He wouldn't elaborate further on the vehicle, but did state: "That is going to be quite a special vehicle. Very difficult for one not to smile."
Manley made this revelation at an event held last week at Fiat Chrysler's Detroit headquarters to launch the concept vehicles for the 51st Annual Moab Easter Jeep Safari.
Above: Leaked images of the next-generation Jeep Wrangler Unlimited. Top: Jeep Grand Cherokee SRT.
The Jeep boss had previously said that a Hellcat-powered variant of the Grand Cherokee would debut by the end of 2017.
It's not clear if the Trackhawk's version of the Hellcat will be quite that powerful, but even if it isn't, it should be big step up from the Grand Cherokee SRT, which is motivated by a 344kW/624Nm 6.4-litre V8.