One of the most important factors in increasing engine power is choosing the right camshaft for the type of competition you are in. Increasing the duration (and lift) allows the engine to continue breathing at higher rpm.
Since horsepower is the product of torque times rpm, this increases power. On the other hand, increasing the duration delays the intake valve closing time, which means that the piston has already risen significantly in the cylinder at that point, and the intake air partially exits the cylinder. This results in a loss of torque. This is partially offset by increasing the compression ratio, but beyond a certain delay in intake valve closing, even if a few horsepower are still gained, the loss of torque is so significant that the car is ultimately slower than with a more flexible camshaft. Also, the longer the camshaft open, the lesser low rpms remain usable. Increasing engine speed also often entails numerous additional costs: the need to use forged connecting rods and pistons, a steel flywheel, a reinforced clutch, competition valves, reinforced springs, adjustable pulleys, etc.
We are here to advise you to assemble a set of components that will allow you to build the most reliable engine possible.
