Hi guys , a little help if you guys wouldn't mind please.
I have an aftermarket exhaust on my car and boy is it loud ! Changing it isn't an option. So I was wondering if anyone has any ideas about sound proofing the car.
What material would be best and where to get it from and how much
regards

sean👍🤞🙂

 

You could put "Silent Coat" in the boot floor and transmission tunnel.

They make different types of product depending on how it will be used, just google. It's pretty effective in my opinion.

 

Hey Matt

thanks for the suggestion mate I really do appreciate it. What thickness have you used? I dont mind the sound, its what gives in my opinion the car that extra bit of appeal for me. But occasionally you do think f_/kin hell ! ��

 

 

 

 

Hey Matt

I live in oxford and was looking on silent coat website for a contact number and just so happen to see they are based in oxford too, so I will call them tomorrow to see what they can recommend.
I'm looking to reduce the noise in side the car as much as possible , if possible all

 

 

Mate I hope it does !�� so you reckon the 2mm will do the job?
What you driving at the min ?

 

 

What on gods green earth are you driving �� lol a total beast by the sounds of it ��
them monaros... boy !! they are something else, they are crazy times the car is clocking.
What made you go for one of those ? We have a cpl of them going around by us , as far as sound goes it makes mine look like a little kitten even in a straight line most probably.
lol I bet she started off with it was your fault until you pointed to the dash cam, was the damage bad ?
As far as mid section goes I don't want to lose any power, i actually don't mind it but we have a little one who likes going in the car and I don't want to damage the poor guys ears lol

 

May I recommend a set of ear defenders...

Seriously, I have stripped my Hawkeye out and put the proper Dynamat in the roof, floor tunnel and all doors and rear wings, etc. Basically everywhere. The result is that I can confirm it's basically a waste of time.

The road noise of a stiff O.E. 17" tyred Impreza NewAge comes in far too loud still via the thin glass windows. You can't escape it. I have amazing ICE, and need to be parked up engine off to enjoy it, and that's with a STANDARD exhaust fitted.

If you have a loud pipe. I'd go down the intercom route and a pair of BOSE noise cancelling headphones...

 

The maloo is a bit of a beast , it’s a pick up that goes through the aussie version of amg , wheel spin at 80 mph in the wet it’s quick off the mark and very loud , 7500£ worth of damage , she pulled out and spun me out so a lot of suspension related damage wheels are 20 inch with a 275 profile so wheels and tyre knackered plus expensive , brakes are unbelievable it slows down lifts you out of your seat , highest bhp in the club is a 6 litre v8 twin turbo pushing out 1200 bhp , a supercharged version of mine puts out 630 bhp easily ,on a drag strip with drag tyres it’s around 3 seconds to 60’its all about grip , but downside with that much power it’s not as drivesble , funny thing is you can drain a 75 litre tank in 63 miles or average 35 mpg , a very small silencer will have a minimal effect on power and probably reduce noise by around 20 per cent , good flow and more noise are sort of hand in hand , the Fsti got that to 164 mph on a track day at Marham it’s getting on now so i bought another , quick plus good mpg , i like both cars for different reasons , lots more torque and bhp plus noise in the v8 but scoobys are great all rounders , sound deadening is the cheapest option so try that , if not enough then a small silencer the ones that look like the old cherry bombs and noise will reduce , when i did a delete centre section on the fsti it was a very minimal change just felt like it flowed better

 

 

 

Plus try much narrower tyres!

 

Silent Coat and similar products are designed to reduce vibration/resonance of metal panels. Simply fitting them on their own will not greatly reduce "noise" - they will stop certain frequency vibrations and trim rattles. They also add weight to panels, which is why they are essential for any ICE installation, with the added bonus that your doors will now close with the reassuring thunk of an 80's Merc.

To actually reduce cabin noise by a considerable & noticeable amount, you need to use Mass Loaded Vinyl (MLV). It comes as a dense roll of vinyl rubber and acts as a barrier to block sound. At a minimum it should be applied to the floor of a vehicle as the majority of noise is reflected off the road and through the floor. In order to be as effective as possible, you should look to cover as much of the floor as possible. It should be noted that MLV & other barriers should not be in direct contact with any hard surface. Closed Cell Foam (CCF) should be used decouple or separate Mass Loaded Vinyl from the vehicle. So you should look to use a 3 layer system of Isolator (Silent Coat etc), Decoupler (CCF) and Barrier (MLV) on top.

You don't need to go crazy with the Isolator; 25% coverage of an area will give good results and it's diminishing returns after 50% of panel coverage. CCF & MLV layers however should cover the entire area wherever possible. Maybe consider just doing the boot floor first and see whether that suffice. Problem is that the door panels on Impreza'a are also very thin so you are starting from a poor position already.

 

@ Matt 7500 �� !!! That is some damage , but in regards to the numbers you mentioned for the cars that is something special.
How long will the beast be off the road for ?

 

Tech
thanks for the additional info , so the with MLV & CCF what mm should you be looking at inorder to make some real impact ? Even with the silent coat

 

Just wondering how would norrow tyres help ?

 

5kg/sq.m density minimum for the MLV. Some is 2mm other 8mm + You don't want it too thick as you need it to be flexible enough to mould to the shape of the floor/boot. Probably 10mm+ for the CCF but some products will work also which are much thinner.

https://www.dodomat.com/ are a well used UK company but you can get decent results using cheaper, non-automotive products, if you do a thorough job installing it.

 

Hey tech
In what order do you suggest the insulation be applied ? I will try get on to it as soon as possible.
The MLV I looked yesterday came in 3mm

 

Did you go ahead with this.

 

Some really good advice on this thread from people with experience.

FWIW I also found soundproofing my second Impreza (classic) in 2002 a bit of a waste of time as the gains were marginal, so I haven't bothered with the one I have now despite spending a lot in other areas.

Looking back, the best result I had with soundproofing a comparably built car was a late mk1 RAV4. I laid jute material under all the carpets and rear seats and put dynamat type stick on sheets around the rear wheel arches and boot wheel well and floor. It made a big difference to road noise, especially in the wet, but the car was still loud through the engine and glass. Underbonnet soundproofing didnt really work as layering the bonnet didnt stop noise travelling through the bulkhead.

 

Sorry I didn't reply to the July post - must have missed it!

As per my earlier post: "So you should look to use a 3 layer system of Isolator (Silent Coat etc), Decoupler (CCF) and Barrier (MLV) on top." Apply in that order.

It's a bit all or nothing. The floor is the biggest issue as the majority of noise is that reflected off the road and through the floor of the car. But then you have engine noise coming through the bulk head and then also through the glass as mentioned. I'd probably not attempt to achieve this in an Impreza, given the additional weight and it's supposed to be a sports car after all! But on a big GT car or saloon where you are just cruising, then it would be worth the effort.

All the work I have done on my Imprezas has been to reduce vibration which greatly effected the quality of my audio install (so sound deadening the doors so that the speakers work efficiently) and then to reduce vibration in other panels caused by the speakers/amp install (floor, rear boot lid, rear doors, door trim etc). As opposed to actually trying to reduce NVH caused by driving.