Paulyy

I've just bought a SS 3" with 5" barrel, 18" long with SS baffling. i'll pick that up tomorrow and hope for the best. if that doesn't work, i'll somehow modify the stock muffler/catback to work with the 3" turbo back and hope for the best.

95ONE

Great information!

Black51

Just stick a potato in it for now. That'll shut it up.

Paulyy

well i cut and clamped a new muffler in, sounds much quieter, but because it's clamped, it has a small leaks which i'll weld it up next week. if it doesn't pass when i take it tomorrow, i'll fab up some sort of 2" restrictor/ silencer that i'll just stick into the exhaust which should work.

911-32

^^^^ exactly. If you just need to pass the test then you can restrict the outlet with a removable "bung" which you can also wrap in glass wadding etc. We use this trick to get thru static noise tests at tracks all the time on our 911s. As soon as we have the sticker showing a pass, its back to the pits and remove the bung and run it wide open. I would guess that you need a only temporary solution, yes? I have run my 911 with one side of a 2-out muffler completely capped and the other pipe with a bung and a big fist full of wadding stuffed behind that. Yes, it kills the flow, but it only for a test.

Cyberpunky

down here you really need a permanent cure as our cops have gone hi tech and now keep active records on cars. If a car got defected ppl would change it to get it passed and then changed back after test, but now photos are taken of rectifacations, and if the cops find you have changed back the fines go up astronomically from hundreds to $10000 ish with other penalties. The cops have light meters to test tinting, laser temp gauges to check if cat has been removed, and a on board computer system that they can view pics of rectification work. The days of doing dodgy mods to your car are gone here
peace
Cyberpunky

911-32

Wow - Australian cops are outrageous.

Even worse than NZ !

brrgrr

I have a stock muffler section modified to fit my 3" SFR exhaust - No cat, no resonater - and it sounds very close to stock - no booming and would certainly pass the noise test. The stock muffler is 2.5" dia. straight thru and I would wager only reduces HP by 1-2 %. If I swap in my Borla Bullet 3" muffler it is extremely loud.

Since I may be moving to Australia I need a little education - what the heck is a "hot dog" when you are referring to the exhaust of a car ????

Paulyy

after driving it, the muffler actually sounds real nice and smooth. im enjoying the deep perr it makes.


If i need to get that extra few dbs i'll be doing that!

Dam straight they're that bad. gladly, mine being originally ran on Leaded fuel, by law i don't need to fit a cat.
the window tint device is crazy!, a female friend of mine, she want's to get her windows tinted 1 shade from legal so ilegal.. im begging her not to do it as i know she'll get in trouble as her car does bring attention.

Gotta admit, some police aren't that bright when it comes to modifications.
for the first time i got asked to pop the bonnet (that night when operation hotrod took place) and he was in for quite a shock.
when i lifted it, his face literally lit up and thought what the f*ck is going on under here..
he finds my intercooler and asked "um is that an intercooler" and i responded "no, that's just a larger oil cooler/radiator to help keep the temps down on the track"
he's like ahh okay..
then looking at my intercooler pipes and figuring out what they are and where they go, by this stage he was quite confused and asked me if it's turbo. i responded by saying nah it's not, if you have a look here -pointing to the exhaust manifold (where most turbos are located)- it's just an exhaust manifold straight to the exhaust. he said yeah, if it was a turbo the turbo timer would have been on before you turned off the car.
Then he got more confused when he looked at my cone filter and why it wasn't connected straight to the intake manifold... he actually looked how it was connected for a good 2-3 min with his torch.

Good bloke though, told me to drive safe

It's called operation hotrod. been pulled over 3 times in 2 weeks with no suprised

by going back to a 2.5" muffer is like having a 2.5" exhaust all the way until the end of the 2.5" muffler. so it's probably robbing more then 1-2% of hp might be somewhere between 5-20 hp depends on boost ect..

a hotdog is a glass pack really.

Thom

Better never take the **** at the police, while they may appear clueless they may be testing you...

Paulyy

i usually keep my mouth shut until they ask questions. when they ask if it's a 928, you know they dont know whats going on under there though..

went to the RTA today and told me that i needed to go somewhere else to get a certificate of my db readings.. ehhh this is not what they told me when i called them up.

so i used my iphone and got a reading of 89db @4k rpm which is 1db under the limit. i made some sort of baffle and put it in my exhaust near the tip which acts like a restrictor which is a plate with holes in it. i got a reading of 88db in a warehouse (which echos) and lost so much power. 10psi at 4krpm... from 18psi at 3500
tomorrow i'm booking in a test and hoping for the best.

Cyberpunky

You need to go to any exhaust place that is a licensed EPA tester. I had a cop follow me, in my old corolla for about 20 seconds and then he then pulled over, leaving me alone. I got the *notification* in the mail and had to get my system tested. My car was pre-74 so is legal up to 95 dB but when I rocked up to exhaust place the guy laughed and said no way was my car even close to the post 74 92 dB. He tested it and it was 89 dB, which was 6dB under what I was allowed to be. When the cop heard my car it was still cold and so a little louder than normal but the corolla is a quiet car. It has a custom 2" system, with extractors, a hot dog and large muffler. The guy who built it wanted to make it loud but I insisted he make at quiet as possible without compromising power.

As every 3dB is literally a doubling of loudness, I was half the loudness of a modern cars maximum loudness and a quarter of what I was legally aloud to be. whole thing was a joke and they don't even give you a refund on the test when you pass with flying colours. I always kept a copy of test just in case another cop wanted to waste my hard earned.

I was surprised when you said you had to present your car to RTA Pauly, but figured they had changed the testing requirements. Last thing you want is cops making you run your car over the pits at RTA, as those guys won't miss anything
peace
Cyberpunky

Paulyy

That's a good idea, my mates say my car is now very quiet so i hope is passes, the baffle makes it even quieter. I'm going go keep the pass sheet with me so if the cops so get on my nerves i'll just show them the sheet..

my instructions where from the cop who got me at the time was "fix it, and show vicroads you fixed it" no where he said to take it to an exhaust shop to get a certificate with the db level.

If i took my car to the pits.. well that's another story.

Paulyy

came back with the results... tested by a proper EPA tester my exhaust is 98db so 8db to loud

he said to call him monday to work something out, either i'll get my catback to fit for the test or he might write me up a pass.. because all i need to do is hand in the sheets at the RTA saying i passed

thingo

How exactly did they measure it, ie where was the mic and is that at idle ?