did you dyno the engine before and after the exhaust mod without playing with the fuel ande boost? the reason i ask is on my hj 61 i dropped the exhaust just before the big standard muffler at the three bolt flange (so it only had the engine pipe attached to the turbo) and dyno ran it than hooked up original exhaust and re-dynoed and results were it lost torque and a single horsepower (1 bhp) with the 'exhaust dropped' although i hadn't played with boost or fuel. just a point of interest what boost is your engine running and what effects does it have, economy,power, reliability ect as i'm thinking of upping both fuel and boost but wondering what was the best compromise for the 12ht was with reliability economy and driveability being paramount. i don't want to destroy a great engine in search of max power or be unable to afford to keep fuel up to it
