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Discussion Starter · #1 ·
But here goes...

To preface, the Hemi is the first V8 I've owned in 20 years. All my cars previous to that were 60's/70s muscle cars.

I'm reading about catback dual exhaust blah blah blah...

My question is, WHY aren't we running headers with true dual exhausts? Is it a catalytic converter issue or is it more the kids are into the single exhaust thing today?

Pardon my ignorance here, but in my era, you want these types of motors to breathe with dual 2-1/2" or 3" exhausts - the shorter the exit pipes (like side pipes), the better...

Thanks in advance for the inservice!
 

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undefined It is just a matter of personal preference. I am having my 1500 hemi converted to true duals next tuesday. Yes, it is performance enhancing. If it is well designed, with few bends, and quality mufflers, it will help performance. Single exhaust is installed at the factory for one reason, it is cheaper. Any factory design can be improved upon. Anyway, this is just my opinion, as I am a fan of true duals, not the fake single in dual out designs. Good luck. :gr_patrio
 

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The major issue at hand is emissions control.

Most places like here in CA you cant legally even think about touching the cat.
 

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Tank Mech
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I think the major factor is indeed emissions. Places like Cal. will fail you if your system doesn't pass the visual inspection, meaning you can fail for modifying it, whether it is more efficient or not.
But I also don't think engines these days are as reliant on scavenging as the older ones were. For example, throttle bodies. When I was wanting to open my TB up a little, I was concerned about taking out too much material arouind the venturi. But after it was all over and done with (not quite yet, I'm gonna take it back off, and open it up some more) I realized that today's gas engines don't need the effects of the venturi anymore. Remember? A carburetor motor needed the venturi, to increase air velocity and decreasing the air pressure, to suck fuel out of the different fuel supply circuits.
Well, MPFI motors rely on the computer and the injectors for fuel supply, regardless of the air's pressure or velocity. The same goes for the exhaust side. The benefits of exhaust scavenging aren't quite as eye-opening as they were twenty years ago. The scavenging effect didn't just stop with clearing out the cylinder for the new intake charge, it also continued on through to the carburetor, allowing a further increase in intake velocity (added up, more fuel, more power).
True duals today will surely make more power. Not the jaw-dropping increase that you would have gotten from a '68 327 Camaro, but an increase nonetheless. It just has to be decided whether the increase will be worth the dollars spent.
 

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Discussion Starter · #8 ·
327 Camaros *heh heh*

I used to piss all over those all day long with my stock '66 C-body Chrysler 300. They'd get me out of the hole by half a car length because I was smoking tires, but after a second or two I was waving "buh-bye!".

As for the computer controlled engines of today, I posed the question in another thread a while back: if all the computer crap was stripped off the motor so it could function like a crate engine, how much HP could be unleashed?
 

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Tank Mech
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I remember that thread. The problem with trying that is the fuel ramping. Without the 'puter, there's no way to control fuel into the engine. But if someone were to fab up an intake and install a carb, I don't see why it wouldn't work. But then if you keep the tranny, you gotta figger out a way to make it shift right (once again, without the 'puter).
But me? I'm just going to let the 'puter do it's job while I make it easier and easier for it to do just that, lol:D
 

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Yea everything is computer controlled now , the biggest thing is the fuel, you can bring in more air but the computer may not bring in more fuel, even the exhaust is tuned to create the right mount of low end torque, unfortunatley for the Hemi from what ive read the programmers arent helping much either to reprogram the system to maximize HP gains, until then we can only dream of the days of changing intakes and carbs , opening up the exhaust and reeping the benefits of the old fashioned Muscle power..
 

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I sent my Superchips Programmer back since I noticed very little gain in my 2003 4.7 4x4. There was some crispness in response, but not worth the $580. (Canadian) price tag and the commitment to 91octane fuel at the current rate. Damm computers!
 

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34504 said:
undefined It is just a matter of personal preference. I am having my 1500 hemi converted to true duals next tuesday. Yes, it is performance enhancing. If it is well designed, with few bends, and quality mufflers, it will help performance. Single exhaust is installed at the factory for one reason, it is cheaper. Any factory design can be improved upon. Anyway, this is just my opinion, as I am a fan of true duals, not the fake single in dual out designs. Good luck. :gr_patrio

Good luck. But after reading hundreds of posts on this subject I went SI/SO. I am a huge fan of true duals also, but I dont think the Hemi agrees with them. I found a low end power boost from my muffler swap. Where most people that go SI/DO feel a low end loss. I went with what works. An it did. :D
 

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agreed Blackwolf
 

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I look at it this way, to the best of my knowledge, there isn't a 4 stroke engine that will not respond in a positive manner to a reduction in backpressure. Sure, you may loose some lower end, but the loss is not that great, and the sound alone is pure heaven!! You cannot put a price tag on that, can you? I guess that everyone in this group can go back and forth on the pros and cons of true duals, but it boils down to money and preference. And my dual system is after cat, so emissions are not affected. Like I care, but oh well, it is the law, right? NH is just starting emissions testing this year. Who Hoo!!! See ya all!! Dodge forever!!!!!!
 

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34504 said:
I look at it this way, to the best of my knowledge, there isn't a 4 stroke engine that will not respond in a positive manner to a reduction in backpressure. Sure, you may loose some lower end, but the loss is not that great, and the sound alone is pure heaven!! You cannot put a price tag on that, can you? I guess that everyone in this group can go back and forth on the pros and cons of true duals, but it boils down to money and preference. And my dual system is after cat, so emissions are not affected. Like I care, but oh well, it is the law, right? NH is just starting emissions testing this year. Who Hoo!!! See ya all!! Dodge forever!!!!!!

Well the money and preference thing is 100% wrong. I have the cash to put any exhaust I want, which is what I did. And I prefer true duals, yet choose what I thought would be best for the truck. I think I decreased back pressure since I went with an open Aeroturbine 3030 and no resonator. And as for sound, I'll challenge a true dual anyday. ;)

I run long tube headers to an open cutout in my TA. So I'm no stanger to loud exhaust.
 

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Like I said, it is all opinion and perception. That is the beauty of this hobby, so many ideas, and opinions. Your rigs are both beauties, too. I am sure you enjoy them both.
 

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Fair enough. And thank you. ;)
 

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the75powerwagon said:
i have true dual exhaust.. but i dont have to worry about smog! thank god.
Because of the age of the truck? I don't have smog issues either. No inspections in Florida. :D
 
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