Exhaust Volume - How loud = cop bait?

[cbwolf]

Just wanting to get a few opinions.

At the moment, i have a twin 2.5" catback with the middle mufflers replaced with hotdogs using tri-y extractors and 2.5" metallic cats.

It's pretty loud as it is, at an estimate 100 - 110db at idle.

I'v ordered a cam from Texas Speed, 231 234 111LSA, so it's pretty chunky and will have a very rough idle. I'll also be fitting a twin 3" x-force exhaust to the car when the cam goes in.

So just wondering, is this going to be obnoxiously loud? So far, i haven't had any issued at booze-buses or when pulled over by police in regards to noise, but i'm worried this will be too loud to overlook for the police officer.

Any ideas?

[michaels1v8]

Umm 100-110db at idle?
:eyes:

Get a muffler put in that is insane!

[Knawful]

EPA Victoria:
Noise level Before: Passenger vehicle (Other than a bus)
up to 1 November 1983 96 dB
After 1 November 1983 90 dB

See Page 10 (http://epanote2.epa.vic.gov.au/EPA/Publications.nsf/2f1c2625731746aa4a256ce90001cbb5/c90ec843f3bbbe8fca256d9f00181c59/$FILE/1031.pdf)

So yeah..Loud (on road) = bad mmmkay

[cbwolf]

Ok you guys do realize that a simple twin 2.5" cat back with no high flow cats and no extractors will get around the 95db yes?

The majority of people on this forum would range between 100 - 110db if they have a full exhaust system.

[ova400]

I currently have a sureflow extra loud 3.5" exhaust and have never had trouble with the cops. There seems to be plenty of people with 3" X forces and cams in the 230's so you should be able to get away with it, but all it takes is for one copper in a bad mood and you'll be done, but its that way already as is, just a bit less noticable

[mustanger]

Lets just say that the legal limit @ 90 db is very quiet,infact way too quiet. If you change your exhaust,I think the trick is, not to give it WOT in built up areas ,as it draws attention.

You will be surprised , most Police Officers will turn a blind eye , as long as you are not being a Hoon :teach:

[michaels1v8]

Ok you guys do realize that a simple twin 2.5" cat back with no high flow cats and no extractors will get around the 95db yes?

The majority of people on this forum would range between 100 - 110db if they have a full exhaust system.

Yeah I realise that but at idle?:confused:

If thats what your pulling at idle then your system would be insane at 75% of the redline (I think thats what was decided to be about the RPM for noise tests). I was under the impression most systems would be around 100db at 75% of redline

But yours is more than this at idle so:bow: but that is insanely loud

[GMMAD]

its isnt very loud at idle but when you get on the gas it will be loud

[Mad4Monaros]

Lets just say that the legal limit @ 90 db is very quiet,infact way too quiet. If you change your exhaust,I think the trick is, not to give it WOT in built up areas ,as it draws attention.

You will be surprised , most Police Officers will turn a blind eye , as long as you are not being a Hoon :teach:



Agreed 100%. If your not being silly they will leave you alone.

[SICK SS]

^^^^^^^^^
thats not true. And i highly dought your exhaust is between 100 db-110 at idol unless ti was runing straight out of the block

[mickeyVX350]

Hehe.. My SS is a little loud I think... but not B&S Kingswood loud! It has a 2.5" exhaust with Mid muffler and straight through pipe.

I drive past the police station every day, just don't stand on the throttle.

[[Mitch]]

Difilippo 4into1s, 3" cats and twin 3" X-Force system.

121db at 4500rpm.

Been defected for it but the cops border on harassment around here.

Sounds awesome, i absolutely love my x-force system but you really have to idle around to keep it quiet.

[ADAM 26]

iv got a 232/234 cam and cnc ported heads and im running a x force twin 3 inch system, its pretty loud, not sure of the actual reading tho. i was driving next to a mate a trompped on the throttle and he said his ears were ringing for about 15 mins after. so im guessing its over the limit.

got pulled over the other day, and the cop didnt say anything about the exhaust note being to loud, or anything about it being lumpy?? not sure why, its pretty obvious, so he just done me for too low! no roadworthy req either!!

[C4B]

110db at idle...... :lmao:

[SV346]

wow i didnt think a twin 3 full system would be 120ish decis! good stuff :) Ive got a full twin 3 with only 2 hot dogs, 1 3/4headers n that and yeah its loud when you stomp it, i think its quiet otherwise but i get told the other. :smilesandbanana: My neighbours are very kind and tolerant to my love of noise fortunately, they are great people. I also do find that unless you are booting it cops dont really pay that much attention at all to it.

[Mad4Monaros]

^^^^^^^^^
thats not true. And i highly dought your exhaust is between 100 db-110 at idol unless ti was runing straight out of the block


I agreed with the term "most". Not all.

[VXSS346]

Does anyone actually realise how loud 110-120db is??

Dreamers!!! :lol:

110db at idle?? :lmao:
121db at 4500rpm?? :lmao:

I think not. :)

My 2c.

[SICK SS]

Does anyone actually realise how loud 110-120db is??

Dreamers!!! :lol:

110db at idle?? :lmao:
121db at 4500rpm?? :lmao:

I think not. :)

My 2c.

isnt a jumbo jet taking off measure a db reading off 115/120 db from 100 meters away

[alakasam]

Decibels follow a exponential progression, not a linear one.


Sound Environment Sound Pressure Level (dBA SPL) Approximate loudness with regard to ordinary conversation
Threshold of hearing 0, Don’t hear anything
Broadcast studio interior or rustling leaves 10, 1/32nd as loud as conversation
Quiet house interior or rural nighttime 20, 1/16th as loud
Quiet office interior or watch ticking 30, 1/8th as loud
Quiet rural area or small theater 40, 1/4th as loud
Quiet suburban area or dishwasher in next room 50, 1/2 as loud
Office interior or ordinary conversation 60, Ordinary Conversation
Vacuum cleaner at 10 ft. 70, Twice as loud
Passing car at 10 ft. or garbage disposal at 3 ft 80, 4 times as loud
Passing bus or truck at 10 ft. or food blender at 3 ft. 90, 8 times as loud
Passing subway train at 10 ft. or gas lawn mower at 3 ft. 100, 16 times as loud
Night club with band playing 110, 32 times as loud
Threshold of pain 120, 64 times as loud as conversation (twice as loud as night club)

http://trace.wisc.edu/docs/2004-About-dB/

[Knawful]

You guy's DO realise that just 'cos it's louder, it dont neccasarily (sp?) make it faster yeah?

[cbwolf]

Decibels follow a exponential progression, not a linear one.



http://trace.wisc.edu/docs/2004-About-dB/


Actually it's logarithmic, not exponential, and whilst a reading of 3dB takes double the energy to produce, it takes an increase of 10dB to "appear" twice as loud.

So a stock Clubsport exhaust, which has been generally found to produce around the 90 - 91dB mark (i beleive it's tested at 3000RPM @ 1m) is pretty quite.

[BLACK 346]

You guy's DO realise that just 'cos it's louder, it dont neccasarily (sp?) make it faster yeah?

Doesn't necessarily mean it sounds better either.

[[Mitch]]

Feel free to come and listen..

No one said anything about a louder being faster.

A question was asked and i gave an answer.

X-Force twin 3" with extractors is very very loud, simple!


Doesn't necessarily mean it sounds better either.

That comes down to personal preference.

[Wonky]

Does anyone actually realise how loud 110-120db is??

Dreamers!!! :lol:

110db at idle?? :lmao:
121db at 4500rpm?? :lmao:

I think not. :)

My 2c.

Actually, back in the mid 70s I had a cammed EH with head work, extractors and twin pipes, one out each side just in front of the rear wheels and with only a hot dog on each. It literally screamed at high revs! :shock:

I was pulled over around Blackburn one day by an EPA guy (or whatever they were called in those days). He told me it measured 124dB (though that was at high revs). Maybe he was BSing me but that's what he said!

[BLACK 346]

X-Force twin 3" with extractors is very very loud, simple!

Yeah, have heard the twin 3 with extractors, start talking cammed
cars and then we will talk loud :)


That comes down to personal preference.

True, was just saying that making it louder does not necessarily
improve a shite note, not saying it cant be loud and sound nice:)

[tanka5.7]

i got pinged by the epa in my vx with tri y's twin 2 &1/2 exhaust with no resi and high flow cats and it measured 104db at 3600rpm i measured it with resi and it was 93db

[TAKEITEZ]

i have a pretty basic DB meter here... i think i should test mine... i don't think its loud - as its not that bad when you're driving it...
but i've had people say its massively loud...???

anyway... my motto with loud/lumpy/angry cars... or slammed and blinged cars is.... "its not what you drive, its how you drive"

a cop generally won't give you trouble unless you do something to give them half a reason to pull you up...


i have pacey Tri-Y's, stainless 4" cats, twin 2.5 sureflo "medium" with rear resonators removed...
my ute was tucking tyre front and rear, measured 58mm ground clearance at the lowest point, 97mm the whole length of the side skirt... (since been raised to stock + SL rears)

i would go into town and burble around taking off locked in 2nd, letting it pull 3rd as quick as it could, and never exceding 40kph in the city (50 zone) and you could drive next to cops, in front of cops, behind them, and never have a problem...
old mate comes up in a stock 1994 corolla hatch and gets nailed because he accelerates too quickly from the lights when next to you ;)

[Demon76]

i tend to agree with the comment about cops not bothering you unless you give them a reason too. I was pulled over once in one of my turbo cars which a straight thru exhaust, (no mufflers at all) and some big cams (along with a whole heap of other mods) and the police officer did not mention the exhaust noise at all. I still don't even know why he pulled me over. When I asked him why he had stopped me, he said that I edged over 60kpm. He had a look over my car, asked me some questions, we got talking about cars and bikes and then he let me go. If you are pulled over and you act maturely, they tend to be ok and let you go...that's just my experience though.

[iloveholden]

My dad had a HZ GTS with had header work, extractors and full straight through exhaust with existing twin pipes.

To give you an indication of how loud it was, even without WOT you could here every gear change for about 5km away, sounded sensational.

Louder doesnt mean faster but the sound is simply sexy.:bow:

[raji2]

[, start talking cammedcars and then we will talk loud :)

True, was just saying that making it louder does not necessarily
improve a shite note, not saying it cant be loud and sound nice:)[/QUOTE]

I cammed my Vy on the weekend and can not beleive how much louder it is. 2.5" diffilipo with extractors sounds good. Even though mine looks totally stock I'm going to quieten it down as I'm past being cop bait. Been there done that and it wasn't fun!!

[VYSHSV8]

Cam and 1 3/4 d'fillipos twin 3" cats and twin 2 1/2 d'fillipo cat back no rear resy
sounds like this through my digital camera/ not vid camera

http://i6.photobucket.com/albums/y243/VYSHSV8/VYSHSV8/th_VYSHSV803.jpg (http://s6.photobucket.com/albums/y243/VYSHSV8/VYSHSV8/?action=view&current=VYSHSV803.flv)

[Oldmate83]

Haha thats heaps loud, what do you think makes the bigger difference in volume, the cam or the extractors?

[BLACK 346]

Haha thats heaps loud, what do you think makes the bigger difference in volume, the cam or the extractors?

Cam makes a much bigger difference to volume and note compared
to headers :)

[klink]

Haha thats heaps loud, what do you think makes the bigger difference in volume, the cam or the extractors?

I would say the cats would be playing a big part in it, having recently replaced the stock cats with 3inch metal sub cats.

[Wonky]

Haha thats heaps loud, what do you think makes the bigger difference in volume, the cam or the extractors?

Having heard it in person I can tell you the video does it no justice!! It is faaaaaarken loud!! :yup:

[seldo]

Actually it's logarithmic, not exponential, and whilst a reading of 3dB takes double the energy to produce, it takes an increase of 10dB to "appear" twice as loud.

So a stock Clubsport exhaust, which has been generally found to produce around the 90 - 91dB mark (i beleive it's tested at 3000RPM @ 1m) is pretty quite.
It is logarithmic , not exponential, but it may as well be.... For example - the 10db difference between 90db and 100db is not 10/90ths louder - it's 10 times as loud, and 100 to 110 is 100 times as loud again! Distance however, works almost the opposite - the sound diminishes in inverse square relationship, so that as the distance from the source doubles (increased by a factor of 2) , the sound quarters (decreases by a factor of 4). So, I'm afraid that some of these blokes claiming 120+db are in fairy land - that's approaching the threshold of pain.
This gives you a bit of an idea:
Source.....................Intensity Level.... # of Times Greater Than TOH
Threshold of Hearing (TOH),......... 0 dB..............10*0
Rustling Leaves..........................10 dB..............10*1
Whisper....................................20 dB..............10*2
Normal Conversation....................60 dB..............10*6
Busy Street Traffic......................70 dB..............10*7
Vacuum Cleaner..........................80 dB..............10*8
Large Orchestra..........................98 dB..............10*9.8
Walkman at Maximum Level..........100 dB.............10*10
Front Rows of Rock Concert.........110 dB.............10*11
Threshold of Pain.......................130 dB.............10*13
Military Jet Takeoff.....................140 dB.............10*14
Instant Perforation of Eardrum......160 dB.............10*16

See http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/sound/u11l2b.html

[SICK SS]

Cam makes a much bigger difference to volume and note compared
to headers :)

no ressonator makes a big difference to

[NefariousLS1]

guess the other day straigt out the cats bored on the way to work at about 4500 rpm in an auto going past a cop going the other way may have gotten his attn lol

[ignitionthunder]

just tested my twin 3" x force exhaust. 91db at 5500rpm.

[iloveholden]

Cam and 1 3/4 d'fillipos twin 3" cats and twin 2 1/2 d'fillipo cat back no rear resy
sounds like this through my digital camera/ not vid camera

http://i6.photobucket.com/albums/y243/VYSHSV8/VYSHSV8/th_VYSHSV803.jpg (http://s6.photobucket.com/albums/y243/VYSHSV8/VYSHSV8/?action=view&current=VYSHSV803.flv)

That sounds very nice mate, its seems pretty loud on camera so it must be loud in real life?!

[Wonky]

That sounds very nice mate, its seems pretty loud on camera so it must be loud in real life?!

Sure is - see post #35. :)

[Oldmate83]

My ls1 sounds like S*** with the current cat-back, hopefully headers will make some improvement (not just louder, but not so much like a 4cyl)

[6LS2]

Where can you get your exhaust tested to see how loud it is?

Want to get my dads VZ Clubby tested, fark its loud :)

vids

YouTube - VZ Clubby exhaust

YouTube - VZ Clubby 2

[Wonky]

Where can you get your exhaust tested to see how loud it is?

Want to get my dads VZ Clubby tested, fark its loud :)

vids

http://www.youtube.com/watch?v=8lK_6fdBda4&feature=user

http://www.youtube.com/watch?v=41Tw7-LpAXI&feature=user

I don't think I want to know mine....... :D

YouTube - Wonky's KPM System (Short)

[SSV8TE]

Gday all,
Going on the vid posts here as you all know horsepower is voiced by the type of note coming out back not the volume of note. Play with the mufflers untill you get that sweet sound but not too loud. WOT sounds grouse on these chevs loud or quiet. Spend money gettin kw's not decibels.
Cheers,
Andy.:)

[JT]

EPA test on ls1 is at 3900 rpm, meter 30cm from outlet at 30 degree angle

[6LS2]

I don't think I want to know mine....... :D

http://www.youtube.com/watch?v=89Y2yWve8QE


Ive heard yours in real life, my old mans is much louder.

[Wonky]

Ive heard yours in real life, my old mans is much louder.

In that case I wouldn't want to be driving it. :D It's always hard to tell from a video how loud it really is. I saw VYHSV8's driveby video before I went to WA then heard it while I was there. It was much louder in real life than it sounded on the clip.

[vystormboy]

I'm looking at hopefully getting and exhaust in the next couple of weeks for my VY storm...
i wouldn't have a clue what to get but i hear either xforce and df are the ones to look at..
also i heard abit about redback, has anyone had any bad experiences with these?
also what actual system would be the best for a ute?
And any ideas on a price?

[Wonky]

Do searches on X-force (Xforce) and Redback on here (Search tab, top right of page) and you'll find plenty of reading on each as each has been discussed in detail plenty of times before.

[Clubb'N]

My dad had a HZ GTS with had header work, extractors and full straight through exhaust with existing twin pipes.

To give you an indication of how loud it was, even without WOT you could here every gear change for about 5km away, sounded sensational.

Louder doesnt mean faster but the sound is simply sexy.:bow:

;) I had a HZ GTS myself, cammed 308 with head work, tri-y's straight thru muffler ... erm, fell off at the diff ... oh that thing purred at idle, loped nicely, shook windows and at WOT well ... on a nice night ... people could hear me ten minutes away :D
EPA didnt like it though :(
Was also slow :(
lol