Hi,

I am nowhere near the point of making my exhaust yet, but wondered what people's opinions were.


I'm running a Fiat 5cylinder turbo and plan a side exit exhaust, I was wondering if a sports cat as my only silencer would a) pass the IVA (although I will be on a Q plate.. so shouldn't need a cat?) and b) how loud will it be?

I want it loud, but will it be too loud for track days. I'm planning on building the zorst from 3" stainless tube, it will be pretty short as it will come off the turbo at the front of the engine and down out through the side in front of the passenger side.

Rob

I doubt you will pass with sports cat only. I have 3" pipe turbo back to 3" sports cat and then a silencer of motorbike style (ie. straight through perforated tube with fibreglass packing wrapped around it) silencer is 3" entry and 2.5" exit. Failed IVA for it among other things although it was close and was able to pass with a decibel killer in it.

Cool, what Engine are you running??

I was thinking the cat could be the tail pipe? It would be exiting the body work if that makes sense, so the exhaust system would have to be inboard, i.e. In the engine bay.

It'll be too loud for track days unless the cat is hugely restrictive. I ran mine with a 3" pipe straight off the turbo for a while, but it was horribly loud and didn't even sound that good. I've since added a bike silencer (R1 can reworked to have a 3" perforated pipe wrapped in wadding), and it's still way too noisy for anything other than 105dB trackdays.

I'm about to build a 30" long 7" dia can to try to get it down to 95dB.

Engine is a 2l Zetec turbo.

[Edited on 20/7/17 by djtom]