28 replies to this topic

[Orange SS]

I am just wondering what mufflers everyone is using or what might make my new engine sounds the best.

 

I am finally fitting the 355 stroker I have had built. It's an early headed 355 with roller cam, twin 2.5 inch system with new pacemaker extractors, manualised trimatic and 9 inch. Cam spec 242 & 250 @.50 and .595 with the early heads flowing at 240cfm @.700.

 

I don't need it to be overly loud and it'd probably an overkill with the 2.5 inch system. I am trying to avoid any droning noise but still want it to sound and perform nicely.

[Redslur]

Whatever you choose be hard to get something like that quiet. I am running XForce but they are too loud.  I personally like Redback.

[Holdenbn74]

I'm running 2.5" Hooker aero chambers with hotdogs in front of them, love the sound but are loud..

[Ando]

Matt, I've got similar engine specs to yours with the 13/4 tri-y Pacemakers. Also have 21/2 pipes to the 3"x14" mufflers & 3" tailpipes. My exhaust has been a bit of a piece meal job over time but happy with the resalt. I got mine done recently by Bill Collier from Bills Tweed City Mufflers 5523 2455. Can't say what brand the mufflers are but Bill could tell you. Cheers..

[mick_in_oz]

Pacemaker Tri-Y 1-5/8" with merged and lengthened primaries and secondaries, twin 2-1/2" with balance pipe, Dynomax Race Magnum (old, think they are now the Ultraflow welded) hand made mandrel 2-1/2" tail pipes. Sounds great, moderately loud, no droning, very unique sound mostly coming from the modified extractors methinks, it was amazing how different it sounded after the extractors were modified. For a straight through muffler I'd call them quiet.

 

Previous engine was 326 with solid roller, early iron heads, similar to a crane 288 but with .700" lift, 483 moroso HP, spinning to 8000, new engine 363 with lots more cam, solid roller, more comp, YT Dash 3 heads, still sounds similar.

 

Perhaps the most obvious sound from the exhaust is the compression crackle it has as soon as it starts to get on the cam a little.

Edited by mick_in_oz, 15 November 2016 - 09:02 PM.

[dattoman]

I plant to rego my car with something nice and quiet

Once I have plates

These are going on

 

http://zetti.com/ind...dex/STR7950-409

[Orange SS]

thanks for the info. I have redback mufflers on my old 2.25 inch system but no balance pipe and it sounded pretty good so I may run with them again with the 2.5 system with a balance pipe.

I might give the exhaust shop at tweed a call as they're only 20min down the road.

 

thanks again for the info guys!

[YELLAcakeu308]

Hi Mick in Oz,

Is it possible to post up a pic of your modified pacemakers?

[LXCHEV]

Hi mate.

Whilst mine is a SBC and not Holden, it's another similar combo to yours. Stroker, roller cam (236/242), Tri-Y's with twin 2.5" system.

I think my mufflers are Supercats (interference chamber style, NOT straight through). Certainly nothing luxurious. I'm running twin hotdogs too (before the mufflers). With tailpipes fitted, it's fairly sedate. With dump pipes at the diff, it sounds much grumpier! Still runs 11's so I don't believe there is any restriction/performance loss.

Oh yeah - I have an X-pipe too. That alone improved the note on mine a lot. At a minimum run a traditional balance pipe. I get quite a few comments on mine from people saying it sounds sweet.

Have also used Redbacks in the past and reckon they're good too. Have mates running Lukey's - also a nice note, but can be noisy.

I personally think x-pipes, balance pipes, and hot dogs can be used to really tame down a noisy system.

Food for thought, hope it helps.

[derrin71]

I have stainless dynomax straight through's on mine, you can literally look straight through the chamber, stainless steel packed with a perforated core. Remember compression ratio and cam specs have a HUGE effect on sound. Avoid chamber type mufflers. They can give the old thong slapper sound. (I used to work in an exhaust shop)

[Orange SS]

I've got 10.4 to 1 compression ratio.
I don't want the slapper sound so thank you for that info!

[Pop's-SS]

G'day Matt

 

I've only got a 2 inch twin system feeding from extractors to Berkeley BS808 mufflers before the diff

 

Sound is deep and growly ? not tinny

 

RegardSS .... Barry

Edited by Pop's-SS, 18 November 2016 - 06:41 PM.

[derrin71]

To pick a chamber muffler you need to look into one end you won't be able to see  through it. It will look like a dead end with plates welded into it to force the exhaust gasses around inside the chamber. A turbo type one (nothing to do with being suitable for turbo engines) will have curved deflector plates inside which smoothly route the exhaust through the muffler. Dynomax Super Turbo used to be ones like this and are good as well.

[grumpy xu1]

That's what the hooker areo chambers are like, they don't drone. That would be the way I'd go for sure if you can fit them, they're a lot thicker steel, sound tuff, i run them on my cluby. I have x force on the ss & they're just rubbish. They will be replaced with hookers in the future, Buy the hookers for sure. Ask the previous member if he could send you a quick clip of his car with the aerochambers maybe ? Gary.

[Racehatch]

+1 for balance or x pipe to stop thong slapper sound!


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[grumpy xu1]

Yeah i forgot to mention that before x pipe you can buy these fittings at the exhaust shop

[Orange SS]

great info there! I would like to have a nice deep grumble without the slapping and still hopefully within legal noise limits to avoid too much unwanted attention from the local police.

 

There's not too much difference between a 'H 'or 'X' balance pipe is there? I am putting in a 'H' balance pipe at this stage. Is the size of the 'H' pipe critical? I was going to use a 1 or 1.5 inch pipe provided there's no reason to use the same as the rest of the exhaust.

 

I bought brand new pacemakers(their 'competition' header with slightly larger primary & secondary pipes), 2.5 inch mandrel bent tailpipes and all the pipe & fittings to make the exhaust off an exhaust shop advertising on gumtree for roughly half the price of local shops.

 

I am not going to do this as 3 inch pipe restricts ground clearance too much but the guy who built my engine actually recommended dual 3 inch pipe from the extractors to the diff then 2.5 inch over the diff to the rear.  his reasoning was that exhaust gas cools enough by the time its got to the diff that a 2.5 inch pipe is all that is required. I cannot see my engine getting much benefit from something like this as I am still running early heads and they'd probably be holding the engine back more than the exhaust system.

 

My engine is completely satin/matte black however I was disappointed with what the ceramic coaters told me after I had the extractors coated. I thought they coated the inside of them too which would prevent them rusting and also possibly assist with air flow slightly but they only spray the ceramic coating in the ends a little apparently.

[dattoman]

Sounds similar to mine

The outlet on the extractors is 2.5 " ?

 

I'm going to use this merge

 

http://www.pacemaker..._category_id=43

 

[Holdenbn74]

Here's my twin2.5" hookers, dogs and cats☺️
Running behind an LS though.. love the note.

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[grumpy xu1]

Mine is similar to above, i have hooker aerochambers & MagnaFlow cats 200 cell, mandrel bends & 4 bolt flanges & an x pipe. Very deep sounding muffler, that's 1 of their selling points. Holley ect sell x pipes mate, you could try tuff car parts & see if Justin has them, i got the mufflers & cats of him 2.5" all the way, i think that's all I'd use on a 355 ci, there's plenty of hype about running 3" on an ls1 n/a & they actually make less power, but more noise ! 1 of my friends used to build extractors ect in his fab business & always runs with 3" only over 400ci that's n/a though. So 2.5" would be the go, Gary.

[Racehatch]

What diff ratio are you running?


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[grumpy xu1]

I'm assuming that you're asking orange ss that ratio question mate ?

[Orange SS]

The rest of the driveline is a 3.5 true track 9 inch & manualised trimatic with 3800 stall

[Orange SS]

Hey guys, have any of you had dramas fitting the 2.5 inch system over the diff without any of it hitting the floor or diff??

[grumpy xu1]

When I've had lh/lx I'm sure that you can fit in 2.5" mandrel bends, but no bigger by memory ! Gary