One of the few area free for engineers to tinker on F1 engines but one seldom discussed are exhausts. Teams change configurations all the time looking for an edge, often to suit the circuit, none more so than Red Bull.
Check out a package Red Bull brought to Silverstone. Note the coated headers and the heat shield cladding over the whole engine. This is likely all designed with an eye to keeping the internal aero workings of the car efficient and the exhaust plume as energized as possible.
Another development this week end is from Lotus who are finally deploying an reconfigured "double DRS", a way to stall the rear wing like the old "F-Duct" used to but without intervention from the driver (as mandated by regulations).
The air is collected in scoops next to the engine air inlet and then blown at low speed in the "monkey seat" zone. At high speed the flow is diverted to the periscope structure you see in the picture and up under the wing, making it stall. As you can imagine tuning this system has to be a mighty challenge but Silverstone will be the perfect testing ground.