Building my own true duals
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Building my own true duals
Well I got around to finally making my own true dual exhaust w/x-pipe. I'm using 2 sets of 2.5" pipes following the stock location. Here are a couple of pics of the finished center section with x-pipe. I'm using SLP headers and cut off the y-pipe and started from there. I'm currently working on getting the tubes over the axles. Now the fun begins.




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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
Here is the finished product with LOTS of pics. The black paint on the welds is so they wont rust. I couldn't get the heat setting right at the beginning of the project which explain the "bubblegum" look of the welds at the header y-pipe but as I went along I got better at it. There is a video of the exhaust in my cardomain.








Last edited by pwdbychevy; Apr 14, 2010 at 07:45 PM.
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
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Last edited by pwdbychevy; Apr 14, 2010 at 07:46 PM.
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Re: Building my own true duals
That looks pretty good to me man. I think your WB O2 sensor is WAY too far away from the headers but thats your call. If it's heated it will still work there.
Also, do you have any pix of the car overall? I'm curious to see if you can see the muffler cases hanging down and if the tail pipes are centered. That is the reason I put my mufflers before the axle so they couldn't be seen from the side behind the rear wheels.
Also, do you have any pix of the car overall? I'm curious to see if you can see the muffler cases hanging down and if the tail pipes are centered. That is the reason I put my mufflers before the axle so they couldn't be seen from the side behind the rear wheels.
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Joined: Aug 2001
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
That looks pretty good to me man. I think your WB O2 sensor is WAY too far away from the headers but thats your call. If it's heated it will still work there.
Also, do you have any pix of the car overall? I'm curious to see if you can see the muffler cases hanging down and if the tail pipes are centered. That is the reason I put my mufflers before the axle so they couldn't be seen from the side behind the rear wheels.
Also, do you have any pix of the car overall? I'm curious to see if you can see the muffler cases hanging down and if the tail pipes are centered. That is the reason I put my mufflers before the axle so they couldn't be seen from the side behind the rear wheels.
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Thread Starter
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
Ok here's a couple of shots of the exhaust from the side and from the rear.


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From: sturgeon bay wisconsin
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Re: Building my own true duals
love that spoiler, any way cool exhaust , i like seein stuff thats home made and turns out good
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From: Bertram (outside Austin), TX
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Re: Building my own true duals
Congrats......
Your car is now heavier because of the exhaust (2 pipes instead of just 1). The sound might sound better to your ears, but as far as flow & efficiency goes? It is no better now.
Your car is now heavier because of the exhaust (2 pipes instead of just 1). The sound might sound better to your ears, but as far as flow & efficiency goes? It is no better now.
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From: Orlando
Car: 1991 Camaro Z28
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Re: Building my own true duals
Nice work man. I just did my brothers almost exactly like that so I know the amount of work that goes into it. I like how those mufflers tuck up. One question though. When you installed the pipes under the driveshaft, did you have the rear axle hanging down all the way? If not, on a big bump if the back of the car goes up high, the exhaust may hit the driveshaft.
Heavier by what, a pound or two? He could go pee before he drives if he needs a 1 pound weight savings. And I think most people would agree that a good built true dual will flow better than a single exhaust.
Heavier by what, a pound or two? He could go pee before he drives if he needs a 1 pound weight savings. And I think most people would agree that a good built true dual will flow better than a single exhaust.
Last edited by built91Z28; Apr 15, 2010 at 07:49 PM.
Thread Starter
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
I disagree with you as far as flow goes. It may be a bit heavier but not enough to make a difference. Thank you for your words of wisdom though.
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
Nice work man. I just did my brothers almost exactly like that so I know the amount of work that goes into it. I like how those mufflers tuck up. One question though. When you installed the pipes under the driveshaft, did you have the rear axle hanging down all the way? If not, on a big bump if the back of the car goes up high, the exhaust may hit the driveshaft.

Are those flowmaster mufflers? If so... I'd ditch them.
I like the rest, nice work. 2 2.5>3 in area so... should help.
I like the rest, nice work. 2 2.5>3 in area so... should help.
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Re: Building my own true duals
Way more than just 1 lb. Think about. If 1 pipe & muffler weighs 10 lbs? How much would 2 mufflers & pipes weigh? Ummmmmm....20 lbs? Yes. Double the material = double the weight.GM was cranking out what? 450? 500hp? Horsepower on single exhaust, in the 4th gen F-bodies. So unless your pushing more than that, I don't see the point.
Besides, there are plenty of aftermarket, single exhaust F-bodies cranking out even higher HP numbers. So why add weight when it isn't necessary?
I added weight with my 11" wheels & 315s rear tires, but the additional traction is well worth the added weight!
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Joined: Aug 2001
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
Way more than just 1 lb. Think about. If 1 pipe & muffler weighs 10 lbs? How much would 2 mufflers & pipes weigh? Ummmmmm....20 lbs? Yes. Double the material = double the weight.GM was cranking out what? 450? 500hp? Horsepower on single exhaust, in the 4th gen F-bodies. So unless your pushing more than that, I don't see the point.
Besides, there are plenty of aftermarket, single exhaust F-bodies cranking out even higher HP numbers. So why add weight when it isn't necessary?
I added weight with my 11" wheels & 315s rear tires, but the additional traction is well worth the added weight!

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From: Orlando
Car: 1991 Camaro Z28
Engine: 357, Canfield heads, solid roller,
Transmission: Upgraded 03 Cobra T56
Axle/Gears: 9" 3.50 gears and Detroit Locker
Re: Building my own true duals
Way more than just 1 lb. Think about. If 1 pipe & muffler weighs 10 lbs? How much would 2 mufflers & pipes weigh? Ummmmmm....20 lbs? Yes. Double the material = double the weight.GM was cranking out what? 450? 500hp? Horsepower on single exhaust, in the 4th gen F-bodies. So unless your pushing more than that, I don't see the point.
Besides, there are plenty of aftermarket, single exhaust F-bodies cranking out even higher HP numbers. So why add weight when it isn't necessary?
I added weight with my 11" wheels & 315s rear tires, but the additional traction is well worth the added weight!

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Re: Building my own true duals
Ok so maybe it is more than a pound. 10 pounds still isnt that much. 10 pounds may matter in a dedicated track car, but not a street car. You could take the stero and speakers out to get 10 pounds also. What 4th gen came out with 500 horese power? GM, like every manufacturer, is conserned about making the car quiet with the factory exhaust. So are you saying that all the people on this board with true duals are making their cars worse?
If they are after ultimate levels of power & quick track times? Then the least amount of weight is their goal. I may be going with true duals some day too, because my GTA is a driver & never sees a track.
Don't get me wrong.....I think it is awesome what he built. It is HIS car. If HE is happy with it, that is all that really counts in the end. I wasn't trying to put it down at all.
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Re: Building my own true duals
I use to have the same setup well not the same not a true dual but I hda those same 1 chamber mufflers and I love them loud a s s hell.
Tony.
Tony.
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Re: Building my own true duals
There is a fair bit of the exhaust that is already two pipes anyway, plus one large muffler vs two small ones. I'd say the difference is maybe about 6' of pipe, so thats slightly over 10lb for 16ga 2.5" OD.
There are also 3.5" and 4" single systems floating around out there if that floats your boat. I think a nicely done dual system is a good option though.
There are also 3.5" and 4" single systems floating around out there if that floats your boat. I think a nicely done dual system is a good option though.
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Re: Building my own true duals
Thats sweet.
What would you charge to make me an exhaust like that?
Im in Tampa, too.
What would you charge to make me an exhaust like that?
Im in Tampa, too.
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
LOL! You guys are killing me. I don't know if I can do another one of these since it was so time consuming. My poor 3 yr old daughters eyes must be shot from walking into the garage in the middle of me welding. "AH DADDY MY EYES BURN!"
Re: Building my own true duals
Imagine the cute pictures you'll get with those on her!great work bud... it really looks good!
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
I've got time to wait! Need new exhaust by August when inspection rolls around.. (no emissions here). C'mon, with the money you'll make you can get your daughter some really cool welding goggles... she'll love them!
Imagine the cute pictures you'll get with those on her!
great work bud... it really looks good!
Imagine the cute pictures you'll get with those on her!great work bud... it really looks good!
Re: Building my own true duals
GM was cranking out what? 450? 500hp? Horsepower on single exhaust, in the 4th gen F-bodies. So unless your pushing more than that, I don't see the point.
Besides, there are plenty of aftermarket, single exhaust F-bodies cranking out even higher HP numbers. So why add weight when it isn't necessary?
Remember the rule. For the muffler NOT to be a restriction it must be capable of flowing 2.2cfm/horsepower produced. Otherwise you're leaving power on the table.
It's pretty hard to find an 800 cfm muffler that isn't deafening. Finding two at 400cfm is easy.
Here's an excellent article.
http://www.superchevy.com/technical/...exh/index.html
Nice job by the way.
Last edited by skinny z; Apr 21, 2010 at 07:44 AM.
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Re: Building my own true duals
Think theres enough room to run 3 inch pipe then go to 2.5 over the axle? Since the exhaust cools and slows down I wanted to keep the velocity up. Thanks
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
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From: San Antonio, TX
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Re: Building my own true duals
Thats the best one I've heard in a while lol. Well thats good news I like your setup it looks really really clean. I think I'm gonna have to jack your idea-if you don't mind lol. I tried to 3 inch over the axle on each side of the gas tank but they got crushed into an oval shape by the axle. So I think 2.5 will work better. Nice car btw
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
Thats the best one I've heard in a while lol. Well thats good news I like your setup it looks really really clean. I think I'm gonna have to jack your idea-if you don't mind lol. I tried to 3 inch over the axle on each side of the gas tank but they got crushed into an oval shape by the axle. So I think 2.5 will work better. Nice car btw 
Thanks
If you do it yourself take your time and be patient. There were moments where I thought I bit off more than I could chew but I just did it one section at a time. Re: Building my own true duals
Thread Starter
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
Can the mods add this thread to the stickies please? I'm getting alot of requests for pics of my exhaust and it's easier to just tell them to check the stickies
Thanks.
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Re: Building my own true duals
Theres already a sticky for dual exhaust. Add your pics to it.
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Re: Building my own true duals
curious why you have 2 band clamps on the over the axle pipes when the joints are welded?
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Car: 1991 Camaro Z28
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Thread Starter
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
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Transmission: T56
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Re: Building my own true duals
Ok here's the latest on my exhaust. The flowmaster 10 knockoffs have been canned. Too loud and rattlely. I got me a set of Magnaflow Universals part 10416. They sound AWESOME!!! I bought some Autozone stainless tips but I don't know if I like the look. I think it looks better without the tips. What do yall think?










Last edited by pwdbychevy; Aug 21, 2010 at 10:27 AM.
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Re: Building my own true duals
the tips dont look bad at all!!
i did a true duel system on my car but i was looking for speed not to be pretty. so mine looks like ***. it was the best i could do with long tube headers. lolol
nice job man!!!
i did a true duel system on my car but i was looking for speed not to be pretty. so mine looks like ***. it was the best i could do with long tube headers. lolol
nice job man!!!
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
Thanks yall. I guess I got so used to the dual tips that the single tips look weird to me. I can make the duals work but I would have to perform some surgery on them.
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Re: Building my own true duals
I'm going to go against what the others have said and say no on the tips. But to be fair, I dont really like tips in general. I say if you do want to run them, cut them down so they sit atleast flush with the bumper if not tucked in a little.
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: Building my own true duals
I hear ya. I just slipped them on to get an idea. I don't like the kinds that are held on with bolts anyways. They loosen up after a while. I decided I'm going to perform surgery on the dual tips.
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Re: Building my own true duals
i think some 3.5" slash cut tips would look really good on there.
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Re: Building my own true duals
i'd also really like to hear it if you get a chance, also look good either way it's a nice car.















