into a low-pressure area. That low-pressure area is usually near the front of the car behind the leading edge of the hood and well in advance of the windshield. These are pictures of the Top Fuel S2000 time attack car, showing the radiator and the hood exit. Cooling airflow is a significant part of the car's overall drag, and it can also affect downforce.



Some of the folks here have done significant fabrication, and many treat their racing seriously. Many make their own splitters

Have you approached either of these areas?

 

This is a CFD of a small Indian van which was being analyzed for increased cooling efficiency.

 

This article about the Viper ACR's front aero also provides some insights: Composite wing key to high-speed stability https://www.compositesworld.com/arti...ability#.WerFU


The article says the front splitter has 7 distinct diffusers. Additionally, they used canards which the article says created vortices that helped extract air from the wheel wells.

 

These time attack cars are talking about "Infinity wings". They appear to be a wrap-around combination of splitter and canard, with a fence that they say keeps the air out of the wheel well.

 

If you need some real race car inspiration:
Nerd’s Eye View: Chevrolet Corvette C7.R > MotoIQ - Automotive Tech, Project Cars, Performance & Motorsports
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Ferrari put out a video on the active aero of the F488:

Porsche video of the active aero of the 911 Turbo:

The vids give some streamline visualization.

 

The cutouts on the wheel wells of Prototype cars is to prevent the cars from going airborne when the cars get sideways. The Prototypes had a tendency to take flight when the cars spun out sideways at high speeds; the cutouts give he air an escape path instead of lifting the cars up.Front downforce can be increased by using louvers on the tops of the fenders which is very common on German DTM cars and Japanese Super GT cars. The downside is increased drag. So they can tweak the size of the louvers depending on the requirements of the specific track.