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antrx technical discussion => general technical discussion => Topic started by: noss on Oct 6, 2013, 11:13AM

Title: flowmaster dbx / laminar flow mufflers
Post by: noss on Oct 6, 2013, 11:13AM
just wondering if anyone knows of any tests done on these mufflers, or can find any cfm rates etc? i've been looking most of the morning and haven't found much at all. this is flowmaster's info video

[youtube]http://www.youtube.com/watch?v=Xuww8Yjyzsk[/youtube]

and this is a video showing an example on a wrx, where the only muffler appears to be the dbx at the rear

[youtube]http://www.youtube.com/watch?v=uzBN2ivVMkQ[/youtube]

that video alone makes me think that this is the answer for my mini which is currently obnoxiously loud, my idea is that i would slip one of these laminar flow mufflers in instead of just a plain old resonator, giving me a total of 3 mufflers, i'm just trying to find info on the cfm, cause to me, these mufflers look quite restrictive.

if anyone can point me in the direction of something they've seen, it'd be appreciated.
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: Pure_Sincerity on Oct 6, 2013, 02:19PM
Offset mufflers reduce a lot of noise and rasp compared to centre to centre mufflers.

My 34 cam with a centre to centre super cat muffler. Was loud as hell, then I swapped to an offset muffler EXACTLY the same as my previous, noise was almost halved and personally I think it's a cleaner crisper sound as it takes out unwanted rasp.
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: noss on Oct 6, 2013, 07:00PM
unfortunately, my car isn't as big as an r34 and i don't have much room to put mufflers. i need something that will fit into a small amount of space. and yeh, i realise that an offset muffler would cut down the noise a bit.

this is the underside of a mini

(http://www.carmodsaustralia.com.au/ecommerce/products/2341/alta-mini-r53-cat-back-exhaust-stealth-black-r53-ampext100bk-2341-15937-lrg.jpg)

probably a bad example because the exhaust splits into two, with a muffler located on each side of the battery box.

(http://polyfedelicio.us/imgs/images/iSsxF.jpg)

and this is basically the exhaust i already have

(http://polyfedelicio.us/imgs/images/jtmkC.jpg)


so the idea is to stick something in between the catalytic converter and the split to the two mufflers.



Title: Re: flowmaster dbx / laminar flow mufflers
Post by: BEEFY_1600 on Oct 6, 2013, 09:25PM
We have the magnaflow system on ours noss im sure you know how loud they are i put another resonator in before the rear twins and it made huge difference to what it was. Its still bloody loud but more bearable.
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: pedro666 on Oct 7, 2013, 12:44AM
I too have been spending abit of time checking out mufflers, the Flowmaster are chamber system similar to the Hooker aero chamber, Magnaflow xl 3 chamber(oval & round), AERO exhausts Turbine STX .I would get the 18" resinator/hotdog you where contemplating first and go from there.
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: SSS on Oct 7, 2013, 08:23AM
Sorry mate, I think you'll be up for a bit of experimentation with this one.

I can't really see those Flowmaster Laminar flow mufflers flowing an awful lot, actually, with the design they have, it looks as though the flow would be very turbulent through that muffler; that is possibly what they are rely on to reduce dB's.

Shoot them an email requesting flow figures, if they are cagey and won't give you anything, stay away from them.

Could you fit a centre / centre aerochamber in at all?
Title: Re: Re: flowmaster dbx / laminar flow mufflers
Post by: noss on Oct 7, 2013, 11:16AM
Yeh Pedro I have an 18" resonator ready to go in. I'm just not convinced that it will be quiet enough. I was considering a 2nd one so basically all the piping between the cat and the split would be resonator.

But for the cost of a 2nd resonator (about 100$) I was wondering what other options were out there.

Beefy what length resonator did you put in?

In other thoughts are

- cut open the mufflers and see if their sound deadening material is why good. If not re pack them. I really don't think they're baffled

- replace current mufflers with something else like an aero chamber of they fit

On also Adam. I contacted them and they referred me to their faq stating that "flow benches are useless and a marketing gimmick, when was the last time you raced a flow bench?"

http://m.flowmastermufflers.com/?page_id=43

Third answer down.

Sent from my GT-N7100 using Tapatalk 2
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: BEEFY_1600 on Oct 7, 2013, 11:48AM
I put one of these on it was just a cheap fix to make it bearable till we sell it.

http://www.ebay.com.au/itm/12-LONG-2-5-C-C-IN-OUT-5-ROUND-MILD-STEEL-UNIVERSAL-RESONATOR-SPORTS-MUFFLER-/170961535852
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: Pure_Sincerity on Oct 7, 2013, 12:41PM
http://m.ebay.com.au/itm/390375662500?nav=SEARCH&sbk=1

I went with one of those. The centre pipe is hollow and the spiral design helps exhaust scavenging and stops vibration inside the exhaust piping to reduce noise.

I noticed no difference in power output, but it cut down the noise about 1/4 and took a lot of drone out when sitting on 100kmph on the motorway. The old guy who I picked it up from used to make them for the stone brothers racing team years back.
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: SSS on Oct 7, 2013, 01:06PM
On also Adam. I contacted them and they referred me to their faq stating that "flow benches are useless and a marketing gimmick, when was the last time you raced a flow bench?"

http://m.flowmastermufflers.com/?page_id=43

Third answer down.

Ahahahahahaha.....that's marketing speak for "we don't know WTF we are doing, so we'll just trial and error EVERYTHING".

I'd be worried that a muffler like this would have too large a pressure differential across it due to those perforated cones; visually, the flow patterns would be a mess.

Sorry I can't add anything of use!

Actually, have you got any room to fit in a pair of twin loop mufflers to replace the current ones at the rear? (that is, if the noise really is that big of an issue?)
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: pedro666 on Oct 7, 2013, 07:48PM
Quote
I went with one of those. The centre pipe is hollow and the spiral design helps exhaust scavenging and stops vibration inside the exhaust piping to reduce noise.

I have looked at these also , they should improve the flow a tad.

noss, if not sure, maybe fit it as far forward as you can so if you need a second you can just drop it in.
maybe go a pair of yoshimura's coming out the side? ::)
http://youtu.be/-MYFz_s_rNg
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: noss on Oct 8, 2013, 10:08AM
i have read that the spiral things are steaming piles of dog turds.

also the mini in that video pedro is a turbo, mine is s/c. so mine is like an extremely loud n/a motor, where as the turbos are quietened a little by the turbo itself.


edit: just looking around, interesting these guys are saying that the flowmaster dbx is quite loud on their cars, but they're using the dbx as the only muffler.

http://forums.vwvortex.com/showthread.php?5714958-Flowmaster-dBX-Muffler&p=82680168

Title: Re: flowmaster dbx / laminar flow mufflers
Post by: noss on Oct 8, 2013, 10:20AM
[youtube]http://www.youtube.com/watch?v=tkViCLogfG0[/youtube]

this guy has 2 of these flowmaster dbx mufflers, plus 2 magnaflows at the rear. doesn't sound quiet to me at all. and it's on an R53, so its all i need to hear. i guess though this doesn't cover cruise/drone.

for what its worth, ultimately i'm trying to kill a bit of the cabin drone while cruisng and not losing too much power, therefore noise when i'm really hitting the throttle is acceptable. its just so loud currently its no good for a daily driver. maybe it's cause i'm old now, but it really is bad. it doesn't have to be totally silent while cruising, but i'd just like to reduce it a bit. also considering wrapping a real thick layer of exhaust wrap over it to help reduce some drone, i know honda s2k guys do that with good results.
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: SSS on Oct 8, 2013, 10:50AM
2.5 centre in / out varex in the middle?
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: deviate on Oct 8, 2013, 10:50PM
The Varex works wonders loud as fuck open and nice and quiet closed
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: noss on Oct 9, 2013, 11:07AM
don't know if i want to bother with a varex. i had a manual exhaust valve on the pintara back in the day and it just felt so restricted and when it was closed it chewed heaps of fuel.

may be the only option if i can't quieten the sucker down enough. i'll install some resonators to start with, i'm not convinced that the flowmaster is even an option anymore after a bit more research.

hooker maxflow sounds like a go-er, but it would probably be resonators + replace the existing mufflers with hooker maxflows.
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: pedro666 on Oct 9, 2013, 12:00PM
Have you checked out Borla , they have stax of systems for the mini.
I ended up ordering an Apexi ws2. ;)
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: noss on Oct 9, 2013, 01:39PM
i'm not going to replace my exhaust. to be honest, i'm very hesitant to replace the mufflers, only reason being that my exhaust cost me so damn much!
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: deviate on Oct 9, 2013, 02:04PM
Honestly with the varex closediI don't actually notice any power loss but I don't have Mandrel bends in my exhaust so there is some restrictions anyway
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: pedro666 on Oct 10, 2013, 12:15AM
I didn't mean replace, but just configs..Anyway exhaust shops always add resonators last , if they are needed . You should do a before and after sound byte..
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: noss on Oct 10, 2013, 11:44AM
to answer your other question pedro, the borla exhausts are quite loud as well.

i'll see about doing some before and after sound clips. anyone have a db meter that i can borrow?
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: pedro666 on Oct 10, 2013, 06:48PM
there's an app for that....
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: noss on Oct 11, 2013, 01:54PM
lol. would rather a proper db meter. don't know how legit a phone app would be.
Title: Re: flowmaster dbx / laminar flow mufflers
Post by: MattJohn on Oct 11, 2013, 09:24PM
Would be a good comparison test ahaha.

My cheapo volt meter read ~13.5V car running whilst my turbo timer showed ~14V