Dual Exhaust

[Robert Stamps]

When you do dual exhaust with one muffler ( I think you guys call it "one in and two out"), does it effect the performance of the vehicle in either a positive or negative way? I'd like to do duals ( and a low volulme magnaflow) on my 09 for a late Christmas present to myself. Any suggestions would be greatly appreciated. Thanks

 

[Jim Upton]

looking to do the same here!

 

[Carey Frennier]

Hopefully Bob C will chime in. I lost torque with my magnaflow catback. I'd assume it would be the same with a single in dual out muffler since the mayor restriction is the resonator and the muffler itself.

 

[Robert Caffyn]

Merry Christmas all!! Bob, I used all 2.5" parts for my setup. The two OBDII cats(hi-flow) the dual in/dual out muffler and exhaust tips were from Magnaflow. I'd have to go back to get the part #'s. You'll need a competent muffler shop. I had to take the manifolds off anyway, as several of the bolts were broken 1st: have him/her make up the cats to bolt directly to each exhaust manifold. Have them make up two pipes to go from there to the muffler( which will be mounted as far back as possible). Then make up two tailpipe sections to go around the spare tire(but over the center section of the rear). Add the tips of your choice or not. It would look ok either way. I'll show the pictures of my setup again. Good luck, Bob



This is from the front of the muffler looking towards the engine

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This the rear of the muffler

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And the finished off rear end.

[Broken External Image]:

 

[EddieS'04]

For true duals, on a N/A street motor. Do not over size your pipes. IMO, to mantain TQ/HP and gain some. On a V8. With one twin core muffler, 2in/2out. 2 1/8 to 2 1/4" tubing. For a V6, 2" to 2 1/8". With 2 mufflers. I might use the smaller of the two.



Common mistake is thinking. Larger pipe is better. I have seen people put 3" pipe on. Then wonder where the low end grunt went. 3" pipe is even too large for single exhaust on a street motor. Less than 400 cui.



Large tubing is ok on a drag car. Most are tuned for it. Plus they are launging at 4k to 5k rpms. Yes they need that TQ but, after 60feet you need all HP. The large tubing will support that.

 

[Robert Caffyn]

Eddie, one thing I forgot to mention is, when the mechanic got to the tailpipes, he shrunk the pipe to fit into a 2.25" exhaust tip. This kept my back pressures up. Plus, the internal cross-over inside the muffler boosted the torque and evened out the exhaust flow. So I didn't lose, I actually made some gains in the HP/torque (at least it feels that way, only a dyno will tell for sure). Bob

PS: I told you I really think these thing through. Except for the header debacle!

 

[EddieS'04]

PS: I told you I really think these thing through.

Bob C, thats good:supercool:. You did a good job.

I see so many youngster around me, that dont. They rebuild the system with what they think is cool looking. Some shops wont tell them the ends and outs of performance exhaust. So thay give them what they ask for.

Then they wonder why there car runs bad and sounds funky....:bwahaha:

Except for the header debacle!

Have you looked into the non eqaul length shortys..?

They tuck in closer to the motor.

 

[Ray Muratore]

Very nice Bob.. I'm posting so I can keep a tab on this thread for a latter project! Just need to figure out a nice clean way to mod the STA rear fascia.