[Ghost Ridin]

I was speaking to someone at a muffler shop today and they said that if I wanted to put duals on my NItro (not true dual, just 2 different exaust pipes AFTER the muffler) then I would lose power. They said that changing the muffler, and keeping it to only 1 outlet would be better for hp and gas milage. Any thoughts?

 

[Florida Roadie]

I was speaking to someone at a muffler shop today and they said that if I wanted to put duals on my NItro (not true dual, just 2 different exaust pipes AFTER the muffler) then I would lose power. They said that changing the muffler, and keeping it to only 1 outlet would be better for hp and gas milage. Any thoughts?

Let's say I agree but also disagree. My slant is this. To re-route the second pipe in the fashion needed to achieve the dual exhaust with the many turns required actually restricts the exhaust flow . That's the limit to agreeing with your statement .Installing the muffler with the least restrictive function ( Baffles/chambers ) regardless of noise created and also the RESONATOR removal will achieve minimum back pressure .Aside from having dual headers the optimum is to also remove the cat. converter. Just my .02 worth.

Florida Roadie :Racing:

 

[StarBandit]

The more free flowing the exhaust the less back pressure. You want a certain degree of back pressure otherwise you lose your low end torque. Once the low end torque is reduced, you put more foot into the pedal to achieve the same speed at take off from a stop. That is where you lose mpg, especially in city driving.

On the positive note, if you drive mostly freeways, you'll gain a very small amount of mpg due to the free flowing exhaust. It will mostly be in the .x range and not the x.x range.

From the system you describe, I don't think your loss of either back pressure or mpg will be significant since it's after the same muffler for both pipes. The Gibson daul catback is such a system. I personally am opting for the single catback, as with the Magnaflow catback.

 

[808NITRO]

floooooooow

^I agree with them :bananalama:

It also depends on which motor you have.
I went with the single out, does the job haha

 

[Bondsmanla]

I went with the Magnaflow muffler that comes in the catback system and removed resonator better sound and MPG at less the cost of catback system you get great sound both ways but I know for sure more mpg and that is in x.x range for me about 1.2 to 1.5 depending on the right foot

 

[StarBandit]

I went with the Magnaflow muffler that comes in the catback system and removed resonator better sound and MPG at less the cost of catback system you get great sound both ways but I know for sure more mpg and that is in x.x range for me about 1.2 to 1.5 depending on the right foot

Did you go welded pipe or clamp? I had thought about doing the same with just getting the muffler and pipe to ditch the resonator and adding a chrome turn down end with just enough showing to know it's there. Do you have the part number for the muffler from the catback system? The system is 16702 or something like that but did not see the muffler itself.

How is the sound? Is it more tuner car or muscle car? With the V6 it should still have a deep tone if the chamber and baffle placement is correct. I've also thought about the Flowmaster series but don't want an interior noise level at idle or at highway speeds. Mostly when I romp on it is when I expect the sound (if that makes sense).

 

[TylerCanada]

This is not entirely true. Backpressure is bad, but you need good exhaust velocity for torque. It's due to the scavenging effect. If the exhaust gases are travelling fast enough, they will pull along more of the exhaust in the cylinders and pull a bit more fresh air in.

Backpressure was needed in the days of carburetors, but not with electronic fuel injection. The ideal system is small enough diameter piping for good velocity, with minimal backpressure. Given that a dual exit muffler on a single pipe exhaust system reduces backpressure but doesn't affect velocity (only the single pipe diameter affects that), it would probably slightly increase power.

The more free flowing the exhaust the less back pressure. You want a certain degree of back pressure otherwise you lose your low end torque. Once the low end torque is reduced, you put more foot into the pedal to achieve the same speed at take off from a stop. That is where you lose mpg, especially in city driving.

 

[HighVoltageNITRO]

The short answer to your question is no. I don't think you want a short answer. I think you could be chasing demons that don't exist. I have duals as you describe, but I am not about to try to convince you to go that way. Exhaust is a personal preference that you have to live with daily.

I watched and listened as my muffler shop tried different mufflers on the Nitro. In the end they started it up without any muffler. These vehicles are not that loud without a muffler. They need a muffler because they are harsh and raspy without one, not because they are loud. I can't possible know what you have heard in your life as a reference, but there is no comparison to the magnitude of sound volume of a Nitro compared to a 5.7 L V8 with, lets say, glass packs.

I am telling you this because while the stock muffler and resonator are somewhat restrictive, you need to understand that so are the stock catalytic converters. I wouldn't dare suggest doing anything with them. I only remember one forum member that ripped off his converters, but he was driving a lot off road.

What you do with the muffler should be done for your satisfaction only. Period. A muffler change will not dramatically change your mileage one way or another unless it makes you stand on it more because you like the sound.

Performance is a different story. I have the R/T. What I noticed immediately upon installing the exhaust was the engine spins up faster. For me, this made the change worth it.

Sounds. I chose to go with duals because I favor the stereo sound you get from dual pipes. I wanted some harmony, not just a loud exhaust. For 8 months, I had a Flowmaster on mine. I began to experience more resonance than I liked, so a week or so ago I had it replaced with a Magnaflow. The sound at idle is about the same between the two. However, above 2800 rpm, the Flowmaster begins to get it with a little burrpp (tuner sound) resonance that diminishes around 4000 rpm. The Magnaflow is melodious right up through these same rpm ranges and peaks with a pleasing roar about 3/4 as loud as the Flowmaster. Another difference, my wife likes the Magnaflow and hated the Flowmaster.

If you are wanting to change your exhaust for the small performance increase and not so much for the sound then you might want to consider a Borla to replace the stock muffler and ditching the resonator. Borla will not be that much louder than stock. If you want volume increase, remove the resonator and drive around with the stock muffler for a while before you do anything else. At least that will give you a base line from which go when you do change your muffler.

You also might want to find a different shop. Could be they just didn't want to take the time to install duals because they have to make the crossover. Whatever you do, you are the only one that needs to be satisfied with the results.

 

[BIG RED]

DUAL EXHAUST
Can anyone tell me which is the best sounding Dual Exhaust system for my R/T 4.0? I have read all the posting and would like to know what the consensus is.

 

[KenCary]

Let's say I agree but also disagree. My slant is this. To re-route the second pipe in the fashion needed to achieve the dual exhaust with the many turns required actually restricts the exhaust flow . That's the limit to agreeing with your statement .Installing the muffler with the least restrictive function ( Baffles/chambers ) regardless of noise created and also the RESONATOR removal will achieve minimum back pressure .Aside from having dual headers the optimum is to also remove the cat. converter. Just my .02 worth.

Florida Roadie :Racing:

Roadie,

I respect your lack of interest in the dual outlet set up that many of us have, but it is not any more restrictive than the alternatives.

You are dead wrong on the routing of the second pipe. Even with the two 90 degree bends more than 70% of the orginal diameter is still open (you need to bend with heavy guage pipe.) In my case the straight pipe is 2 1/4", and the bent one is also 2 1/4". The pipe coming off the cat is only 2 1/2. Even if 50% of the bend pipe was blocked, this is provides far more flow than a single 2 1/2" pipe.

Here is the math:

Single 2 1/2 outlet: 3.14 X (2.5/2)squared = 4.90 Sq"

Dual outlets 3.14X (2.25/2)sqared = 3.97 Sq" + 3.97 X .7 = 3.97 + 2.78 = 6.75 Sq"

My set up has aqt least 37% more outlet area than coming in to the muffler. Even though the second exhaust has to flow through a couple of bends, this is still very open.

Also understand that the culprit in the Nitro exhaust is the muffler and resonator, not the pipes after the mufler.

Change out the stock muffler, dump the resonator and you will pretty much get the same kick as a cat back exhaust without the cost.

Lets get real here, a 3.7 or 4.0L V6 even at 100% volumetric efficiency will probably flow under 400CFM no need for monster pipes here. Also as mentioned before, true duals on a street V6 like this WILL reduce low end torque unless you add a crossover pipe.

 

[Florida Roadie]

Roadie,

I respect your lack of interest in the dual outlet set up that many of us have, but it is not any more restrictive the alternatives.

You are dead wrong on the routing of the second pipe. Even with the two 90 degree bends more than 70% of the orginal diameter is still open (you need to bend with heavy guage pipe.) In my case the straight pipe is 2 1/4", and the bent one is also 2 1/4". The pipe coming off the cat is only 2 1/2. Even if 50% of the bend pipe was blocked, this is provides far more flow than a single 2 1/2" pipe.

Here is the math:

Single 2 1/2 outlet: 3.14 X (2.5/2)squared = 4.90 Sq"

Dual outlets 3.14X (2.25/2)sqared = 3.97 Sq" + 3.97 X .7 = 3.97 + 2.78 = 6.75 Sq"

My set up has aqt least 37% more outlet area than coming in to the muffler. Even though the second exhaust has to flow through a couple of bends, this is still very open.

Also understand that the culprit in the Nitro exhaust is the muffler and resonator, not the pipes after the mufler.

Change out the stock muffler, dump the resonator and you will pretty much get the same kick as a cat back exhaust without the cost.

Lets get real here, a 3.7 or 4.0L V6 even at 100% volumetric efficiency will probably flow under 400CFM no need for monster pipes here. Also as mentioned before, true duals on a street V6 like this WILL reduce low end torque unless you add a crossover pipe.

Ken I have the Flowmaster 40 series single exhaust .I still believe this is every bit as efficient at eliminating back pressure as having the same muffler but with dual exhaust pipes .According to the muffler expert that installed my system ,and a very long time race car builder , NO gain by having dual pipes .Other than a changed sound and dual pipe appearance . In fact his opinion is that the existing resonator has little restriction. Granted there are mufflers out there that are better at reducing B pressure ,like the Flowmaster 44 series but interior noise penetration is to be expected .As far as the dia. of the pipe is concerned also to be considered is the configuration of the pipe. It's a gimme that straight pipes are best at achieving what we are discussing. The sooner out the pipes end the better .Every turn reduces velocity .If and when a header system is produced for the 4.0 I'll add it and a CAI .Otherwise I'm very content with the all around product of the set up I now have .My Friend I guess that's why they make Chocolate and vanilla.

Roadie .:Racing:

 

[KenCary]

Ken I have the Flowmaster 40 series single exhaust .I still believe this is every bit as efficient at eliminating back pressure as having the same muffler but with dual exhaust pipes .According to the muffler expert that installed my system ,and a very long time race car builder , NO gain by having dual pipes .Other than a changed sound and dual pipe appearance . In fact his opinion is that the existing resonator has little restriction. Granted there are mufflers out there that are better at reducing B pressure ,like the Flowmaster 44 series but interior noise penetration is to be expected .As far as the dia. of the pipe is concerned also to be considered is the configuration of the pipe. It's a gimme that straight pipes are best at achieving what we are discussing. The sooner out the pipes end the better .Every turn reduces velocity .If and when a header system is produced for the 4.0 I'll add it and a CAI .Otherwise I'm very content with the all around product of the set up I now have .My Friend I guess that's why they make Chocolate and vanilla.

Roadie .:Racing:

You just wasted a post to say that you agreed with me.

like I said, the dual outlet set up is no more restrictive that the alternatives. It will not cause a lack of power over a single pipe. Like I also said, this is no race motor.

As High Voltage Nitro Mentioned, there is a different sound with dual outlets. and some of us like the sound as well as the look.

 

[Florida Roadie]

You just wasted a post to say that you agreed with me.

like I said, the dual outlet set up is no more restrictive that the alternatives. It will not cause a lack of power over a single pipe. Like I also said, this is no race motor.

As High Voltage Nitro Mentioned, there is a different sound with dual outlets. and some of us like the sound as well as the look.

Ken ..Communication between folks is never wasted . :shakehead: I feel better already just knowing that we DO agree.I never said that duals lost power .That was someone else. What I said was that pipes that have turns and bends slow velocity and it does. Even back in the days when I juiced a 49 Ford 8BA flathead we lost the muffler totally ,dropped the straight pipes below the axle level so that the pipes had absolutely 0 restriction and straight out the back.. Engines have changed many times over but the combustion engine is still exactly that .An air processing machine .The more in and the faster out along with the proper fuel mix is still the goal.

 

[kaleos]

vvvvvrrrrrroooooommmmmmm!!!!!!!!!!!!!!!!!!!!!!!

You just wasted a post to say that you agreed with me.

like I said, the dual outlet set up is no more restrictive that the alternatives. It will not cause a lack of power over a single pipe. Like I also said, this is no race motor.

As High Voltage Nitro Mentioned, there is a different sound with dual outlets. and some of us like the sound as well as the look.

Ken ..Communication between folks is never wasted . :shakehead: I feel better already just knowing that we DO agree.I never said that duals lost power .That was someone else. What I said was that pipes that have turns and bends slow velocity and it does. Even back in the days when I juiced a 49 Ford 8BA flathead we lost the muffler totally ,dropped the straight pipes below the axle level so that the pipes had absolutely 0 restriction and straight out the back.. Engines have changed many times over but the combustion engine is still exactly that .An air processing machine .The more in and the faster out along with the proper fuel mix is still the goal.

hello florida roadie............i agree with you sir on all that you have said. i also agree that all that you say is never wasted. i also agree that anything that anybody else says is never wasted. but i do agree that what "I" keep mumbling about may be wasting somebodies time.:chuckle::chuckle:

as for the muffler system, as hvn said, it's basically up to the individuals preference. i have the flowmaster 40 series with the resonator off and using the original exit pipe. midas muffler installed mine. it's not a beautiful system underneath, if i wanted this i would have got all s/s. it is loud enough for me and the fuel mileage may be up 1 mpg more but its the pickup at high speeds is what i have noticed. i may just have a heavier foot and alittle extra wind behind me at the time but its noticeable.

good luck to all that attempt to bring out the beast in their nitro!!!!!

mcnabb (kaleos) in louisiana................