So here are my suggestions for the game (sorry if some allready have being talk about):
About turbo and supercharger:
Combine turbo and supercharger on the same engine. Like WV 1.4 TSI engine, Volvo´s new 2.0 engine petrol engines and the old Nissan Micra super turbo.
Triple turbo for the inline engines (like BMW M550D diesel engine. A inline 6 3 liter diesel whit triple turbo and 381 HP and 740 NM) and Quad turbo on V12 and V16 engine.
variable turbine geometry maybe.
The game have twin turbo, but how about biturbo. Means a small and a bigger turbo on the same engine.
i now this can be a tricky one but how about compound turbo also.
Engine:
Will we se 2 cylindre engines in the game (like the fiat twinair 2 cylindre engine)?
W engine. Engines whit W shape cylindre. Most nown engine of that type must be the W16 engine in the Bugatti Veyron and W12 WV/AUDI use.
2 stroke engine maybe?
Brakes:
I asume drum and disk brakes made of steel comes to game, but how about ceramic brakes disk and pads?
different materials for all of the car like, engine, boddy and undercar and so on. materials like metal, plastik, aluminium, titanium, carbon fiber?
Thats what i have for now. Sorry my bad English.