Reducing road noise and loud exhaust noise

[PYLee]

Hi guys,

it seems that my exhaust has gotta abit louder from the carbon built up , had almost 1000km on it already

as it got louder, my gf and parents thinks it's abit too loud when they sit in the car so i'm thinking of a solution to reduce some of the sound.

Here are some of the product i saw online

Dynapad

Luxury Liner Pro

Your feedback is much appreciated

PS : the exhaust is awesome , have to make everyone happy thou

[LZY_EYE]

The Dynamat group buy is right down your alley!!!

If you dynamat your boot area, that should certainly reduce the exhaust noise in the cabin. Obviously the more you Dynamat, the quieter the interior will be.

[infinite]

Never! It can never be too loud! Just buy some earmuffs for the passenger seat

[ofey]

It depends really on what loudness they're pointing at. Remember that my ride is sound deadened. Significantly quieter with a stock exhaust my brother who drives a VRX claims.

Road noise can be reduced if you move away from Yokohamas. Get Pirellis or Hankooks.

As for your exhaust, don't drive without your spare. You need maybe even a full size spare to fill that hole so it doesn't act as a crevice and propagate echos from within. Before removing my exhaust, I replaced my spare inside and drove around with the GReddy and found it to be quieter than having it empty.

Plastering your car full of dynamat will minimise only ever so slightly as the other place the noise comes through is the door seals. We've got crap door seals which I have been trying to source for replacements for months!

However if you really want to give it a go, I'll say buy K&H's Spray on under body deadener and clean the bottom of the car near the exhaust then spray GENEROUSLY a layer from the bottom frame of the car. Do about 2 cans worth

Plaster liberally Dynamat on the inside of the boot and also under the passenger seat and 2 rear passenger doors.

Also buy a boot tray liner (that plastic thing) sold by Mitsu fr A$88

That's all you can do.

I suspect even after doing all of that, your parents and gf will still think it's too loud. I did ALL of that to my car and my wife still finds it too loud. Especially the "drone" she calls it on the eastern freeway. As the exhaust is constantly working at about 2500RPM. Or worse still when climbing hills in a CVT.

Don't forget that a stock exhaust works at about 78dB at 3000RPM while your GReddy is 92dB at 3000RPM. So the difference is quite large. 14dBs worth is not something your sound deadener can drown out.

[bungfritz]

Agreed With ofey on his post.

Luxury Liner Pro and stuff are good products to use as well, but if your on a budget, many people have gotten closed cell foam instead which i believe can be bought from your local clarke rubber.

Best way to go about reducing noise in the boot area would be to apply a layer of dynamat, then adding a layer of closed cell foam on top. Dynamat, strictly speaking isn't a sound absorber, but is more of a sound damper in the aspect that it reduces resonance which may come from bare metal surfaces much like a tuning fork. Closed cell foam/luxury liner on the other hand are sound absorbers which act to reduce incoming noise. Like ofey had said before, applying a layer of spray on sound deadener to the underside will also aid in reducing the exhaust drone and noise.

I've often read many people in other forums posting similar topics re aftermarket exhaust and how to reduce the noise. It might sound simple and even stupid, but i guess the best way to reduce inbound noise would be to cut it out in the first place - ie replace the exhaust back to stock.

I drive my car a lot on the highway, so for me, an exhaust is a no no as i prefer quietness on a long trip more than some extra performance gains.

[blanka]

hmmm i have a lot of road noise but its from the rims that i have on notice a big difference when i put my stokies 16s" back on the other day

[Graham]

Never! It can never be too loud! Just buy some earmuffs for the passenger seat

+1

[PYLee]

thanks for all your feedback !

lzy - i'm already in that group buy , this is a different product as its a sound deadening instead of sound damper like dynamat

infinite - maybe i could get one of those cute mink ones haha

ofey and bungfritz - when i'm on the eastern freeway, everyones fine with the drone as i'm always sitting around 1.5-2k rpm and i think the wind sound kinda overpower it at that point.

My first idea was to dynamat my whole boot , then put a layer of the sound deadening product over that wooden piece thats in between the boot carpet and the spare tyre. Maybe K&H spray on the under body as recommended by ofey.

As for the new tyres to remove road noise, i'd probably stick to this ones till i get a new set of wheels.

again , much appreciate your feedback here +1

[minimumtrade]

you need some synthetic paint-on soundproofing. The whole underbody in the boot area has absolutely none of it.

If i'ts still too noisy invest in sound proof matting that contains lead. Dynamat extreme liner i think its called

[Speedie]

Put in a louder stereo.

[SIR-VRX]

Buy a high-end Mercedes-Benz, Audi or BMW. In that order.

[bungfritz]

Buy a high-end Mercedes-Benz, Audi or BMW. In that order.

LOL you forgot Lexus, there good at creating on-road cocoons.

Anyway thought I'd interest some of you that jaycar sell some sound deadening mats which are designed to stop incoming noise. I'd give you the link but I'm on my iPhone and it's too hard lol. They'd go well ontop of a layer of dynamat in your car.

[PYLee]

yeah , family has a Lexus IS250 imported straight off japan and it's awesome

[blanka]

yeah , family has a Lexus IS250 imported straight off japan and it's awesome

oh nice those things are hot as

[tryg]

I just put in Dynamat and also did the parcel shelf mod (as per SIR-VRX and a few others). I used adhesive sound rubber on the shelf and under the boot lid, as well as Dynamat in the whole boot, under the bood lid and covering the spar under the parcel shelf.

I must submit that the difference is HUGE!

The 36sq feet supplied was enough to do the entire boot and lid (and I mean everywhere, including behind the wheel wells etc. I have enough left over to cover the two rear door inners.

Great mod guys, now my sub doesn't buzz the deck or the lid!!!!