Does someone know the difference, why " J"-engines have from 135 to 155 HP? I would like to get the best performance from my engine and have therefore the following questions: - How is the best adjustment of the ESP (Injection amount and timing)? - Is it better to have more or less injection pressure? - What is the best exhaust size? Because in Germany the end of the exhaust pipe may not be directed to the right side, I should create an one tubing system. - Is there a manufacturer for tuning cams? Has someone other ideas?