Having recently purchased a Zafira Gsi, I have started the modification process in an attempt to make me feel less unhappy about having to let my coupe turbo go. I loved the exhaust I had on the coupe so went for an identical set up on the Gsi plus the addition of a pre-cat pipe.
Even with a centre silencer built in, it seems so much louder than the system on my coupe. I have heard rumours that fitting a pre-cat will make a system louder, and can change tone higher up the revs - is this the case?
It seems quite boomy up to around 3-3.5k RPM, then gets higher and rather tinny like an M3. Has anyone else noticed this?
Is it worth getting a larger centre silencer fitted, or is it just a case of putting up with it after fitting a pre-cat?