If you heard my truck at WOT, you would swear it had aftermarket exhaust. All the noise is the intake

I'm happy with my cheap ebay intake. It's pipe and a filter, not rocket science!

 

what is your definition of 'duel exhaust'?

split pipes ain't gettin' that rascal breathing.. not like a feed off of each bank into an x and ran dual would.. exhaust is one of my favorite subjects, please, for the love of God don't tickle me into typing.... i just might..

'true' true duels don't x or H.. they sound like two four bangers singing in concert.. you want an x or h as close as possible to convey pulses and promote scavenging.. ('crossed duels', 'x duel' some call it) you don't want ANY back pressure, and you want similarly spaced/lengthed runs of pipes..

i don't run a hemi, but several of my companies work trucks do.. i've marveled at how easy it would be to make them true duals.. I run a cali 5.9 on the right coast and don't suffer tedious inspections.. which made me running true duals pretty easy too (both banks are independently monitored upwind and down).. the hemi's in the work trucks have run dual to the cat, and single out.. that could be easily manipulated..

it sounds like you're talking about splitting pipes from the muffler.. that isn't going to gain you much, at all.. for a few dollars more, you can have true dual.. that WILL give you vroom.. and, it is making a wise decision, because all the stuff you will inevitably do to that engine will be bound up if you don't.. it's pretty simple- an engine is an air pump.. air in has to come out.. the 'in' isn't a bottleneck, yet, the out is..

'fix' the out first.. it will net you instant gains- not huge- but there.. more than a CAI.. from that point, it will already be addressed and anything north of the exhaust (everything) will see better gains than doing them by themselves.. good exhaust is about the best place to start modding 'smartly'..

 

06 Reg cab 4x4 all stock so far. 75000 miles

 

Drew, do you have any good links? I have a welding shop and am considering doing them myself. I would like an exhaust system with a deep sound. What would you recommend?

 

you're going to hafta talk to the hemi guys here to see what runs best on 'em..

displacement being similar, I'd imagine the pipe diameter would be similar as well.. you want that exhaust to remain hot as you can (which is why headers are coated in ceramic, or wrapped in exhaust tape, contrary to popular opinion- the insulation is to keep the pipes hot, an aside is also cooling off surrounding areas).. you don't want the pipes so restrictive in diameter that they choke and slow the pulses.. anywhere from 1 1/2" primaries to 1 3/4" should suffice.. but, we're talking headers here- those can come later... if you do what's south of them right you'll be reaping about 60% or so of the benefits of headers anyway..

after the headers, and iirc, there is either a Y pipe, or a duel in catalytic converter... the Y is silly restrictive, and at the very least should be replaced.. I suggest you ditch it all together and put an X pipe, or H pipe in there.. I'd run at least 2.5" pipes, but would lean toward 3" if it were mine.. you want to keep the exhaust pulses moving unimpeded, but not so much that it cools too fast and becomes a barrier for the pulse behind it..

a set of good high flow cats next.. OR, if your fortunate to find a duel in duel out high flow (I've seen them from Magna Flow, but haven't seen them in person) you can address both the x junction and the catalytic converter in the same move.. the cats are important in a full length exhaust system.. they warm the pulses back up once they've started slowing and becoming more dense (and a barrier for the pulse behind them).. keeping the flow moving is the name of the game.. you use heat to create vacuum (scavenging) that draws the pulses once the energy of the exhaust stroke has expired..

then you muffle it..

I'm with Hammer on this.. I despise chambered design mufflers.. they sound great, but they create back pressure.. not only that, they create back pressure right where the pulse is losing it's steam.. bad bad bad.. A good baffled or perforated design works best.. I chose a magna flow true x in stainless, 3" in 3" out.. I swear to you, I could have easily dropped a golf ball through that thing without hitting the sides.. but- it does a good job of- uh- muffling.. the chambered designs get that deep rumble easily- the perforated baffles get more of a woosh, and rely on the engine to produce it's own rumble.. I love the crap out of how mine sounds.. It's tame under idle, but when I push the go foot? that rascal GROWLS..

as far as mufflers are concerned, the humor i find with chokemasters is they compromise performance to give the illusion of being a performer.. whereas the unassuming perforated/baffled design rests easy, but open it up and it's comparable if not better sounding than the chambered.. flowmasters have become synonymous with 'posers'.. sorry, that's just the way it is..

anyway:

the biggest things to consider is pipe size, number of bends and angle/distance of bends, good flowing 'gotta haves' like cats and mufflers.. Hammer put together a nice list of flows on various mufflers in the FAQ section.. good stuff.. a high flowing cat is important, and NOT bypassing a cat is important.. the restriction it presents is almost offset by the heat/scavenging it generates..

later, you can come back and slap headers on.. if you choose the angle and run length of your collector-to-cat runs, you can leave margin for long tube, mid tube, or short tube headers...

you're doing the right thing by studying it up before you start.. too many people, myself included, start with popular but non complimentary mods, and end up spending extra time, money, and effort straightening that out in the end.. exhaust is the best place to start in my opinion..

 

I would definitely do exhaust first. theory being that you have to have room for the air to go before you suck it in. That's my Opinion

 

I'm gonna disagree with Drew here. I've done a bunch of exhausts, dual, true-dual, enhanced single and just about every pipe configuration you can think of. Also have done a little work at a performance shop in my younger days.

I personally don't like "true dual" meaning completely separate all the way from manifold (or headers) all the way to tip. I have always like to put an "H", "X" or "Y" in there somewhere for pressure equalization. True dual moves both the torque and HP curves up in the rpm band a bit (not a lot, but it still moves) when compared to the same system with just a simple "H" pipe welded in just before the mufflers.
I think there is a tad more low end grunt when pressures are equalized and (keep in mind this is personal preference) I think the sound is better when the pressures are equalized. I can always tell when I hear a true dual because I can hear the exhaust note change between sides as pressure increases on one and decreases on the other. Some may like that and that's fine, but to me it's always been kinda like nails on a chalkboard...

 

I miscommunicated or you read it cross-eyed..

I DON'T think TRUE true duals is a good thing.. you need that slight negative pressure created by the passing pulse.. that low pressure behind it drags the leading edge of the next pulse on the opposite bank.. that can only be done with H'n or X'n the banks at least somewhere before the pulses cool too much..

I run a magna flow true x muffler.. it X's the pipes after the catalytic converters (two magna flow high flow's).. it's not optimum, and at some point I'm going back in there, but it works more than a little better than the OE rig, and dropped that gawd awful Y pipe in the process, which is where my gains came from.. Mine is a cali rig, and has a total of four cats on it.. one pre-cat, each bank, just north of the collector, and then the high flow each bank.. and got rid of the floggin' HUGE single OE cat.. and then the true x muffler and dumped straight out the back..

we agree.. H or X it... what size piping for those Hemi's? 3" too much? is 2.25" too restrictive? the parameters with the 5.9L Magnum is somewhere between, and I don't have the headwork or cam to consider the 3".. yet.. I'm set pretty good at 2.5" (except it adapts to 3" right before the muffler- that's not by accident).. I'm figuring the Hemi displaces very similar volume, but I'm not familiar with the flow rate of that volume... it's more powerful than the Magnum, so that means more air is passing.. so, does that mean 2.5" to 3" is closer to optimum? I dunno the answer to that..

 

I probably read it wrong Drew. I'm on my phone and I have 44 year old eyes, LOL... I'm not gonna go back and re-read, just gonna post here:

I agree with Drew on this, you need to use some type of "X", "H" or "Y" pipe for pressure equalization...


OK? LOL...

 

sweet.... hehehehehee