Braineack

iTrader: (62)

look at the preforations, it definitely angles out. Also you can see the "wall" is smoothly formed, where it forms a slight V.

flowmaster 40 :




chambered mufflers don't use perforations and sound-deadening material. They use noise-canceling tech.


It's like trying to gag your mr. slave by putting him in a large room with partions, intead of just using a sock.

18psi

iTrader: (76)

the FM40 is garbage. so lets move along:

I'm not so sure it would be a mere 3hp lost from the split being the way it is - the exhaust gas is traveling directly into a wall, then being pushed to the side, going through the 2 passages, then hitting another wall, then being pushed against one another, and only then out the end. Does everyone really think that's "only" going to affect it 3hp worth?
Or am I just overthinking this in terms of flow and underthinking in terms of overall backpressure?

Mobius

iTrader: (2)

Partions? Brainie you been reading too many of Fae's broken posts

TurboTim

iTrader: (9)

Hmm ok. The first wall is not flat but pressed into a sorta V, like they do to their Y and X pipe exhausts. You can sorta see the opposite wall where the perforations are looks to be not flat too. The only icky area is where the straight preferatored tube mates to the pressed Y.

flounder

Oh they'll be vids... Quailty may vary.

I can't wait to show up with this huge muff at the shop tomorrow, my friends gonna slap me.

Hopefully I'll be driving home with this installed by tomorrow at 6pm.

Braineack

iTrader: (62)

yeah, and you forgort about thermal/fluid dynamics, pressure differentials, and all that jazz.

18psi

iTrader: (76)

flounder

I like to think of it as 2.5"+2.5"=5" of glory flow.

TurboTim

iTrader: (9)

Actually it's 3.536" of glory flow, but we get it.

EDIT: actually-actually it's probably something different taking into account whatever flows going to stick to the walls. I don't want to look up those equations.

flounder

It was a joke Tim.

flounder

It's really quiet.
How do I add a sound clip?

krissetsfire

iTrader: (1)

where's the dyno? w/ & w/out. it's been a whole day. we're all tired of waiting! I have the straight one not the bi one and it's pretty quiet. the bi one must be super quiet.

flounder

Much like mr. Sawzall, I don't have a dyno sheet.

It is whisper quiet from idle to redline, all I hear is the turbo spool up and the bov. It's spooky. The turbo spools up much faster, and hits 15psi about 500rpm sooner too. Seat of the pants dyno feels like at least a 25hp gain and it still needs to be retuned.

Braineack

iTrader: (62)

quite is awesome. upload video to youtube.

flounder

Sorry for the long delay with the vids but I've been working my *** off all week (65hrs by tomorrow).

I actually had some other questions about recording sound in the miata.

I was watching brains muffler vid and was wondering where you had the mic at? I'll basically be making my vid with an android, so I'm sure it will suck ***** but I'm gonna try my best.

BTW this exhaust really woke up the car. I read a lot about how much a free flowing exhaust would help on a turbo car but jesus christ! I've been working on the tune and this thing pulls like a freight train from 3.5k to redline. I swear I hear the tires chirp on the 3-4 upshift. I really need to get some dyno time scheduled and source a 3.9 diff at least.

I'm off on Sunday, so I should get the vid up sometime soon.

Braineack

iTrader: (62)

i use a dslr and it's mounted on my roll bar.

just make sure to turn down the volume or your stereo or we not be be able to hear it:

viperormiata

iTrader: (24)

Scott, you are the coolest mother ****** on earth.

How do you get all that thump? It sounds great.

Braineack

iTrader: (62)

subwoofer.

18psi

iTrader: (76)

this. All of this

viperormiata

iTrader: (24)

Thanks for the details. Since you gave no information I am going to assume it's mounted in your ***.