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Discussion Starter · #1 · (Edited)
So a few months ago I started a custom exhaust project. I knew I wanted a deeper / throatier exhaust. My Tanabe Medalion had been accused of sounding a bit too ricey at WOT by my wife and friends and it got worse when I had a catalytic converter installed. So the manliest exhaust I could think of would be a Borla . . . I've always liked their deep throaty growl.

Long story short - I ended up going with 2x Borla mufflers on this car!

I have an oval Borla universal in the middle where normally a 'resonator' would be installed in your b-pipe and I also have a Borla universal in the back where the normal muffler goes. You can see in the pictures below that the Borla universals are pretty thin leaving you with lots of clearance if you're lowered.

I went with a center / center offset for the middle muffler and I went with a center / offset design for the rear muffler (a center / center won't work back there).

I had some local exhaust shops hook it all up and I finally got a pipe bent today that isn't severely pinched where it goes around the suspension by the trunk (this is normally where expensive aftermarket exhausts have a mandrel bent pipe). Unfortunately I couldn't find any one in SC / NC with a mandrel bender that could do my 2.5" piping without pinching it so this is the best I could do.

Here are some pics and video for your entertainment.
Here's a shot showing the pipe that should be mandrel bent connecting the middle muffler to the rear muffler:


You can see the 4" round Maganflow metal core catalytic up in the y-pipe near the front of the car. I absolutely unconditionally recommend this . . . it doesn't restrict flow at all that I can tell and it dramatically reduces the stink. You can see straight through the cat so it's not a traditional generic Joe Boo muffler shop restrictive cat. NOTE: It DOES increase drone (at least it did on my setup).

Here's a shot of the rear muffler and the Borla tip I had put on it:
Yeah the muffler doesn't look like it's sitting completely horizontal down there and it may not be - but it's so thin that it doesn't hang down any lower than a stock muffler and it doesn't look bad from behind the car.

Here's some more shots from the back:

Yeah I need to clean the tip better. :)



Here's a video of how it sounds outside the car in neutral and inside the car when I'm going WOT.

You can hear the thin-walled Mazzuri headers rasping in the background when I lift off . . . the only unpleasant sound on an otherwise perfect setup . . . the "hate" in my love / hate relationship with these . . . 'interesting' hand made headers. :)

As for drone - I won't lie - there is some . . . at 60mph there is a fairly mild deep bass drone . . . but its far less annoying than any other exhaust I've had mated to these headers (RMM, Tanabe Medallion, single Borla) so I am officially done with my exhaust project on this car. The drone from the other exhausts was higher in pitch and really wore on me over time . . . I've had these 2x mufflers on the car since before Christmas and the drone doesn't bother me in the slightest (but I also am hard of hearing in the bass frequencies so that could be why! :)

Anyways - if you feel like going with this setup it's pretty straight forward and fairly in-expensive.

Here are the parts:
  1. High flow catalytic from Magnaflow: HottExhaust -2.5 " ID 300 cell density Metallic Substrate Universal Catalytic Converter Magnaflow 59956
  2. Borla Universal Center / Center muffler (part 40653): Borla Performance Industries - Universal Mufflers, Tubing & Hardware - Turbo Mufflers
  3. Borla Universal Center / Offset muffler (part 40659): Borla Performance Industries - Universal Mufflers, Tubing & Hardware - Turbo Mufflers
  4. Borla stainless steel exhaust tip (part 20155): Borla Performance Industries - Polished Tips - Single Oval Rolled Angle-Cut w/Clamp
  5. Parts and Labor at a muffler shop - I paid about $15 for 4 feet of aluminized steel tubing and the labor varies but I wouldn't expect to pay more than a couple hundred.

If you want flanges between the various pieces for easier replacement (instead of having a solid tube going from the header back to the rear with no flanges) you can find 2.5" flanges on eBay pretty cheaply with gaskets. For some reason none of the muffler shops here stocked 2.5" flanges for use in exhaust systems . . . really wierd.
 
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Discussion Starter · #4 ·
The video link works fine for me - just wait longer - it's 12MB and high fidelity - no crappy youtube here! :)

Updated the thread with more pics from the back. The tip sticks out a bit farther than I would have liked - but I didn't want to push my luck by asking the guy to shorten it and risk having it rub somewhere (the pipe was rubbing against the trunk intermittently until this morning when I got it fixed with a new pipe).
 

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looks good bro
 

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Discussion Starter · #7 ·
Good call on the resize - sorry bout that! The pics are 800x600 now.
Did anyone watch the video? What do you think of the sound?
 

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Discussion Starter · #8 ·
FYI - I plan on dyno'ing the bizatch when I get back from D.C. next the week after next. Honestly don't know what to expect . . . I'll post the sheets when I get them.

My mods are:
1. SAFC tuned to a good ratio
2. PLP foam filter + intake pipe
3. Cam gear at like -4.7 or so
4. Mazzuri header + y pipe
5. Magnaflow cat in y-pipe
6. Borla straight through exhausts (2x)

So there should be pretty much no restriction in this setup except for the cat and maybe the non-mandrel bent pipe near the back - but that doesn't seem to be pinched too badly . . .
 

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Not looking to give you a hard time, but I don't see the point of this overdone system.

You selected the Mazzuri for max hp gains, but then added a cat and two mufflers to quiet down the system and clean up the exhuast a bit. The cat and 2 muffs re-create the restriction you were trying to get rid of, plus you're still experiencing drone on the highway.

I think you'd have equivalent performance and no drone if you went with the stock IS header/manifold, y-pipe, and a Borla catback system. This particular combo produces a nice, deep tone and is not buzzy or raspy at all.
 

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I know it is difficult to find a mandrel shop in NC, I have looked myself to no avail.

As for your set up, it just doesn't sound right to me. Actually, kind of like a 4 cylinder with an ebay pipe and I still hear some hissing. I would say the reason is actually your headers and that small borla exhaust. You should really try to stay with something a little larger in width and length, like a big magnaflow muffler and maybe a long ass and less restricting thrush resonator to replace that mid muffler. I think that is why you are still getting some drone. If you are happy with it though, and you don't mind the sound for the horsepower gains equation, then its all good. Did you ever think of just throwing on an Apexi WS muffler or cat-back set up? They really do sound nice on an inline 6.
 

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I just went with the Borla catback and another Borla universal muffler and matched the tailpipes.

That looks sick. I personally would have went with two big ass exhausts like the Apexi GT Spec (which is the one I have) but that looks mad nice either way. +rep
 

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Since I already had the catback and really loved the sound, I just duplicated the other side. Thanks.
 

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Mayo, that is wicked hot. Great Job.
Have some rep.
 

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it sounds like you have a BOV

maybe its js me...
 

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Mayo, that is wicked hot. Great Job.
Have some rep.
Many thanks Jay. I just sold the Vizage side skirts and ordered a set of D.Speed Falcon sides through Bulletproof Automotive. Once I get the Carson Tuned front bumper installed, eveything should flow well. That's the plan anyways.... ;)

it sounds like you have a BOV

maybe its js me...
It must be you. :lol: What's a BOV? :confused:
 

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Discussion Starter · #18 ·
Not looking to give you a hard time, but I don't see the point of this overdone system.

You selected the Mazzuri for max hp gains, but then added a cat and two mufflers to quiet down the system and clean up the exhuast a bit. The cat and 2 muffs re-create the restriction you were trying to get rid of, plus you're still experiencing drone on the highway.

I think you'd have equivalent performance and no drone if you went with the stock IS header/manifold, y-pipe, and a Borla catback system. This particular combo produces a nice, deep tone and is not buzzy or raspy at all.
No offense taken - I really don't understand exhaust theory as well as I would like but this should be a pretty free flowing setup compared to a baffled muffler setup. Both mufflers are straight through with no baffles and the catalytic converter flows more CFM than the exhaust so that shouldn't be any sort of bottleneck or restriction on the system. The drone definitely increases when I install the catalytic and I think that's just becuase it goes from 2.5" in diameter to 4" in diameter which must amplify the resonance at 60-65mph. You can certainly get rid of the drone with a baffled muffler like the stock one or one of the magnaflows with baffles but that sort of defeats the point of a free flow setup.

As for the metal rasp - that's the Mazzuri header unfortunately. The runners are pretty thin and well they just make a lot of noise on a setup like this. I've heard that sound in tons of other Mazzuri header videos mated to all manner of exhausts.
 

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Discussion Starter · #19 ·
I just went with the Borla catback and another Borla universal muffler and matched the tailpipes.
Dude this is MUCH better than the last dual exhaust setup I saw from another member. Do you have any better pictures of where you went from 1 back into 2 pipes? It looks like you converge down to 1 at the b-pipe but then go back to 2? Did you ever contemplate running 2 pipes to the back all the way from where the y-pipe goes down to 1??
 

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Like you, I know nothing about exhaust theory and just went to a local shop and told them what I wanted to do. I actualy expected them to install a Y-pipe but all they did was hook up a new pipe and "fused' it into the existing b-pipe. It's really not a "true" dual-exhaust. That would require two separate pipes but I'm not sure if you can do that with an inline-6? I did this set-up purely for cosmetics.







 
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