Whoopsy:
Rossi:
Would have been the ideal playground for the often rumoured tri-turbo setup of the new Turbo...
I suspect Porsche did tried initially but couldn't make the transition work to their satisfaction.
The small turbos would be working at their peak efficiency right around the switch over point and that's the most crucial moment for gas requirement for the smaller turbos, there just isn't enough left over gas to spool the bigger turbo up.
If Porsche could solve the packaging issue, a roots type supercharger would be perfect for the low end, say from launch to about 4000rpm, those superchargers are useless anyway at high rpm. Using supercharger would free up the exhaust gas to spool up a turbo and it can take over after 4000 rpm all the way to red line.
Roots type superchargers are monsters off the line, I loved the 55K engine in my old CLS55.
The tri-turbo rumor was quite consistent over the past couple of months before the 991 Turbo/S introduction and I really wonder what happened. It is an interesting concept and it certainly would have made the new Turbo more special (and probably more powerful too) but I kind of think that the tri-turbo engine is reserved for a different kind of car, maybe the rumored 960? Unless Porsche used the very same engine (with little mods) from the "old" 997 Turbo, I doubt that Porsche would have had the time and resources to switch engine development that fast from a tri-turbo to a twin-turbo setup. Especially since the new engine also supports EU6 environmental regulations, mandatory on new cars starting fall 2015. Since Porsche claims that 90% of the 991 Turbo/S is new, the engine can't be the old one. So did they just "remove" one turbo charger from the setup and re-designed it? Doesn't sound too likely. So maybe the tri-turbo rumor was a joke (maybe a journalist once asked a Weissach engineer what is new about the next Turbo and he joked "it gets a tri-turbo"... ) or the tri-turbo engine is actually for a different car.
Time will tell but I know one thing for sure: If Porsche comes up with a tri-turbo engine and/or more power for the 991 Turbo S within the next three years, a lot of customers will be very very p.ss.d. So this isn't very likely.
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RC (Germany) - Rennteam Editor Porsche Panamera Turbo S, Cayenne GTS (958), 991 Turbo S (Oct. 5th), BMW X3 35d (2013)