stevo1970

iTrader: (1)

I am looking for a little advice on how to make my car a little quieter. The main culprit is the exhaust noise, although it is only the prodrive system it is still boomy and could be quietened a bit. I understand its low frequency noise I need to be cutting out.

I was looking at just fitting something in the boot floor, I am not looking to improve things for the ICE so don't want to get into Dynamating.

I have trawled the archive and a couple of things have caught my attention for a cheap solution, a layer of thick carpet underlay and taking a boot carpet from another car (eg a mk 5 Escort was mentioned) are these viable solutions.

I remember my old 306 GTi-6 had a heavy underlay with a hard backing in the boot, I presume this was sound deadening, should i get something like that?

Lastly (you'll be pleased to know) is there any advantage to extending the deadening under the rear seat?

What cheap and importantly effective solutions have people come up with?

Thanks in advance.

stevo1970

iTrader: (1)

nothing?

silent running

My advice is live with it. From a sound engineering point of view, low frequencies such as booming from an exhaust are hard to cut out, and unfortunately the only effective method is sheer thickness of insulating material. Stuff like Dynamat work to a limited extent to prevent body panels from resonating along with speakers (or in your case an exhaust) but there is a limit to the amount of sound energy they can deal with. Dynamat isn't really soundproofing and it won't do what you want. Thicker boot carpet may help, and it's worth a go, but beyond that there's not much you can do. High frequencies are much easier to deal with.

nom

Fill the boot with pillows/duvets/loft insulation. Not very practical, but I find it works . I think much of the 'boom' comes from the boot space resonating, so cutting that down (the dense fluffy stuff in the boot) should improve things, and I assume also somehow blocking off the boot from the rest of the car better could help - there's nothing to do that except for the not-very-soundproof seat as far as I am aware.
It's a bit drastic but changing the exhaust manifold can get rid of a lot of the 'boom' frequencies too, or at least move them somewhere else .