Originally Posted by
Dan Gerous
I read in a book somewhere that the Brit Tooms were more expensive and underpowered, compared the American engined examples.
Underpowered? No...
Spey - 12,250lbs dry, 20,515lbs reheat
J79 (GE-17) - 11,900lbs dry, 17,900lbs reheat
Unfortunately, the fuselage mods to allow the Spey to fit (wider intakes needed for increased mass air flow, deeper and wider rear fuselage) ruined the area ruling and increased drag to such an extent that much of the expected benefits of the increased thrust of the Spey were lost.
-RP