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True Duals, questions answered here. Post YOUR information and pics too!

Old 06-26-2006, 08:32 AM
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Cool True Duals, questions answered here. Post YOUR information and pics too!

True Dual FAQ

Got some information to add that you don't see here? Post up!

Q. What are true duals?
A. Exhaust that comes off each header and goes into an X, H pipe and then has 2 pipes that run all the way out to the exit of the exhaust. Factory exhaust is a Y setup where the stream from each header are merged into a single pipe,

Q. What kind of gains can I expect with true duals?
A. If you have stock exhaust you will pick up around 30HP by going to duals with a set of headers. If you already have headers and a cat-back, don’t expect a big gain, but some are to be had if the catback is very.

Q. What are the benefits of duals?
A. Many people believe that duals sound much better than cat-backs. I personally believe that a good dual setup sounds better than any cat-back I have heard. That is the main benefit of duals since they yield similar power gains with y-pipes and duals take bit more work to get to fit.

Q. What is better, X or H pipe?
A. Typically the X is known to put out slightly more power than H pipes, but not by much. The H pipe is known to have a better sound to it. You can’t really go wrong with either.

Q. What does dumped or dumps mean?
A. This refers to whether or not the exhaust is run all the way out the back of the car or not. Dumped means that the pipe exit is located underneath the car, usually right before the rear axles. Dumps are pretty loud and have some drone to it, but can be gotten used to.

Q. Can I have duals and have the pipes ran out the back where the factory pipes were?
A. Yes. It can be done but it usually is a bit expensive to get the pipes ran out the back. This is due to it being fairly difficult to get both pipes over the axle because it is very space limited up there. There are setups that have both pipes going over the passenger side on the rear axle and there are setups that have one pipe over the driver axle and the other pipe goes under the axle. Also, you can buy a new upper PHR to help running 2 pipes over the passenger side of the rear end (see post#2).

Q. Can the pipes be ran under the axle?
A. Yes, the pipes can also be run underneath the axle successfully with enough clearance. Clearance under the rear end is usually no worse than anywhere else in the system. The suspension unloading causing the swaybar to contact the duals is the only concern and usually not a problem. Using 3-bolt flanges for under-axle setups will allow for pipe removal if the rear end should be dropped.

Q. What kind of ground clearance will duals give me?
A. Duals usually will sacrifice a little ground clearance. It really depends on how custom they were designed as well as how well they are tucked up. I have seen some where they are very close to the ground and others that are almost at stock height. My duals are tucked up far and I never hit them, I scrape my headers before I scrape the duals. Ground clearance will also depend on the size of the pipes you use.

Q. What size piping should I go with?
A. The most common sizes for duals are 2.5” and 3”. The general rule is that if plan on lowering your ride, go with 2.5”, if you are going to stay at stock height go with 3”. Anymore than 500HP and you will probably want to go with 3", unless lowering takes priority. There are lowered cars that run 3” with no problems. Both sizes will support plenty of power, more than almost all of us will likely make.

Q. What are my choices of mufflers for duals?
A. There are quite a few mufflers that work well with duals. Most people use a bullet style muffler with duals which is placed between the X junction and the axles. Some people use single chambered mufflers instead of bullets. The bullets will usually offer the best ground clearance. In setups that go over the axles, the mufflers can also be placed behind the axles. The most common bullet mufflers used are, dynomax and moroso spiral flows. The more common chambered mufflers are flowmaster single chambers and sweet thunders.Borla XR-1 mufflers are good, as are Maganflow 3" core bullet mufflers. Sweet Thunder chambered mufflers "neck down" and reduce flow. Powerstick mufflers are the same basic design but don't neck down. Only available in aluminiumised steel. Stainlees Works offers something similar in stainless steel. Flowmaster 10 Series mufflers are also worth a look.

Q. Can I run cats with duals?
A. Yes. I run gutted ones just in case the cops ever check. My ground clearance is still good too. You want cats that support the exhuast flow such as Magnaflow's carsound cats. For more powerful setups Metal Matrix CATS are the only sensible option. Random Technology (7000 Series) and Magnaflow offer them, again in 3" core.

Q. How much does a dual setup cost?
A. It varies a lot. For just a dumped setup with mufflers and no cats look to spend around $400. It depends on the mufflers you choose too. They can be had for less, check around at your local muffler shops for prices. If you plan to go over the axle and out the back it gets more expensive. Some shops charge only a few hundred to extend the pipes out over the axle but I have seen shops that charge over $600 easy to go over the axle. Under the axle isn’t too expensive. Once again, ask around at local exhaust shops.

Q. What are mandrel bends?
A. This refers to how the pipes are bent. Mandrel bends stay the same diameter in the bends that the pipe is in the straight sections. Non mandrel bent pipes are crushed in the bends, which can choke flow a little.

Q. Should I have mandrel bends?
A. Probably, why spend the money and not have it done right IMO?

Q. Should I use mild steel or stainless steel?
A. It depends. Mild steel rusts out after a while, while stainless will last forever. I think it depends on where you are located. If you are in somewhere like Florida mild should be fine but if you are in upstate NY where it snows and is cold I would get stainless. Stainless is typically a bit more expensive than mild, although I have seen places do stainless dumps for $400-$500.

Q. Do I have to run LT's with true-duals?
A. Maby. The TSP duals system is mean to mate up with LT's (Pacesetters, QTP's, etc.), but can be modified to fit manifolds with some work (welder, pipe, reducers, flanges). The Bassani system is meant to bolt up to stock stuff and doesn't require any. This system can also be used with LT's by doing some modifications. Custom true-duals can mate up to the headlights if you wanted them to.

Q. Will I have torque arm problems?
A. This answer depends on each individual setup. Some TQ arms will not while others sometimes do. Body mount TQ-arms are extremely hard to work. The TQ arm is not always the limiting factor in clearance. Sometimes the duals are built in such a way that they BARELY clear the factory TQ arm. Lowering the car brings the TQ arm up a bit, and might offer a slight bit of extra clearance. UMI Performance makes a torque arm specifically for this purpose. You can find pictures of it and links to more information courtesy of Ryan@UMI if you scroll down.

Q. What about my tunnel brace (aka driveshaft saftey brace) and my options for driveshaft safety loops?
A. You can remove the factory tunnel brace if it becomes a problem, this is a must on TSP duals setups. Driveshaft safety loops are hit-or-miss, with most being miss. Do a search on some setups in here and in the suspension forum to find more info. Some people report good luck with the Lakewood units.

Q. Can I remove the transmission with true-duals?
A. Maby. TheBlurLS1 has removed his several times with TSP true duals. The rear hangers had to be unbolted to allow the engine/trans/exhaust to told and open up access to the top bolts, but the rest of the system was still intact and clamped to the headers. Some systems are built in such a way that it won't allow it, but most should not have a problem.



I personally love true duals and think they sound awesome. I will never go to a cat-back setup. My setup spiral flows and they are tame when just cruising but get loud and mean when I get on it. I have it tucked up real good so I think it has close to the same clearance that a y-pipe would get. Remember that duals are not going to net you tons of peak power over a cat-back setup, although they are known to help with low end power under the curve due to scavenging effects. The main reason for duals IMO is for the sound.

Guys feel free to add anything you wish to this FAQ, I hope it helps you guys out that are interested in duals.

Pictures!

Please post up if you have links to them. If you don't, host them on tinypic.com (or photobucket etc.) and post the URL's with IMG tags (imbedded pictures like below), or post links to the pictures.

02SS:ZEUS - Over the axle TD's.
TheBlurLS1 - Under the axle TD's.
Want more clearance? By W8S SS - https://ls1tech.com/forums/generation-iii-external-engine/678183-anyone-looking-more-height-their-tsp-td-s.html#post6685132

Last edited by TheBlurLS1; 03-20-2007 at 02:30 AM.
Old 06-26-2006, 12:28 PM
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here is mine, been posted before

true duals, 3in to the inlet of the x-pipe, and 2.5 out back through 2 magnaflow 4in round mufflers, i will get some sound clips this weekend.....because i have been slacking for over a year now on them

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More Pics:

http://i5.photobucket.com/albums/y16...5/IMG_0482.jpg
http://i5.photobucket.com/albums/y16...5/IMG_0480.jpg

Last edited by TheBlurLS1; 07-05-2006 at 03:57 PM.
Old 07-02-2006, 02:13 AM
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Here it is:
2.5" Stainless steel Bassani True duals. It's all tucked. Enjoy!


This is a shot of the lowest point of the exhaust. Lowered with DMS springs... I have about 2-3" from the ground to the bottom of my lowest pipe.




Here is what my Bassani TDs sound like... Take it for what its worth.


Bolt ons:http://youtu.be/YnUeofOr84Q

Heads and cammed: http://youtu.be/sz6RBJFjn4o
New video.

Last edited by bene; 07-21-2012 at 05:32 PM.
Old 07-02-2006, 01:01 PM
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This is my setup: 2.5" all the way, H-pipe, Sweet Thunder mufflers under the axle. My clearance is awesome, more than I had stock. Cost me $480.00 for the duals installed. That includes the mufflers, H-pipe, mandrel bends to the H-pipe, tips and all hangers. There are flanges behind the mufflers so I can run dumped or take the tail pipes off for maintenance.

Sound is amazing......not too loud at normal cruising but very loud and aggressive at WOT. Much better compared to my dumps. No drone or rasp whatsoever. I compare the sound to Hooker.....but much louder and deeper. Very noticeable gains when these and the headers went on. My times at the track went from 13.62 @ 103 to 12.98 @ 107.7. She trapped a highest of 108.5 on a 13.0 run.

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EDIT: I recently swapped for a traditional exhaust setup. I went to a ORY with a new SLP Dual/Dual I was able to score because the duals were just too loud after the cam install. I miss the duals sometimes, but the D/D sounds awesome and very tame. When I want wild, I have a DMH e-cutout that sounds absolutely wicked when opened.

Last edited by 99Hawk262; 08-17-2008 at 01:15 PM.
Old 07-04-2006, 09:58 PM
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I just wanted to add a note- Our transmssion mounted torque arms will clear with virtually any true dual system that dumps before the axle. Our torque arms actually add addtional clearance to allow the exhaust to be tucked up tighter to the floor then what the stock torque arm will allow. I posted a picture below showing the installation of a TSP system, if anyone would like to see more pictures please visit this link- http://www.umiperformance.com/2205.aspx

Wondering about the TQ arm relocation (new tranny cross-member)? The TSP system will clear fine with our torque arm relocation kit. I am sure many other custom true dual systems will as well but we can 't guarantee it with out pictures. Or we recommend the buyer to look at our installation pictures on our web site and compare them to there vehicle to confirm fitment.


Last edited by TheBlurLS1; 07-05-2006 at 03:09 PM.
Old 07-07-2006, 11:33 AM
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Default True Duals into a CME?

Anyone done this? pic's?

I have a local muffler guy that i will have fab me up a system..

Should look/sound awesome with my H/C set up...

I am currently running my true duals out the back...
Once i install the CME set up.. these tips & pipes will be f/s if anyone is interested... they mount right up to my Lanes true duals & run under the axle with Magnaflow 4in tips...

Any comments/ pic's would be appreciated.




Last edited by TheBlurLS1; 07-07-2006 at 12:53 PM.
Old 07-10-2006, 11:58 AM
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Copy... Paste...
Also, click pics for higher resolutions
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Old 07-25-2006, 01:09 PM
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Here are my custom duals. Paid $500 for them.





Last edited by badaz28; 07-25-2006 at 09:26 PM.
Old 07-26-2006, 10:26 AM
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Old 08-02-2006, 02:30 PM
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This is from my LT1 that I just sold.

It was custom made with maglaflow.

Te tube hits the driveshaft as you can see.



Old 08-19-2006, 03:15 PM
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Here's what the ones I build look like.
Old 08-19-2006, 07:33 PM
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True Dual Pics.. I need to get some pics that are actually under the car.. Enjoy

Pics Of My X Pipe

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Pics Of My H Pipe

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Videos!

X Pipe




H Pipe The First 3 Vids Are B4 My Cam.









Last edited by TORCHD 02 TA; 10-31-2007 at 10:26 PM.
Old 08-20-2006, 05:35 PM
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I just got custom true duals the other day.
From a muffler shop named Phils in north Fort Worth.
I brought him the 2 10 series flowmasters, cutouts, and x pipe. He also reused my stock tips.
He only asked for $275, but I gave him $300 cuz it just looks/sounds so damn good!!








2 videos of my car


outside the car
inside the car

Last edited by TheBlurLS1; 09-03-2006 at 12:18 AM.
Old 08-30-2006, 04:23 PM
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here's me setup:

pacesetter lt's, 3" piping, and x-pipe, with bullits

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sound clip link:




the body shop had to repaint my bumper already (on them) b/c the paint was wearing through (they sprayed too thin). and the exhaust was a complete custom tailored job that cost a very, very pretty penny. thinking about switching to sweet thunders though, but i havent heard them in person yet, its loud, but just not quite the sound i was looking for....regardless, it sounds amazing and i love

oh and i live in CA,

CATS? **** !CATS!


Edit: links fixed; just realized the pics were down

Last edited by SIK02SS; 06-22-2007 at 04:19 PM.
Old 08-30-2006, 08:43 PM
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looks good im diggin the tips too.. are those them ebay stainless tips? looks good.. just a lil too loud for me thow..IMO i love the way the true duals sound with 3" magnaflow bullets..ive herd them in person and fell in love..if i ever get headers and some extra cash thats what im gettin ..
Old 08-31-2006, 11:15 AM
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Originally Posted by slimcracka
looks good im diggin the tips too.. are those them ebay stainless tips? looks good.. just a lil too loud for me thow..IMO i love the way the true duals sound with 3" magnaflow bullets..ive herd them in person and fell in love..if i ever get headers and some extra cash thats what im gettin ..

thanks, and yea they're from ebay. pretty good tig welds too, layed a consistant bead. its kinda loud, but my 1st setup was a side exit wtih ZERO clearance and i'm used to hearing it right next to my head so its a bit quieter sounding to me. and the pitch isnt what i really care for, so i'd like to hear my friends Z28 with the STs and maybe switch. its real deep sounding and i want a little more throaty..
Old 08-31-2006, 08:14 PM
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Originally Posted by slimcracka
looks good im diggin the tips too.. are those them ebay stainless tips? looks good.. just a lil too loud for me thow..IMO i love the way the true duals sound with 3" magnaflow bullets..ive herd them in person and fell in love..if i ever get headers and some extra cash thats what im gettin ..

that is what i am running (see sig) that is not what i am looking for as far as sound.. i need to get my lts on and go from there

Originally Posted by SIK02SS
thanks, and yea they're from ebay. pretty good tig welds too, layed a consistant bead. its kinda loud, but my 1st setup was a side exit wtih ZERO clearance and i'm used to hearing it right next to my head so its a bit quieter sounding to me. and the pitch isnt what i really care for, so i'd like to hear my friends Z28 with the STs and maybe switch. its real deep sounding and i want a little more throaty..
have you heard my car yet?? scroll up a little bit and i have to sound clips.but i know what you mean on the tone.. i am not happy with mine either.. I need to get my LTs on and go from there otherwise i might do H with 1 chamber flows. or maybe switch out my magnapacks and do ST or Flo Pro or Spirla Flo not to sure yet..

BTW are those the magnapacks you are running to??
Old 09-03-2006, 12:21 AM
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It is CLEANNNNNNNNNNNNNNNNNNNNNNNNNN!!
Old 09-03-2006, 12:29 PM
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https://ls1tech.com/forums/showthrea...49#post5466749
TD's and G5 cam
Old 09-04-2006, 02:00 AM
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Originally Posted by TORCHD 02 TA
that is what i am running (see sig) that is not what i am looking for as far as sound.. i need to get my lts on and go from there



have you heard my car yet?? scroll up a little bit and i have to sound clips.but i know what you mean on the tone.. i am not happy with mine either.. I need to get my LTs on and go from there otherwise i might do H with 1 chamber flows. or maybe switch out my magnapacks and do ST or Flo Pro or Spirla Flo not to sure yet..

BTW are those the magnapacks you are running to??


you just need to get some LTs man, that cat back-esque sound on top end is from the manifolds. i'm running dynomax bullit mufflers.

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