http://www.f1technical.net/news/201715.8.2 Engine exhaust systems must have only a single turbine tailpipe exit and either one or two wastegate tailpipe exits which must all be rearward facing and through which all exhaust gases must pass. All and only the turbine exit exhaust gases must pass through the turbine tailpipe and all and only the wastegate exhaust gases must pass through the wastegate tailpipe(s). None of the tailpipes may be contained within any of the other tailpipes.
5.8.3 The cross-sectional area of the turbine tailpipe exit at the rearmost point of the turbine tailpipe must lie between 7500mm2 and 14000mm2
, and the total cross-sectional area of the wastegate tailpipe exit(s) at the rearmost point of the wastegate tailpipe(s) must lie between 1590mm2 and 2375mm2. If there are two wastegate tailpipe exits they must be equal in area.
First a question to the turbo experts here: Will this really increase noise that much? Are they used all that often anyways? Also, can this be used to increase power somewhat?
And now, to one of my favorite past-times:
Gentlemen, start your loophole hunting!
First loophole proposal: Use the wastegate as an F-duct of sorts. If you point it cleverly and set it up so that it is not used until you reach, say 13000rpm, then you have an f-duct "on-demand".
The obvious drawback is that you must operate without the wastegate virtually all the time to avoid accidental activation... or maybe not? If you use 2 wastegate tailpipes, and only their exits are regulated, what is to stop teams from using a fluidic switch or similar so that one wastegate acts as a wastegate normal does while the second will only let air out above the said 13000 rpm? You get the best of both worlds. A car could be setup so that it hits 320km/h in 8th at 13000 rpm, so the f-duct equivalent would be activated only above 320km/h. Handy for overtaking. One could also activate it when desired at 280km/h in 7th, or at 240km/h in 6th... One problem though is that the engine would need to tolerate running such high rpms...
Loophole proposal number two: The two wastegate tailpipes sit exactly over the (turbine) exhaust pipe, in contact with it and with each other, and they just so happen to extend a bit further backwards and bend somewhat upwards...
In any case, who the hell thought that "wastegate tailpipe exits which must all be rearward facing" was a sufficient description of anything? Some suspension members are "rear facing" too... Edit: this one is nicely clarified below.