Sigh. Ok discodickhead. Please go search a little subject involving pressure difference between exhaust manifold and inlet manifold. Then, after you get your puny brain around that, search the next subject. Exhaust scavenge, velocity and pressure balance vs flow dynamic properties of hot gas. There is a reason the most obvious of all machines, trucks, use large bore exhausts that are short, smooth and free flowing. I know that in most cases, the turbocharger is designed specifically for a particular engine capacity and configuration as not having a responsive boost control method on the exhaust housing may blow your mind, but the theory is exactly the same. The pressure difference between the inlet and exhaust manifolds need to be different, the less pressure in the exhaust manifold, the faster the turbocharger can compress, therefore fill the cylinder and in turn, increasing performance and most importantly, response. The more air you can get in, the more air you can burn and get out. Next subject will really rattle you. Volumetric efficiency. Actually, fcuk it. Your a deadset spastic. Just google shart. That's about what your good for.