I am the one who is responsible for the aero on the car.
When building our current aero was leaning torwards more the factory GT3 direction, then the MINES
The MINES lip is a good option, however it lacks in many areas as it was designed for "dual duty" with street driving being very important and to be used with the Mines rear wing which doesn't produce much.
Most of our tracks in the usa require a bit different aero balance then say Tsukuba, which is short, tight and requires the front of an awd car to work extremely well.
We (TopSpeed) have been working on the Aero of the GTR now for the last few years, and even last years aero package produces more downforce then anything available to the public today.
Learing from real world results of what actually works and not some calculated equation we have started working on a whole new package.
With this aero package I didn't want to kill the airflow under the car like the more traditional splitters. Example would be our last years front splitter as well as the other options available from companies. While this will move the aero balance over the front tires and produce a good amount of front grip, it does so at a loss of loosing rear aero from the lack of suffient air flow under the car to make the rear diffuser effective. Best example I can give is why nascar runs no diffuser. Once you kill all airflow under the car from a front splitter or airdam the rear diffuser is nothing more then useless weight.
Last years splitter required us to run a much larger rear wing then what was necessary to balance out the front since we lost so much from the rear diffuser. So never being happy with good enough we are working torwards a better overall balance without having the large amounts of drag.
I think were headed in the right direction as we were able to run 5 mph faster down the back straight while making 80whp less then previous our previous aero setup. All the while our min corner speeds were also higher, indicating an increase in overall corner grip.
We still have a bit of work to do, as we are only in the development stages. Already I want to make a few minor changes that will make a large difference. Rest assured as well once we are done we will be testing it all in the wind tunnel.