The Rocket was designed for a 100 ft lb of torque from the 1.6 Focus engine. Lots of builders used far more power seemingly without issue but the MKII was designed to be stronger. Rocket also suffered from straight line sensitivity, even worse with a quick rack. This issue is also address in MKII. Success of Excoet which is far cheaper and easier to build has meant that Rocket has now been replaced by Exocet.