I just wanted to ask if a "twin dump" downpipe with a silencer or free flow catalyser is quieter than a straight through where the waste gate is blanked off. I currently have a JSpeed one (Japanese make) I think it's similar to a HKS one. My centre section and rear box is a Blitz Nur Spec R and I was wondering if (or what) I can do to make it a little quieter?

If I wrap the downpipe with heat-insulating bandage will it also reduce noise?

Thanks

 

I think that the noise is due to the Nur Spec FAR MORE than the downpipe. A Nur Spec on my twin dump Magnex downpipe with STi/PPP resonated centre made is the loudest Scooby I have ever heard. Going back to a PPP backbox makes it the quietest decatted Scooby I have ever heard.