the manifold is the main part of the exhaust system that restricts the flow, the standard kit is a real bottle neck as it meets the exhaust
The manifold is a good
mod to do, it really will free up your car, and having seen Dunc shift the way he does (nothing to do with his linen suits) it is well worth it.
Oh and if you want a proper system, suggest you check out PlayMINI, unless you like the look of tin and scaffolding
