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Finished my cheap exhaust!!! WOOHOO!

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Old 11-02-07, 08:07 PM
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rotors excite me

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Finished my cheap exhaust!!! WOOHOO!

'87 TII. Yesterday I finally installed my Thrush Turbo muffler between the 2.5" pipe, 2.5" dp, stockish y-pipe and cans. Extremely quiet now, and was deafeningly loud without. Phew! It's not perfect, and the welds aren't pretty, but I'm quite pleased. I borrowed a friend's MIG welder and learned how to MIG weld yesterday. I've done arc and acetylene before.

Music. To. My. Ears.

Costs:
Thrush Turbo muffler (came with a decal, LOL!): $25
Gaskets: $8
Flanges: $10
Pipe: $5
Way too much flux core welding wire: $20
Getting my wife to like riding in the RX-7: priceless!

Pic (intake is at the right side):


Audio:
http://www.zshare.net/audio/4631052bac8697/
http://www.zshare.net/audio/4631069a4bb3c1/
http://www.zshare.net/audio/4631085b868df3/

In the first file I mention how the new sound is sublime, and something about how it's almost too quiet. I'm thrilled.

I'm no longer boost creeping, at all until hard on 4th and even then I don't think it's past 6 psi. I need to test that more before I ditch the vac gauge I've had hanging in my passenger window. However, I hit 5 psi by around 3000 RPM in 2nd and higher, which frickin' rocks.

PS: To all you who said this wouldn't work: HA!!
Old 11-02-07, 08:34 PM
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Blazin' 87 N/A

 
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good shyt man!!! sounds really good!!! and who the hell cares if the welds are purrty!!!???!!! only show queens thats who!!!!!!!
Old 11-03-07, 10:22 AM
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I "lost" my emissions....

 
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wonder how this would flow compared to my strait pipes, or a high flo cat.
ive been debating weather to go for quiet or quiet and emmissions complient... lol
believe it or not my n/a is louder than your t2 was
Old 11-03-07, 10:39 AM
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rotors excite me

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Originally Posted by DREYKO
wonder how this would flow compared to my strait pipes, or a high flo cat.
ive been debating weather to go for quiet or quiet and emmissions complient... lol
believe it or not my n/a is louder than your t2 was
that's not surprising, the turbo itself, even with just a downpipe, acts as a silencer. a straight pipe NA is another step toward insanity and deafness, haha.

I'd be very surprised if a high flow cat could outflow my setup, but I suppose if it was big enough and the pores were huge then it might be able to.

as for emissions compliant... I'd say do only what's necessary for your state. in Iowa we don't have ANY emissions testing, the farthest they go is checking for cats, and it's rare that cops do. they're much more concerned with the noise regulations, at least around here.

now I need to bend the muffler hangers so they stop touching my bumper. they came like that and they had melted the bumper some; rather annoying, that. I just think I'll have to pull them off the car to do it...
Old 11-03-07, 10:40 AM
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Originally Posted by rxmclaren7
good shyt man!!! sounds really good!!! and who the hell cares if the welds are purrty!!!???!!! only show queens thats who!!!!!!!
thanks
Old 11-03-07, 02:07 PM
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Rotary $ > AMG $

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I told you it WOULD work!

Originally Posted by jackhild59
Try a 2.5"x14" turbo muffler installed between the dp and y-pipe. They are relatively cheap, freeflowing and tend to have a low tone. I don't think the sound will come out raspy.

http://store.summitracing.com/partde...5&autoview=sku
Way to go, nice sound.
Old 11-03-07, 04:25 PM
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well wouldn't the lack of a boost spike indicate that the exhaust isn't flowing as freely as before?

what exhaust were you running before? current and future mods?

Good job on the setup tho, i bet your ears and your neighbors thank you.
Old 11-03-07, 11:30 PM
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rotors excite me

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Originally Posted by phoenix7
well wouldn't the lack of a boost spike indicate that the exhaust isn't flowing as freely as before?

what exhaust were you running before? current and future mods?

Good job on the setup tho, i bet your ears and your neighbors thank you.
Of course it indicates that. Though somewhat indirectly, I did say that I had previously just been running a downpipe. So that answers your first two questions.

Current mods: pulled emissions, ported wg, dp, the Thrush 2.5" muffler, yanked hatch padding *shrug*.

Future: I plan on rewiring my fuel pump and rebuilding hopefully within a year, and hopefully before the motor gives out. Main things I need to do are maintenance, but I have an Rtek 1.7 and 720cc injectors waiting for when I get a higher flowing fuel pump, and then I'll find a way to increase my boost to maybe 8 psi. I don't want to be too demanding of this motor, yet it should be able to manage 8 psi decent enough, it was hitting 8 psi hard with just the downpipe, and it's still alive...
Old 11-04-07, 01:00 AM
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A Thrush turbo muffler? Wow. Gross. Who names this crap?

http://www.webmd.com/oral-health/tc/...topic-overview
Old 11-04-07, 02:03 AM
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I'm a boost creep...

 
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Originally Posted by phoenix7
well wouldn't the lack of a boost spike indicate that the exhaust isn't flowing as freely as before?
No surprise there. "Turbo" mufflers are very restrictive.
Old 11-04-07, 05:11 PM
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lol
http://en.wikipedia.org/wiki/Thrush_%28bird%29
http://en.wikipedia.org/wiki/Candidiasis
The Thrush mascot looks to like a knockoff of Woody Woodpecker, so I at least figure they weren't aiming at a disease for their name...

anyway I know the muffler reduces the pipe diameter some inside the unit, but it was much less reduction than that of another cheap muffler I looked at. even so, I'd have a hard time believing it's more restrictive than two cats.

and like I said, anything added to the previous exhaust would be more restrictive because it had just been a downpipe on there.

now I'm curious if I'm shooting flames every time I hear the exhaust pop... is there a way to check this just by revving in neutral?
Old 11-04-07, 05:55 PM
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if you're running rich enough then you'll see the flames when in neutral and revving to redline.
Old 11-04-07, 07:13 PM
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Rotary $ > AMG $

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Originally Posted by phoenix7
well wouldn't the lack of a boost spike indicate that the exhaust isn't flowing as freely as before?

what exhaust were you running before? current and future mods?

Good job on the setup tho, i bet your ears and your neighbors thank you.
Of *course* it's more restrictive. He was running only a downpipe before. Everything is more restrictive than a wide open downpipe.

He also had blood pouring out of his ears.

The Turbo type is much less restrictive than anything except a strait through muffler. He unfortunately also chose the Thrush, which has a reputation for being more restrictive than most turbo mufflers.
Old 11-04-07, 08:39 PM
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Originally Posted by jackhild59
He also had blood pouring out of his ears.
Nah, that doesn't happen until your run a ported NA (with no diffusers) open header. THAT is loud.
Old 11-04-07, 09:52 PM
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I'm a boost creep...

 
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Originally Posted by SpeedOfLife
l...I know the muffler reduces the pipe diameter some inside the unit, but it was much less reduction than that of another cheap muffler I looked at. even so, I'd have a hard time believing it's more restrictive than two cats.
I don't know about any reduction in diameter, but inside those mufflers the gases are turned back around 180deg twice while passing through the chambers, which is great for noise suppression but not great for flow.
Old 11-04-07, 10:49 PM
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Originally Posted by NZConvertible
I don't know about any reduction in diameter, but inside those mufflers the gases are turned back around 180deg twice while passing through the chambers, which is great for noise suppression but not great for flow.
true. but I am certain about pipe diameter reduction, I looked inside the mufflers I was looking at before buying one.
Old 11-04-07, 11:33 PM
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the exhaust sounds great but I have to say that you need to get some shielding gas for your mig so you can weld GMAW and get cleaner welds better penetration and very little spatter. its cheaper in the long run to cause my 80 C.U. Ft. cylinder cost about $200 and once you own the cylinder it just costs $20 to fill it with 25% co2 and 75% argon. anyways I did the exhaust on my scion tc with a Spintech muffler and when I get my 7 running I will probably use another spintech can cause they have a really unique sound and doesn't sound like a cheap resonator.
Old 11-05-07, 12:15 AM
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get some sound clips
Old 11-05-07, 11:48 AM
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it's not my welder, and since I don't OWN the garage and I have limited space, if I get a welder I would like to have it as compact as possible. the little MIG welder I borrowed is a great size. I also figure I probably didn't tune it as well as I could have, but I will probably do some more MIG welding before too long so I'll get some more practice.

phoenix, are you talking to me or endofcomment?
Old 11-05-07, 04:57 PM
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end ofcomment because you already posted your sound clips. I doubt you miss your old open DP setup but how do you like it so far?
Old 11-05-07, 09:41 PM
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it's very comfortable and smooth. nowhere in the RPM range does it rattle (I was careful to keep the pieces clear of the body, 3/4" minimum. that paid off), it seems to flow well despite the muffler's design, and it never gets loud *shrug*. sometimes when I'm pushing it hard I kind of wish it would roar a little more when working hard, but I suspect I might get tired of that effect and it would also be easier to attract unwanted attention. I need to do some more measured tests to see if my power has suffered much, but it doesn't seem like it so far.
Old 11-11-07, 11:25 PM
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nah I understand what you are saying about the space issue I live in a 2 bedroom apt with a flat mate and I have two welders a 110volt lincoln mig and a miller 110-230volt tig the tig is tiny but the mig I have on a cart with an 80 c.u. ft. gas cylinder I store it in my room and weld on my patio when I need to. I will work on getting a sound clip for you tomorrow it sound pretty much the same as this http://media.putfile.com/SpinTech-Pro-Street-clip

Speed just a hint on the welding if you get a scrap piece of metal that is close to the same thickness and then run a couple beads to "tune" the welder from the looks of it you need to crank your amperage up and the more you crank the amps up the more the wire speed needs to go up cause if the amps are high and the wire speed is low it acts like a really fast fuse and the arc will melt the wire faster than your feeding it, btw is that using gas or just inner shield wire? anyways another tip is you might want to clean all the galvanization off the metal your welding the zinc burns off and acts as an impurity and you will get shitty welds no mater what, I use muriatic acid to take zinc off metal it works great, you can also get something called metal fume fever from welding galvanized metals from inhaling the burnt zinc.
Old 11-12-07, 08:53 PM
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it's a no-gas welder, and I think I forgot to clear the galvy off before welding. I do understand the part about voltage/heat and wire speed, and I did tune it enough so that I wasn't burning through easily *shrug*
Old 12-14-07, 11:52 PM
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A month after installing this, I love it. I did find a tiny leak through one of my welds, though, so I need to patch that and add a hanger or two as well, then possibly paint it so it will be a little more rust resistant.
Old 12-15-07, 09:23 AM
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"Way too much flux core welding wire: $20"


LAWL thats awesome


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