[gixxer160]

HI. I just went to a true dual setup using a pair of Aero Turbine AT2525 mufflers. I researched many of the performance shops here and it was the general consensus that an X pipe or an H pipe would not be needed if the performance was there.
I am happy to say that they were correct. The performance is there, the sound is awesome, the fuel mileage is a little better too. A couple of things that surprised me were, virtually no drone at 60 mph on the hwy or in the city. At idle it is very quiet too, quieter than the 14" Magna flow I had on before. I am very pleased that this upgrade went so well. I would highly recommend this to anyone that wants an awesome sounding system, and cheap too.
Do not be fooled into thinking you need an X pipe or H pipe, it just isn't so.

 

[chefred112]

to each his own man...if you feel you don't need it, don't let the guy in a 12.x ram convince you otherwise , I've done searches on this with seems like every mfg type of car out there and almost to a man I've haven't read anyone say 'don't do it'....must be alot of misinformed people out there with really fast cars

 

[gixxer160]

The cars would be just as fast without an X or H pipe. Just because they have it doesn't necessarily mean they go any faster, than if they didn't. But like you said, to each his own. Try it before you knock it.

 

[chefred112]

Try it before you knock it.

exactly, since you're tellin everyone not to do it and you haven't tried this route

 

[CdnoilRAM]

You'll just have to believe me when I tell you that a crossover of some kind makes a big difference in flow as well as noise output. Yes an H- or X-pipe will reduce noise levels but the reason you want them is for the scavenging effect you get between the banks. I had a completely isolated true dual system when I first had the exhaust installed and then in my quest to reduce the volume I added an H-pipe before the mufflers where the two pipes came together. After just the H-pipe install (and 2 bungs) I dropped 1.5psi on my boost gauge which means there's better flow through the engine, less back pressure, and more power.

But what do I know, I've only tried both on the exact same truck

 

[gixxer160]

Perhaps the difference is the type of Muffler used. The Aero Turbine is a muffler that sucks the exhaust gas out, I believe it helps pull the exhaust gas out from the engine. Check the Aero web site for more info.
All I can say is that they work, and work very well. They are unlike any other muffler.

 

[chefred112]

Aero has been around many many years..I considered buying them until i rode with a buddy who ran them... I must be getting old cuz I'd rather hear the loud on the outside...not on the inside..

 

[gixxer160]

Your post doesn't make any sense. You buy a loud exhaust so you can hear it, inside and out. The beauty of the Aero is that when you drive like a sane person, you don't get all the drone and noise, only when you put your foot into it does it come alive, which is what you want. Which is what I said in my original post.

 

[chefred112]

I endured 'loud' for about 3 years...sometimes my ears would ring when I use to get out of the truck because it was loud... it was embarrassing having passengers because you would always have to raise your voice to be heard so I wanted options. I wanted my truck to sound muscular, not loud when I switched up my exhaust. Now, 90 percent of the time I drive around with the muscular tone I was looking for..and the other 10 percent when the kid of me wants to come out, I flip a switch and my truck sounds like nascar and you could feel the ground reverberate...

 

[CdnoilRAM]

Perhaps the difference is the type of Muffler used. The Aero Turbine is a muffler that sucks the exhaust gas out, I believe it helps pull the exhaust gas out from the engine. Check the Aero web site for more info.
All I can say is that they work, and work very well. They are unlike any other muffler.

There is a big difference between the AT design and a proper exhaust that uses the exhaust pulses to scavenge flow. The AT design does create a lower pressure in the chamber around the main flow, the downside is that low pressure flow still needs to join up with the main flow again, and it does it at a lower, almost static, speed so it's actually slowing the outflow down. I've also seen the aero website, but my education as an aerospace engineer gets me past some of the marketing bs.

The reason the AT is designed the way it is is to use the exhaust pulse to dampen frequencies without the need for insulation, and it does that fairly well, but it's still not a great muffler, performance wise, when compared to a perforated tube surrounded by insulation. The AT can't scavenge as effectively as an x-pipe/perforated design will because it doesn't maintain the exhaust velocity as well.

Now, you are happy with your system, and that is what matters, but it is incorrect to say that crossovers aren't needed.

 

[SD70M2]

What did you do for o2 placement?

 

[gixxer160]

I kept the stock header for now, and also the stock cats. The O2 sensor's were not affected. Just straight dual from the stock headers back.

 

[SD70M2]

Copy, I'm looking to plumb in my sidepipes so I'm trying to get a leg up before I start.

 

[gixxer160]

I will be changing my headers this fall. I will be eliminating the cats and with my Diablo T1000 setting up a new program with the help of the local dyno shop.

 

[HammerHead]

You'll just have to believe me when I tell you that a crossover of some kind makes a big difference in flow as well as noise output. Yes an H- or X-pipe will reduce noise levels but the reason you want them is for the scavenging effect you get between the banks. I had a completely isolated true dual system when I first had the exhaust installed and then in my quest to reduce the volume I added an H-pipe before the mufflers where the two pipes came together. After just the H-pipe install (and 2 bungs) I dropped 1.5psi on my boost gauge which means there's better flow through the engine, less back pressure, and more power.

But what do I know, I've only tried both on the exact same truck

I agree form the research I've done. That's why NASCAR cars use them and there the fastest cars on the track.

 

[gixxer160]

You so,so wrong. Very few race cars use them. What about Vipers and corvettes that use sidewinder pipes. Also what about drag cars and formula cars, drag bikes, twin cylinder bikes.
I have done well over 2500 dyno runs on my race bikes over a 5 yr period. I built my own race exhausts, with a variety of combinations, the best and most performance came from a straight dual set up. As far as I know NASCAR race cars use a dual plane crank as a posed to a single plane crank, that's is why they don't run X pipes. Do you know the difference between a single and dual plane crank ?. There are so many variations in engine design and firing order.
On the 1500 5.7 Hemi you do not need an X or an H pipe and that is a simple fact. But if you want to keep thinking that an X pipe is needed on your vehicle then go ahead, spend the your money. Put your truck on a dyno, with before and after results and post them, lets see the results.

My truck will be on a Dyno sometime in August, so I will post my results then too. Lets compare.

 

[dustin72]

You so,so wrong. Very few race cars use them. What about Vipers and corvettes that use sidewinder pipes. Also what about drag cars and formula cars, drag bikes, twin cylinder bikes.
I have done well over 2500 dyno runs on my race bikes over a 5 yr period. I built my own race exhausts, with a variety of combinations, the best and most performance came from a straight dual set up. As far as I know NASCAR race cars use a dual plane crank as a posed to a single plane crank, that's is why they don't run X pipes. Do you know the difference between a single and dual plane crank ?. There are so many variations in engine design and firing order.
On the 1500 5.7 Hemi you do not need an X or an H pipe and that is a simple fact. But if you want to keep thinking that an X pipe is needed on your vehicle then go ahead, spend the your money. Put your truck on a dyno, with before and after results and post them, lets see the results.

My truck will be on a Dyno sometime in August, so I will post my results then too. Lets compare.

Dual plane crank? You obviously don't know much about engines.

 

[CdnoilRAM]

You so,so wrong. Very few race cars use them. What about Vipers and corvettes that use sidewinder pipes. Also what about drag cars and formula cars, drag bikes, twin cylinder bikes.
I have done well over 2500 dyno runs on my race bikes over a 5 yr period. I built my own race exhausts, with a variety of combinations, the best and most performance came from a straight dual set up. As far as I know NASCAR race cars use a dual plane crank as a posed to a single plane crank, that's is why they don't run X pipes. Do you know the difference between a single and dual plane crank ?. There are so many variations in engine design and firing order.
On the 1500 5.7 Hemi you do not need an X or an H pipe and that is a simple fact. But if you want to keep thinking that an X pipe is needed on your vehicle then go ahead, spend the your money. Put your truck on a dyno, with before and after results and post them, lets see the results.

My truck will be on a Dyno sometime in August, so I will post my results then too. Lets compare.

You are now comparing engines that have completely different operating RPM ranges. High RPM engines don't have to worry about scavenging as much as a lower rpm vehicle because the exhaust flow velocity is so much higher at high rpm because of the sheer volume of exhaust gas that's being evacuated through the exhaust manifold and the biggest priority then is to get it to atmosphere ASAP to remove ALL back pressure, which is why most have short exhausts or are just straight dumped out the sides. A low RPM engine will generate a lot more back pressure through the same exhaust system because there is less volume being pushed through it at a lower velocity, that's why scavenging is important, to help evacuate as much exhaust gas as possible from the primary tube as possible before the next exhaust pulse hits the primary tube and runs into the previous pulse.

If our engines ran regularly at 6000+rpm then yes, I would agree that there is no need for additional scavenging, but since ours normally operate well below that level I still say you're very wrong that they don't need the scavenging benefits from a cross-over of some kind.

 

[db1]

dual plane same as cross plane?

 

[db1]

in fact flat plane cranks are what you find on most race cars like the ferrari f40 , tvr cerebra and some other cars like 10% of some bmw v8s. having said those types of motors have a equal firing order and equal exhaust pressure from both banks. almost like welding 2 4cylinder motors together. giving it a awesome sound. and no need for a x pipe or cross over.

dual plane has a un even firing order and uneven exhaust gas from both banks. so a cross over or x pipe would be beneficial for making more power.

could be wrong but thats how i understand it.