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Truenotch

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I will be going down this route again soon on my 3.3 Commy.

I had a pair of 2" but was a bit too much bark so will do a single 2.5 soon. The current setup up sounds ok but the primaries are too small as I made a set of 202 headers fit my 12-port 3.3. The 202 headers sound much nicer IMO than the EFI as they take the front 3 into and 1 and rear 3 into 1 with a longish runner before collecting which gives it a nice rumble.

I would like to make a custom set with bigger pipe all the way through. I find when the exhaust is slightly smaller it tends to give it the desired rumble in the car but can sound a bit squeezed out the rear. I hope this makes sense?

Does this sound any good or do I just go big and loud??

 

 

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what size primary's are on it now?  
so it has a twin 2" system on it?  and going to go to  a single 2.5"? 

you maybe heading on the wrong direction  going bigger primary's,  especially  if downsizing exhaust (twin 2"  is bigger area than single 2.5")

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21 hours ago, kpr said:

what size primary's are on it now?  
so it has a twin 2" system on it?  and going to go to  a single 2.5"? 

you maybe heading on the wrong direction  going bigger primary's,  especially  if downsizing exhaust (twin 2"  is bigger area than single 2.5")

No one had used twin system on these for many years so thought I would try it but to get it to sound like the old ones it needs to be a bit smaller, maybe 1 5/8"

I made a twin 2" system to try then dropped to single 2" to get my WOF which runs ok considering the primaries are so small but I know I can get better with bigger primaries.

Current Primaries are about 32mm but I need 38 to get close to the port size, and make the first 2 collectors  2" then into a 2.5" with no muffler but 1 fibreglass resonator or maybe 2 just to take the sharpness away.

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I'm keen to build a 3" system for my 2.0 turbo but for nats it won't be turbo just n/a with the turbo manifold (it needs a new exhaust but I might as well build the one it's gonna end up with rather than waste time on one that won't be permanent)What's the deal with short primaries into one and what should I do to stop it being stupid loud? I'm keen to have it exit in front of the rear wheel. Also I'd like to hard mount it (semi), does that mean I need a super long flexi joint or is hard mounting it just a stupid idea.. 

The other question is, is there anyone in nz that builds mufflers with the inlet and outlet at the same end rather than straight through? 

Soz for all the questions, I've been thinking about it for a while and not to sure which way to go

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Turbos seem to remove a lot of the harsh bark from the exhaust note but some engines make more noise than others. I think bigger N/A exhausts tend to be loud and echo without much exhaust note but glass packed resonators can help take 'bang' out but of course you need room for the 3" and the muffler/resonator so  you may be limited for clearance as if you have 3" under the sill how low is the car going to be or do you scallop the sill?

I really like the glass fibre noise limiters as you can have good unrestricted  flow and they help make a nicer note with rumble.

 

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need all the mufflers to make n/a quiet with big exhaust.   couple of reso's  and  big  non straight through at rear, swap it out for a straight through when going turbo.  i say this, as likely have  a hard time finding non restrictive muffler that shuts it up in 3" for a decent price.        short primary's obviously  aren't great on n/a, but will be fine otherwise 

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8 minutes ago, kpr said:

need all the mufflers to make n/a quiet with big exhaust.   couple of reso's  and  big  non straight through at rear, swap it out for a straight through when going turbo.  i say this, as likely have  a hard time finding non restrictive muffler that shuts it up in 3" for a decent price.        short primary's obviously  aren't great on n/a, but will be fine otherwise 

 

Mmm.. maybe I'll just have to go smaller, it won't be very long as I want to exit it out the side before the back wheel. You don't by chance know who makes/stocks same end in out mufflers in nz do you? Or is it just easier to make one.. 

 

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i usually make my own, so haven't looked into it much.  but try adrenalinr.   think they will custom make  if they don't have what you need.    otherwise if you have some room loop 2 together.

its really a bit of trial and error sometimes.  as holdenman says some engines are easier to shut up.      generally  you want at least 2 different syles/shapes/sizes of mufflers to shut up different tones.    

/beaten by @cletus

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21 hours ago, kpr said:

i usually make my own, so haven't looked into it much.  but try adrenalinr.   think they will custom make  if they don't have what you need.    otherwise if you have some room loop 2 together.

its really a bit of trial and error sometimes.  as holdenman says some engines are easier to shut up.      generally  you want at least 2 different syles/shapes/sizes of mufflers to shut up different tones.    

/beaten by @cletus

 

Be quite keen to make my own, need a bit of guidance as to what works do for / noise.. Bring titbit noise shouldn't be too much of an issue..  Have you had any experience with the vortex style baffles? 

 

Screenshot_20200121_223021.jpg.dd7701658aab5b6ebd8741b7c1c26d53.jpg

 

 

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Haven't tried anything like that.     mostly straight though absorption, or multipass chambered.       one im currently using is a combo of both  seems to do a pretty good job on a cam'd 4age .  its pretty big, which helps the cause. 

 

pics in link below.   isn't pretty because is made from parts of the previous one that fell apart and junk had hanging about

 

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On 20/01/2020 at 22:39, kpr said:

need all the mufflers to make n/a quiet with big exhaust.   couple of reso's  and  big  non straight through at rear, swap it out for a straight through when going turbo.  i say this, as likely have  a hard time finding non restrictive muffler that shuts it up in 3" for a decent price.        short primary's obviously  aren't great on n/a, but will be fine otherwise 

I don't agree entirely with this as a rule although unsure of the motor in question as many oldschool motors such the Holden sixes are a quiet engine unlike most multi-valve engines. I mention the Holden 6 as it was designed in the 50's, production began in the early 60's and unless it has been worked considerably it doesn't rev very high. Each resonator drops 4dB and more to the point softens the bang.

Part No: EXHRESO-3-18
M&H resonator 3.0" x 18" fibreglassed packed exhaust silencer 4db lower spiral louvre core mild steel black finish 18" body , 23.5" total length 4" diamete

 

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Yeah i mentioned  that earlier.  (Not the holden bit..)As well as  Trial and error , unless you know someone with same setup or can do the science.    Bit different in his situation, but generally on a na engine that your trying to make power on. will have a big exhaust , cams , so yeah mufflers if want to use it on the street.   And adding mufflers in later sucks

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It's a 2.0 mazda ma 8v,  I've had a 2 1/4"  system on one before with a 600 an 400mm coby.. Was fairly rowdy but not horrific. This engine will be revved to around 6500rpm maybe 7000 if I feel game enough. It'll have a turb on it in the end but I was thinking of letting the engine breathe a bit for nats.. I might just wait till I turbo it as I'm running out of time.. 

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22 hours ago, kpr said:

Haven't tried anything like that.     mostly straight though absorption, or multipass chambered.       one im currently using is a combo of both  seems to do a pretty good job on a cam'd 4age .  its pretty big, which helps the cause. 

 

pics in link below.   isn't pretty because is made from parts of the previous one that fell apart and junk had hanging about

 

 

https://spintechmufflers.com/blog/spin-tech-entropy-muffler-technology/

 

Screenshot_20200122_215536.jpg.4bfccc6e621fc6bdc92e879f82d31267.jpg

 

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