True duals vs Cat back
True duals vs Cat back Okay.. i have MAC header's, off road pipe, and a 4" mufflex single hide away cat back, flowmaster muffler.. When i went to Bowling Green this Weekand, i seen alot of the cars were running true duels cut off before the cat back, It didnt appear to be that they were running muffler's.. I know this sounds stupid but, is there a performance gain going with this setup? I dont run cat's and i dont have any emmisions restriction's. Not that my car sound's bad, but these car's where loud as hell.. Nineball was sitting with me and he told me to take a crayon and draw a line.. Where the crayon stops melting cut there.. Do i really want to cut my off road pipe or should i replace it with something else? Sorry for the long post but i am sold on this setup.. Just want to do it right.. 
Re: Exhaust Question There are tradeoffs with the exhaust NOT being routed out the back of the car. Typically noise and smell. Most do the duals for sound and weight savings. Performance - I believe a well designed y-pipe will flow as well as duals. Having not dynoed them back to back, I'll let other's step in with an opinion.
Re: Exhaust Question performance is negatable.....the "factory style" will flow more than any of us will ever do...
The only reason to do true duel is sound. NO catback can compare with true duels.....sorry...not happening...
....
The answer to the drone/smell/etc....DON'T DUMP IN FRONT OF THE AXLE.....go out the back....
If you go with 2.5" pipe, you can run along the drive shaft and then go right under (yes...UNDER) the axle and out the rear.
Now your probubly thinking "can't do it on a lowered car...." ... no no no...
....I have LG motorsports Coilovers and to give you an idea of how low I am, you can't put more than one finger in between the top of the front tire and the fender....its LOW!!! My SLP subframes "would" drag before the exhaust and thats only when I go over REALLY tall speed bumps. When the car is lifted off the ground, the rearend's swaybar just rests (does not even move the pipe) on the exhaust pipe. Its a really cool setup.
Chris
The only reason to do true duel is sound. NO catback can compare with true duels.....sorry...not happening...
....The answer to the drone/smell/etc....DON'T DUMP IN FRONT OF THE AXLE.....go out the back....
If you go with 2.5" pipe, you can run along the drive shaft and then go right under (yes...UNDER) the axle and out the rear.
Now your probubly thinking "can't do it on a lowered car...." ... no no no...
....I have LG motorsports Coilovers and to give you an idea of how low I am, you can't put more than one finger in between the top of the front tire and the fender....its LOW!!! My SLP subframes "would" drag before the exhaust and thats only when I go over REALLY tall speed bumps. When the car is lifted off the ground, the rearend's swaybar just rests (does not even move the pipe) on the exhaust pipe. Its a really cool setup. Chris
Trending Topics
Re: Exhaust Question Thanks for fixing that for me John.. So what i am gathering is.. no performance gain and the car will be loud as ****..lol (not that that is a bad thing) Am i better off staying with the system i alredy have?
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
TECH Fanatic
Joined: Feb 2003
Posts: 1,586
Likes: 0
From: Columbus, OH
Re: Exhaust Question
performance is negatable.....the "factory style" will flow more than any of us will ever do...
The only reason to do true duel is sound. NO catback can compare with true duels.....sorry...not happening... ....
The answer to the drone/smell/etc....DON'T DUMP IN FRONT OF THE AXLE.....go out the back....
If you go with 2.5" pipe, you can run along the drive shaft and then go right under (yes...UNDER) the axle and out the rear.
Now your probubly thinking "can't do it on a lowered car...." ... no no no... ....I have LG motorsports Coilovers and to give you an idea of how low I am, you can't put more than one finger in between the top of the front tire and the fender....its LOW!!! My SLP subframes "would" drag before the exhaust and thats only when I go over REALLY tall speed bumps. When the car is lifted off the ground, the rearend's swaybar just rests (does not even move the pipe) on the exhaust pipe. Its a really cool setup.
Chris
The only reason to do true duel is sound. NO catback can compare with true duels.....sorry...not happening...
....The answer to the drone/smell/etc....DON'T DUMP IN FRONT OF THE AXLE.....go out the back....
If you go with 2.5" pipe, you can run along the drive shaft and then go right under (yes...UNDER) the axle and out the rear.
Now your probubly thinking "can't do it on a lowered car...." ... no no no...
....I have LG motorsports Coilovers and to give you an idea of how low I am, you can't put more than one finger in between the top of the front tire and the fender....its LOW!!! My SLP subframes "would" drag before the exhaust and thats only when I go over REALLY tall speed bumps. When the car is lifted off the ground, the rearend's swaybar just rests (does not even move the pipe) on the exhaust pipe. Its a really cool setup. Chris
Re: Exhaust Question Sorry guys, but Im not sure I follow. Do true duals or a catback flow better? Which one puts out better numbers? I thought that if I replaced my Loudmout with true duals and have 2 bullet style mufflers (not resonaters), then it would quiet down a little. I thought that true duals would flow better because I figured that a y-pipe has a slight restriction over an x-pipe because of the drastic bend. I want a light exhaust, flows the best, and sounds good without it being so poppy and having a lot of resonance. I like the way it sounds at idle and at WOT, but when driving it normal, its too damn loud. If I do go with true duals, then I definately want it past the axle whether it'd be over or under it. I would like to see pics underneath. Thanks
TECH Enthusiast
Joined: Mar 2002
Posts: 602
Likes: 0
From: ft worth tx
Re: True duals vs Cat back How would duals not flow better? It scavenges the gases easier and faster. Not to mention the weight savings you would have over a catback. About a good 40-50lb difference. Ask Lane at www.laneswheels.com he gained 24rwhp in the midrange over his mac offroad y and a cutout, the fastest ls1's in the nation run duals for a reason. And the drone all depends on what type of mufflers you go with. Duals sound a hell of a lot better than a y-pipe will ever sound.
Re: True duals vs Cat back They probubly flow better, but the question is does it really matter. A loudmouth will flow more than just about any engine will need.
The reason people say "they don't flow more" is because you don't want to do true duels for hp. The gains will not be worth the cost. The only reason to do them is if you want the sound. Then any "improvment" will be an added bonus.
Chris
The reason people say "they don't flow more" is because you don't want to do true duels for hp. The gains will not be worth the cost. The only reason to do them is if you want the sound. Then any "improvment" will be an added bonus.
Chris
Launching!
Joined: Nov 2001
Posts: 284
Likes: 0
Re: Exhaust Question
performance is negatable.....the "factory style" will flow more than any of us will ever do...
The only reason to do true duel is sound. NO catback can compare with true duels.....sorry...not happening... ....
*** Agreed. I got lots of good comments this week while running with the Porshe Club at Watkins Glen. ***
The answer to the drone/smell/etc....DON'T DUMP IN FRONT OF THE AXLE.....go out the back....
If you go with 2.5" pipe, you can run along the drive shaft and then go right under (yes...UNDER) the axle and out the rear.
*** I have Grots, an X-pipe, no cats, and 3" all the way back, under the axle. There are two Magna Flow, straight through, mufflers tucked up behind the bumper, attached with flanges. Next step is to make two tail pipes, no mufflers, to switch in at the track. All things being equal, there is only 1/4" less ground clearance with 3" pipe. ***
Now your probubly thinking "can't do it on a lowered car...." ... no no no... ....I have LG motorsports Coilovers and to give you an idea of how low I am, you can't put more than one finger in between the top of the front tire and the fender....its LOW!!! My SLP subframes "would" drag before the exhaust and thats only when I go over REALLY tall speed bumps. When the car is lifted off the ground, the rearend's swaybar just rests (does not even move the pipe) on the exhaust pipe. Its a really cool setup.
*** My car is lowered 3/4" and clearance is definitely a problem. However, the car gets more miles on the road course than on the street. Can't clear speedbumps, and you got to watch out for dips in the road where the rear springs will compress because the pipes will drop with the body. But, I wanted max clearance for the sway bar and panhard for hard cornering on track. Maybe didn't need all that room. ***
Chris
The only reason to do true duel is sound. NO catback can compare with true duels.....sorry...not happening...
....*** Agreed. I got lots of good comments this week while running with the Porshe Club at Watkins Glen. ***
The answer to the drone/smell/etc....DON'T DUMP IN FRONT OF THE AXLE.....go out the back....
If you go with 2.5" pipe, you can run along the drive shaft and then go right under (yes...UNDER) the axle and out the rear.
*** I have Grots, an X-pipe, no cats, and 3" all the way back, under the axle. There are two Magna Flow, straight through, mufflers tucked up behind the bumper, attached with flanges. Next step is to make two tail pipes, no mufflers, to switch in at the track. All things being equal, there is only 1/4" less ground clearance with 3" pipe. ***
Now your probubly thinking "can't do it on a lowered car...." ... no no no...
....I have LG motorsports Coilovers and to give you an idea of how low I am, you can't put more than one finger in between the top of the front tire and the fender....its LOW!!! My SLP subframes "would" drag before the exhaust and thats only when I go over REALLY tall speed bumps. When the car is lifted off the ground, the rearend's swaybar just rests (does not even move the pipe) on the exhaust pipe. Its a really cool setup. *** My car is lowered 3/4" and clearance is definitely a problem. However, the car gets more miles on the road course than on the street. Can't clear speedbumps, and you got to watch out for dips in the road where the rear springs will compress because the pipes will drop with the body. But, I wanted max clearance for the sway bar and panhard for hard cornering on track. Maybe didn't need all that room. ***
Chris
TECH Enthusiast
Joined: Mar 2002
Posts: 602
Likes: 0
From: ft worth tx
Re: True duals vs Cat back Read my post again. With duals you will pick up a lot of midrange lacking with offroad y. If you compare the price a good catback/ory you will basically equal the price of duals. Sound is just a plus, I for one didn't want duals, I was set on borla with ory because I liked the way it sounded better, but I was told performance would be a lot different. So I went ahead and tried them out, and must say the sound is incredible, no rasp or drone period.
TECH Apprentice
Joined: Feb 2003
Posts: 325
Likes: 0
From: Platte City, MO
Re: True duals vs Cat back Does anyone here have a true dual setup with flowmasters over the axle and out the back? I think that would sound just wicked! (As you can tell I'm in it for the sound).
TECH Addict
Joined: Dec 2001
Posts: 2,264
Likes: 0
From: Cypress, TX
Re: True duals vs Cat back
Does anyone here have a true dual setup with flowmasters over the axle and out the back? I think that would sound just wicked! (As you can tell I'm in it for the sound).
http://www.angelfire.com/on2/Vinnie/truedual.html
TECH Junkie
Joined: Dec 2001
Posts: 3,242
Likes: 0
From: Lakeland, FL
Re: True duals vs Cat back I almost went duals, the only thing that stopped me was I did not want to smell like gas all the time. I compromised and put an electric cutout QTEC in the IPipe so i can open it up whenever I want, if you really wanted you could but dual cutouts on close to the headers and have it run like open headers if you wanted, Compared to a catback the duals would have to flow better and the weight savings would be a plus as well. You can probably get the flow out of a cutout but the weight is another story. You may have to ask yourself would duals be too loud in the long run and do you mind the smell of gas?
