I collecting parts for spring engine overhaul. At the moment, I am bothered by the choice of cat. A few years ago I replaced the complete exhaust. Then I try to chose something that would not be noisy. It turned out that it was quite noisy at speeds of 120 -140 km h ; it's just boring and pointless to me Does anyone know how much the noise would increase in case I install a sports catalyst? Noise coming from the engine compartment in that case ? The limitations are known to me. i think about 280hp is possible. Exhaust pipe is 70mm from cat to the end . + turbo from mk3 . The car is not for the track. There is simply no good track around my location .
