Shutting Up Your Exhaust Temporarily

[kiahn]

here is what i was told by the owner of an exhaust shop in ascot:

things you need:
tin snips
metal sheet
piece of wood around 20x20cm or more
drill and drill set
artliner
spanners
money

1.
you start off by measuring your exhaust noise level and comparing it to the levels specified by your state, and find out how many DB you need to drop.
each of the plates that i made take off around about 5 DB depending on the pattern you create so work out how man of these you will need to make

2.
un-bolt your rear most exhaust flange and remove the gasket, take that to an exhaust shop and get 2 new ones for every plate your making (if your gasket is in good condition you will only need 1 new one)

http://www.ae86drivingclub.com.au/dcimages/1/7/5/5/26361.jpg

3.
get a sheet of 1-2mm of tin/steel/whatever you can get your hands on and lay the gasket down on it and outline the gasket.
once this is done plot out where you are going to put the holes, i used 12mm one in middle and lots of 6mm holes around it, it dropped 8db.
REMEMBER TO NOT RESTRICT THE FLOW TOO MUCH

http://www.ae86drivingclub.com.au/dcimages/1/7/5/5/26362.jpg

4.
place the sheet down on the piece of wood and get the drill with drill bit and put your feet as close to the holes you are drilling as possible to stop the metal from pulling up.
start drilling the holes!

http://www.ae86drivingclub.com.au/dcimages/1/7/5/5/26363.jpg

5.
once all the holes are there and your happy with the pretty pattern you made get out the tin snips and cut out the plate

http://www.ae86drivingclub.com.au/dcimages/1/7/5/5/26364.jpg

6.
sandwich the plate you have just made in between the flange gaskets and put it in place and torque down those bolts

[redsprinter]

that is a awesome idea ... now why didnt i think of that instead of making a DIY slincer.

[kiahn]

if you have 1 in at the rear right before the diff it works really well, if you want another in your system i advise you have the larger holes on the outer to change the pattern and make it more effective.

DO NOT PUT ON RIGHT AFTER EXTRACTORS as they will melt unless you use higher quality steel

[Rice86]

its so simple and great...well done mate

[86coupe]

How much power do you lose by installing one of these. Is it noticeable? I'll be driving from Cairns to Brisbane and back again shortly. The exhaust gets pretty annoying on long trips like that. Was considering getting a quieter muffler for the trip, but if this does the job without causing any damage, and I can still overtake, I'll be happy.

[Rice86]

im sure you wont lose shit all in power

when upgrading exhaust from standard to something bigger wont gain anything more close to 30kw for NA anyways (just pulling random figues for example)...so restirction of the flow wont be causing it to be worse then standard i can imagine, hence why it makes it more quiet

[Matt-AE86]

It's a good idea for shutting it up but I wouldn't keep it there for a long time and they usually blow out if you try to give it stick often. It stops a lot of back pressure and can blow other gaskets and eventually upset your motor.

Good for going over a pits inspection or something for sure.

[kiahn]

yeh this is purely for engineering my car, the sound test came up at 89 dbA which is a hell of alot better than the 121 it started with before the muffler and baffle plate

the you want to make sure the hole size is no smaller than whatever is stock on your engine, so if you have a 2 inch stock exhaust then make sure you have a minimum of 2 inches of holes.
easiest way to do this is drill the holes as close as possible which will leave you with minimum restriction and maximum diffusion of the sound wave

[kiahn]

How much power do you lose by installing one of these. Is it noticeable? I'll be driving from Cairns to Brisbane and back again shortly. The exhaust gets pretty annoying on long trips like that. Was considering getting a quieter muffler for the trip, but if this does the job without causing any damage, and I can still overtake, I'll be happy.

i drove my car with it in and it it had a little more low down torque and lost a little top end up it still ran perfect and the exhaust shop guy said that it wont harm your car if you only have it in for licencing

you willl have no problem as long as you use 2 gaskets and take your time making a your plate

glad you all like it

[todd]

looks like a good idea for inspections etc.

however, this is a tried and true method for a temporary fix

http://www.briwaxwoodcare.com/images%20steel%20wool/SW%208pad--pack-a_thumb.gif

[kiahn]

but the problem with steel wool is if you get it wrong and it happens to pop out during the test you get your shit handed to you, this is a semi permanent fix and works really well and cost about as huch as steel wool just takes a little longer

[Munted]

i put 2 of these in my vr ss went from 106db to 81db lol

[kiahn]

yeh, well keep in mind that db is a logarithmic scale so the further you go down the easier it is to shut-up

[pen15]

that is a massive difference in Db i didn't know it made that much thanks for the stats im keen on making 1 now for my report

cheers

[Dazzla86]

yep steel wool an a bit of coat hanger wire an 2 holes at the end works a treat also! no need to get under the car either for the lazy man :thumbup:

[kiahn]

only problem with that is often when they do the brake test and take your car for a flog they can pop out and then they will become suspicious as to why its happened.

this is the safe and legal way to do it, someone on rollaclub said its illegal in theyre state as anything that is removable is illegal, these arent classified as illegal as they are bolted in and a part of the system.

[sundee]

looks like a good idea for inspections etc.

however, this is a tried and true method for a temporary fix

http://www.briwaxwoodcare.com/images%20steel%20wool/SW%208pad--pack-a_thumb.gif


but the problem with steel wool is if you get it wrong and it happens to pop out during the test you get your shit handed to you, this is a semi permanent fix and works really well and cost about as huch as steel wool just takes a little longer


the inpectors were onto that a long time ago.. they know all the tricks.. thought this idea seems like a good one.

good post

[ikus]

ill be doing this to pass my engineers certificate for sure! good idea.

[kiahn]

good to hear it, ive passed mine with it and now i just have to wait for the registration to pass and illl be taking it back out

[kAmbo]

lol i jammed flyscreen mesh before the muffler (packed right in). work for a bit but this is so much easier and effective!

[ikus]

just put one in, im going to the engineers in the morning. fingers crossed its quite enough!

[kiahn]

hope it works out for you, it took about 8-12 db off mine and mne is just before the over diff section, so the air gets immensly jumbled up before the rear muffler

[ikus]

cheers Kiahn, it did it averaged at 88.95 DB over the four readings. i nsw it has to be under 90 DB (not sure about other states) so just passed. yeww!