Typically, longer-wheelbase cars are more stable at high speeds and have efficient downforce (there's more space/surface area for generating downforce). The downsides of a longer car are obviously weight, and to a certain extent, a slight agility disadvantage in tight, slow-speed corners. Mercedes seemed to have engineered around that issue in '19.godlameroso wrote: ↑Sun Jan 12, 2020 2:44 amWouldn't you lose some aero platform stability by shortening the wheelbase? Also you'd have to rely more on the bargeboards to seal the floor which has the potential to choke the floor and diffuser with too long a wheelbase? Maybe a shorter wheelbase allows you to use a strong vortex from the bargeboards without choking the diffuser like a long wheelbase would?
High-rake cars will produce more underbody downforce from the underfloor than a low-rake cars with the same floor area. This is due to the expanding space behind the small gap between the floor’s leading edge and the surface of the track itself. Higher-rake helps boost diffuser performance. Low-rake cars require a bigger floor to get the equivalent downforce of higher-rake ones.
Low-rake cars' downforce comes with a smaller drag penalty (i.e., better efficiency) and they have a low CoG, which helps with handling and in turn, tire management (Merc was the class of the field in this area in '19).
To your original point, increasing the rake and shortening the wheelbase is going to add some drag. Sounds like they're trying to rectify their cornering problem at the expense of their straightline advantage, which was a combination of their efficient design and whatever was going on with the PU.