45 replies to this topic

[LXCHEV]

I would like to bring up the good old topic of muffler choice! I was cruising around in the LX the other night and got pulled over - whilst the two coppers were really nice and seemed to love the torry, they said it was just too darn loud and that I can now expect a letter from the EPA (Oh Joy!!!)

Soooooo, it's time to quieten her down a bit. Regardless of my upcoming noise test, I've wanted to quieten it down a bit anyway. It is too noisy for cruising the streets, I'm always paranoid cos of how loud it is, especially driving it at night, if you open her up it shatters the night time silence and you know people will hear it literally km's away. Plus it's gotta irritate the neighbours, particularly on those early morning starts for car shows etc....

My current mufflers are Supercat straight-through's (but with an expansion chamber in the middle). It's a twin 2.5" system the whole way (Chev 383 V8 with Tri-Y's). I recently also had a 10" resonator welded into each bank before the mufflers.

My plan is to remove these mufflers and replace them with a good quality triple flow. So what options do I have? I'd like something that will take some noise out, but not be overly restrictive (is there such a thing?). Obviously, I want them to sound good too. Anyone have any good suggestions?

And also, what are your thoughts on performance/HP loss by switching to a triple flow after running straight-through's??? Would it really sob that much???

Any thoughts and ideas would be much appreciated!

Thanks all.

[gtrboyy]

Do they still sell those supertrap mufflers with the spin-on discs,you can use all the discs to quieten/strangle the car or take them all off for a proper straight through effect & a lot less restriction.

[makka]

ahh Brett, the EPA again!

I am running some offset in centre out mufflers (supercat I think) and they sound good and are not too loud. I take it yours are centre in centre out?

[LS1LX]

With my motor, running 1 5/8" extractors into 2 1/2" collectors, twin 2 1/2" system running the full length of the car over the diff, I have 2 tiny Hi-Flo cats smallest available and 2 Borla PRO XS mufflers, offset in/centre out.

Idle noise tested 86Db at tailpipes.
Don't know how loud you can have it in Vic. But 86Db is what mine is ment to be at 4,500rpm not idle. (3/4 of peak power rpm is were its measured)

Edited by LS1LX, 21 June 2006 - 07:37 AM.

[LXCHEV]

Liam, hahaha what can I say mate except that great minds think alike! What happened when you got your 'warning' ???

makka - I believe my current mufflers are an offset style straight-through (with a chamber in the middle). To shut the chev up a significant amount, it's going to need a much more restrictive muffler I believe.

1QUICKLJ - The Walker Dynomax turbo's you mentioned - they are Lukey right? Would this be them?....

http://www.lukey.com...=CONTENT&sid=64

Nothing on the site for the link above actually describes the internal design of that muffler, I assume it is a tradtional triple flow type design (ie. up, back, up again)...
Thanks for the other suggestions too, I will look them up next.... but have thinking of possibly trying some Lukey's.

LS1LX - thanks for the info too - WOW 86dB is super quiet! In Vic we are allowed 96dB, and my car is WAAAAAY over that. You're running an injected motor right, maybe that's half the reason why you've been able to get yours down so far. Will suss out those Borla mufflers though too...

Cheers all, keep the comments coming!

[LXCHEV]

D'oh, that above link didn't go where I wanted it to. Just click 'Products' and then 'Turbo Muffler'....

[LXCHEV]

Whoops, yeah 86dB at idle is loud, I misread that & didn't twig that was at idle.

Thanks for the other link too, will have read of it when I get a chance.

As for the glasspacking - I thought our Supercats were glass-pack too???? Maybe not....

One bloke I spoke with today said he likes the Redback triple flows - said they would be a lot quieter, but still good on performance. And they are one of the better flowing triple flows around...

The research continues... I think I'm going to buy myself a dB meter from Dick Smith. Even if it's not dead-accurate, it will give a good indication, then I can play around

[LXCHEV]

Yeah a few people keep suggesting the Hooker mufflers. I found a pic of what they look like on the inside:

http://www.vpw.com.a...6&PrdGrpID=2781

Might call VPW tomorrow and get some info on them. Are they a quiet muffler? I reckon they would still make a fair bit of noise???

[LS1LX]

Yeah old cars are 96Db at 3/4 rpm, but my engine is ment to be 86Db as its 2001 model engine.

[MRLXSS]

Interesting topic.... I have heard good things about Redbacks..

Are you looking to just pass the EPA, then fit something thats quieter, not get as much attention but still maybe over the limit a little bit???


Cos i think its only becuase atm ur car is really F-ing loud which draws unwanted attention to you, if it was just a little bit over they prob would let you slide a lot of the time....

p.s When we going for a spin next?

[Struggler]

FWIW, in my experience noise reduction is directly related to volume, ie. the bigger the volume of the muffler the quieter it will be (check out the rear mufflers on most modern cars). If you have the room I highly recommend straight thru truck mufflers (easy to say when you own a tonner - heaps of room !)

If the muffler you are currently using is the Lukey (or redback copy) I reckon they are crap. I removed these (2 of 2.5") and replaced them with the Walker Super Turbo (also 2 of but in 2.25" ) and picked up a tenth, and heaps quieter. I used to swear by the Lukey, but paint used to always burn away from the middle of the muffler (where the expansion chamber is). That got me thinking that it was obviously a large restriction (gases getting confused). Also removing the Lukey equipped exhaust and running open pipes gained me .25 sec ET and 2 MPH (too big a difference). I have also used a single 2.5" Super Turbo on a 12 sec 308, removing it had no effect on ET or MPH, despite losing about 40Kg of weight.

The Hookers sound and flow great, but are not the quietest. Perhaps they would work OK in association with what you have. A mate has a 12 sec SBC and runs twin 3" to the diff with the Hookers. Sounds great and goes as well as open pipes. For street use he bolts on a pair of 2" press bent tail pipes with resonators!! This knocks heaps of noise out of it and still retains drivability. Won't rev past 5000rpm though !!

Good luck with whatever you decide on.

[LXCHEV]

Matty - what you said are my thoughts EXACTLY. You couldn't have summed it up any better. I want to get it down under the 96dB to pass the noise test, and from then onwards run a system that is quieter than what I have at the moment, but if it's still over the limit a tiny bit, at least it won't be drawing the attention like it does at the moment (A happy compromise). As for going for a spin - yep we must go out sometime soon 4 sure! I still need to take makka for a ride too!

Struggler and Lostit, thanks for the thoughts guys.

Struggler - interesting what you mentioned about the heat/paint burn off in the middle of the mufflers around the expansion chamber - I noticed mine are doing this when it was up on a hoist the other week (only slightly, but definitely noticeable). These are SuperCat mufflers. I am definitely getting ridding of them now.

Lostit - with my previous exhaust system, I too also found it felt better and smoother & revved a lot cleaner with the system fitted (as opposed to open pipes), and open pipes made no difference to quarter mile time at all. I haven't had a chance to run my new setup open pipes though just yet.

Ok, it looks like I'm now chasing the biggest possible mufflers I can fit.

Cheers again all, this is great stuff to read...

[LXCHEV]

Also one more question Struggler - the Walker Super Turbo's you mentioned - what design are these mufflers? (triple flow or still straight-through??).

What's the go with Walker? Are Walker and Lukey one and the same or not? On Lukey's website I can only find a Turbo muffler, no sign of a Super Turbo....

[Struggler]

Also one more question Struggler - the Walker Super Turbo's you mentioned - what design are these mufflers? (triple flow or still straight-through??).


What's the go with Walker? Are Walker and Lukey one and the same or not? On Lukey's website I can only find a Turbo muffler, no sign of a Super Turbo....

Triple pass, I know they look restrictive but they have always worked for me.

No, I think Lukey and Walker are two seperate entities. I know Walker is a worldwide exhaust manufacturer, believe Lukey is Australian only.

OK, just did a search..... the old Walker brand is now manufactured by Dynomax. Plenty of info on their site.

[LXCHEV]

Awesome, thanks Struggler. Found a pic of the Dynomax Super Turbo, they look good.

Anyone know of any places in Australia that distribute Dynomax mufflers???

[makka]

how about redbacks? I have heard good things about them too, and brett, maybe you could come in tonite and take matty and I for a spin

Edited by makka, 22 June 2006 - 02:29 PM.

[LXCHEV]

If I can't get hold of a pair of Dynomax mufflers, I will most likely try some Redback Triple-Pass units. But the reason I would like to try the Dynomax ones is because they seem to have a good reputation in motorsport use, yet still being quiet.