So heres how id do it if i was rich enough to try something this worthless.
Engine:
4 rotor, peripheral port, twin turbo. 4 rotors can make 750+hp in NA form and are roughly as large lenght wise as an american V8, plus much narrower. Small turbos would be used at lowish psi to act as a torque builder, because of the porting the engine wont have much low end torque. Id also create wastegates and diverter valves which are electronically controlled to bypass the engine when off throttle, diverting air back intoo the hot side of the turbo with a touch of fuel. This in escence makes it a jet engine while off throttle. Meaning it keeps rpm, and you have a nice antilag system that doesnt harm the engine. This can also be used to blow exaust into parts of the car, but i would stay away from that due to heat complexities. Expected hp, 1200+. Unrealistic? No, heres a 4 rotor turbo making 1664hp.
http://www.youtube.com/watch?v=coXB3xd6VK8
No kers, but it will have a overboost function. Pretty much locking the wastegates shut and building as much boost as it can. This will be linked with DRS to make a single straightaway speed button.
Gearbox:
7 speed double clutch box. More than 7 gears gets confusing. And while a cvt would be possibly better it would remove a lot of the fun in the car. The car will be awd similar to the ferrari ff. the main 7 gear box for the rear wheels after 100mph, and under 100mph a cvt box runing the front tires will help with getting off the line.
Chasis:
Carbon tub three seater, mclaren f1 style. Reason is to help move the engine a bit more forward. This to fit the large fan ducting.
Downforce makers:
Most of the main downforce comes from the fan driven underbody. It is powered by oil pressure. And with an adjstable pressure valve to limit the maximum oil pressure to drive the fans, you could also be able to control the downforce onboard using this valve. The fans themselves are 2 counter rotating fans, im thinking roughly 15-20 inches in diameter. Centrally mounted. The oil pressure system would keep the car from needing to be constantly at high rpm to have downforce, but it would still need a certain rpm for peak downforce. Thats why the valve is there, it controls how much pressure actually drives the fan. So theoretically at 5k you could hold the same pressure as the engine kept revving higher. Holding peak downforce for everything above 5k. This also reduces load when driven on the street.
The front end will have a wing mounted similar to many group c cars. The front wing will be adjustable from inside the car, again to help set the car up better for each track without needing a team of engineers. Since it is a mid engine car the front can be quite short/low and used mostly for aero reasons. Side intake radiators/oilcoolers/etc can handle the engine fine. Though i would use some of the air entering the nose to cool the front brakes and also duct it in front of the front wheels to create a curtain of air like the bmw 1M, this will reduce drag significantly.
Rear wing is the pop up type. Also adjustable. Single element. Both wings can have a DRS mode to set themselves to minimum downforce with the push of a button.
Body:
Similar to the noble M600. Adding changes to accommodate the wings and fan. The front cant be lowered much due to road laws.
Suspension:
design wise im sticking with double wishbone front and rear. Runing hydraulic pushrods fw14b style. Each wheel and chasis point will have arrays of small sensors to determine between all of them the current attitude of the car, how the road is, and link this to information from the drivers imputs to adjust the suspension and ride height tp maintain the best seal on the ground and optimum performance to the tires. Im thinking gyroscopes, accelerometers, and laser rideheight monitors should be sufficient. Plus all of those are pretty small and lightweight nowadays.
Tires:
This is the toughest part. The make or break point of the car. Id rather find this out after testing the dynamics of the car and compare tires not just by performance but by how easy they make the car drive. Its no use having a tire that will be .2s faster if youll crash in 2 laps.
Brakes:
This would be limited by tires and reliability. You could mount the same brakes the 458/enzo/zr1 use using 2 disks per wheel and a custom single caliper or dual calipers for each.
After all of these fun ideas we do have a problem, weight. id like to get it under 1000kg wet at a maximum. After that as low as possible will be ideal. This will mean very thin parts of carbon bodywork and fancy materials used in drivetrain parts. Maybe using a chain instead of driveshaft for the front wheels awd? Minimalistic interior will help a ton here. And an asmathic A/C wouldnt hurt. So minimal creature comforts can be used, but still enough to not be a chore to drive the carto the track.
