Ok... it's a Mustang piece. AJ Hartman runs a Mustang in NASA's American Iron and ST classes.

However, here is comparative CFDs of three different splitter designs that show the impact of front diffusers and endplates. He is doing a complete car and claims the CFD shows a CL of -2.7 over a surface area of 1.8m². I calculate that to be 1700 lbf of downforce at 100mph, LMP level numbers. Project Crusher- Part 3 - RHR Performance

 

Great tech. Thanks for sharing.

 

I should point out the builder says the front aero (which includes a fully ducted radiator, visible in the pictures, generates so much front downforce he has trouble generating enough rear downforce using both a 2-element rear wing and rear diffuser. He has a very interesting analysis on canards. In that, he has when set that develops over 100lbf downforce at 100mph but at the cost of nearly 40hp, another which generates 60lb at the cost of 5hp. A new approach to designing canards (C6 Corvette Project) Part 1 - RHR Performance

 

I should point out that the ST4 splitter does not look anywhere close to legal especially since a 4" blade splitter is the max allowed and that thing looks way the **** bigger than 4". Those fender mods and canards are not ST4 legal either. ST4 is supposed to have cost savings by not allowing crazy aero setups. Hell you can't even run the CR lip in ST4. Why is he publishing shit that isn't legal?

 

It is really a STU/1/2/3 splitter. I don't know why he labeled it ST4, possibly because he isn't familiar with the ST4 rule nuances.

The key would be the relatively high downforce levels in medium speed corners. High enough to affect spring rate selection and damping ratios. He as already posted on canards (he got around 60lbf at 100) and rear diffusers (about 150lbf at 100). The front splitter is the big number though, where he generating over 500lbf for less than 20hp drag.