2014+ Exhaust Systems & Mufflers

SouthernSilveradoGuy85 · February 11, 2015

Mod the exhaust? What do you mean by that?

I've never had to mod the exhaust on any of my vehicles that I've put long tube headers on. Pretty much every kit on the market is a direct replacement for your exhaust manifolds, catalytic converters and Y pipe. Heck, on the trucks you could easily do the headers in afternoon if you have the tools available and a lift to help. Every kit I've used will bolt right up to your factory exhaust. All of the aftermarket companies I've dealt with offer full long tube kits for the trucks; stainless works, american racing, kooks, etc, etc.

You don't have to do any mods to the exhaust with long tubes but you do run into the problem with the check engine light coming on because the O2 sensors are programmed to see the exhaust gas at a certain temp and the long tubes have to move the O2 sensors down stream so the gasses are colder than expected but a tune shop can fix it pretty easily... Long tubes give a much greater gain on power and torque but shorty give gains over stock manifolds due to better scavenging. If price is a factor shorty headers are alot cheaper $500-$700 for shorty vs. ~$1600 for long tube

When I say mod the exhaust, I mean it's not a simple swap from the exhaust manifold. With long tubes you'll have to get rid of the downpipe and maybe even move the cat(s) back. Everything from the exhaust manifold or headers back to the tips is the exhaust right? Well the downpipe is part of the exhaust and cutting it out would be considered modding. Shortys you don't have to do anything at all to the downpipe or cats to get them to fit, they are direct replacements of the exhaust manifolds while long tubes aren't a direct replacement since you have to take out at least the downpipe and maybe move the cat(s) if the long tubes go further back than the downpipe.

DanMan_S · February 11, 2015

When I say mod the exhaust, I mean it's not a simple swap from the exhaust manifold. With long tubes you'll have to get rid of the downpipe and maybe even move the cat(s) back. Everything from the exhaust manifold or headers back to the tips is the exhaust right? Well the downpipe is part of the exhaust and cutting it out would be considered modding. Shortys you don't have to do anything at all to the downpipe or cats to get them to fit, they are direct replacements of the exhaust manifolds while long tubes aren't a direct replacement since you have to take out at least the downpipe and maybe move the cat(s) if the long tubes go further back than the downpipe.

The long tubes replace everything that is bolted up on the factory truck. If you look under the truck, the factory exhaust is bolted at the manifolds, and after the cats where it meets the cat back. The long tubes are a direct swap for everything up to the cat back flange and require NO MODIFICATIONS. It is definitely a simple exhaust modification as all of those parts are included with the long tubes. So a long tube kit will include the headers, the new down pipes, the new Y pipe and the catalytic converters (or straight pipe if you want to skip the cats). The cutting I do on my downpipes isn't a requirement for the headers, I just do it to speed up removal as I don't ever reuse the factory exhaust manifolds and trash all of the old parts. It's just for convenience but you definitely remove the factory manifolds, cats and y pipe simply by unbolting all of the flanges.

There is no playing around with the exhaust to get it to fit, you just remove all of the parts up to the cat back flange and bolt the new parts in. Below is a picture of the American Racing headers which is a pretty typical system for these trucks. That picture shows everything that they provide. The end connection is the spherical flange that mates up with your factory exhaust flange.

Edited February 11, 2015 by DanMan_S

SouthernSilveradoGuy85 · February 11, 2015

The long tubes replace everything that is bolted up on the factory truck. If you look under the truck, the factory exhaust is bolted at the manifolds, and after the cats where it meets the cat back. The long tubes are a direct swap for everything up to the cat back flange and require NO MODIFICATIONS. It is definitely a simple exhaust modification as all of those parts are included with the long tubes. So a long tube kit will include the headers, the new down pipes, the new Y pipe and the catalytic converters (or straight pipe if you want to skip the cats). The cutting I do on my downpipes isn't a requirement for the headers, I just do it to speed up removal as I don't ever reuse the factory exhaust manifolds and trash all of the old parts. It's just for convenience but you definitely remove the factory manifolds, cats and y pipe simply by unbolting all of the flanges.

There is no playing around with the exhaust to get it to fit, you just remove all of the parts up to the cat back flange and bolt the new parts in. Below is a picture of the American Racing headers which is a pretty typical system for these trucks. That picture shows everything that they provide. The end connection is the spherical flange that mates up with your factory exhaust flange.

Not all long tubes come with cats and some long tubes go further down than the pic you have. When I think of long tubes the first ones that come to mind are the actual long tubes that go all the way down and start going back. Plus replacing the cats would be considered modding since you're changing something int he exhaust behind the headers. Isn't putting in a catback exhaust modding the exhaust even though it's a direct hold in or am I wrong?

DanMan_S · February 11, 2015

Not all long tubes come with cats and some long tubes go further down than the pic you have. When I think of long tubes the first ones that come to mind are the actual long tubes that go all the way down and start going back. Plus replacing the cats would be considered modding since you're changing something int he exhaust behind the headers. Isn't putting in a catback exhaust modding the exhaust even though it's a direct hold in or am I wrong?

Most systems for these trucks that are readily available will be exactly like I posted. If a guy wants to get crazy and put headers with primaries that are longer than that, he can pretty much do whatever he wants and get a custom made set, but for most of us, we're buying commercial kits that are a direct bolt in swap for the factory system.

But along those lines, how is replacing the manifolds with shorty headers not considered modding? Modding is simply replacing factory parts with aftermarket pieces. Shorties, long tubes, or a full cat back are all modding the exhaust. It doesn't matter if it's a simple bolt in kit, or a full, custom mandrel bent and welded kit. A mod is a mod.

SouthernSilveradoGuy85 · February 11, 2015

Most systems for these trucks that are readily available will be exactly like I posted. If a guy wants to get crazy and put headers with primaries that are longer than that, he can pretty much do whatever he wants and get a custom made set, but for most of us, we're buying commercial kits that are a direct bolt in swap for the factory system.

But along those lines, how is replacing the manifolds with shorty headers not considered modding? Modding is simply replacing factory parts with aftermarket pieces. Shorties, long tubes, or a full cat back are all modding the exhaust. It doesn't matter if it's a simple bolt in kit, or a full, custom mandrel bent and welded kit. A mod is a mod.

I know it's modding which was my point when I said putting a catback exhaust in was also modding even though it's direct bolt in, I was being more specific to the exhaust OTHER THAN the headers themselves. That's why if I get headers for my '14 I will get shortys so that's all I'll have to deal with, not the downpipes or cats. I'm also not talking about headers for just these trucks even though I know this thread is about the K2s. I was talking about long tubes in general, not just specific to the K2 trucks.

DanMan_S · February 11, 2015

I know it's modding which was my point when I said putting a catback exhaust in was also modding even though it's direct bolt in, I was being more specific to the exhaust OTHER THAN the headers themselves. That's why if I get headers for my '14 I will get shortys so that's all I'll have to deal with, not the downpipes or cats. I'm also not talking about headers for just these trucks even though I know this thread is about the K2s. I was talking about long tubes in general, not just specific to the K2 trucks.

Even for other vehicles, the long tube header kits are the same. On my Z06's, my Mustang, my SRT8 jeep, my various GM and Dodge trucks, the bolt in kit with the long tubes, y pipe (x pipe in the case of cars with dual exhaust), cats/no cats are pretty much the same. With the except of custom jobs, say engine swap cars, old mopars, modern long tube kits are pretty straight forward bolt in jobs. On a few of my vehicles, I'd just run the headers with the factory catbacks, I know that my Mustang was already loud enough with the factory mufflers, headers, xpipe and no cats. In the case of my GM trucks, the factory exhaust really drones with headers, which is why I'd swap to the corsa catbacks.

Based on my experiences, going with the longtubes can be a easier install than shorties. Why? Because the exhaust manifold flange is tucked in so closely between the engine block and the frame rails that it's nearly impossible to undo the bolts, especially if the truck has some mileage and lots of heating/cooling cycles. That's why I end up cutting the down pipe instead, as it's faster to simply take the sawzall to the down pipes than try to get those bolts undone. Heck, I've broken those downpipes flange studs a few times, at which point the whole down-pipe has to come out no matter what to get the remains of the stud out. Dealing with the new downpipes and cats is easy as a lot of the header kits are really well done and easy to assemble. The fit and finish of the American Racing kits is always great, and you can loose fit the downpipes to the headers and the catback, nicely tighten the headers to the engine, then go back and quickly tighten up the rest of the flange connections under the vehicle.

Edited February 11, 2015 by DanMan_S

hotrodz37 · February 12, 2015

Had the Borla Touring (muffler) only installed. Sounds the same as stock so I will probably remove the resonator next. Since it is center in center out and the stock muffler is offset in center out a new piece of tubing had to be welded in. Question for you guys - I have only had pre-fabbed systems on my other trucks so the tubing was mandrel bent. Wanted to get the consensus on how you thought this pipe looked and if it was a quality job. Welds are decent, not perfect, but just wanted to get your take on the bends and if I am losing any performance here. Since the borla is straight through im sure it has less restriction but the bends have me questioning it some - seems like it is a little down on power (could be just in my head).

Edited February 12, 2015 by hotrodz37

Luster · February 12, 2015

Had the Borla Touring (muffler) only installed. Sounds the same as stock so I will probably remove the resonator next. Since it is center in center out and the stock muffler is offset in center out a new piece of tubing had to be welded in. Question for you guys - I have only had pre-fabbed systems on my other trucks so the tubing was mandrel bent. Wanted to get the consensus on how you thought this pipe looked and if it was a quality job. Welds are decent, not perfect, but just wanted to get your take on the bends and if I am losing any performance here. Since the borla is straight through im sure it has less restriction but the bends have me questioning it some - seems like it is a little down on power (could be just in my head).

That's pretty typical of shop-bent pipe. I doubt if you're down on power. Just too quiet, like my 22" Magnaflow was. When I went to the 14" Magnaflow, I "perceived" it to have more power, just because of the sound. But, again, I'm not convinced there was any gain.

If you want HP gain, put some E85 in it! Wow!

SouthernSilveradoGuy85 · February 12, 2015

Had the Borla Touring (muffler) only installed. Sounds the same as stock so I will probably remove the resonator next. Since it is center in center out and the stock muffler is offset in center out a new piece of tubing had to be welded in. Question for you guys - I have only had pre-fabbed systems on my other trucks so the tubing was mandrel bent. Wanted to get the consensus on how you thought this pipe looked and if it was a quality job. Welds are decent, not perfect, but just wanted to get your take on the bends and if I am losing any performance here. Since the borla is straight through im sure it has less restriction but the bends have me questioning it some - seems like it is a little down on power (could be just in my head).

I personally don't care for pre-made pre-fab exhaust kits because they're usually more. The pipes are usually mandrel bent which makes it cost more which to me is more for looks than anything. Also I'm picky so if I want a certain setup it will be hard to find a pre-made setup exhaust how I want. I mean with a certain muffler, tailpipe and how the tips are positioned. I'd rather just go to a good shop and tell them how I want it.

Anyways, I doubt you'll feel any difference if there is any performance lost. I mean the air won't be as free flowing at the bends, but it's nothing you should be able to notice. The only time I would want mandrel bent pipes would be on muscle cars (classic or modern) or any show vehicle which I'm not into all out show vehicles.

Jon A · February 12, 2015

I'm really debating whether or not I should invest in some American Racing Headers for the truck. I feel that they would free up a considerable amount of power along side a tune, BUT, am worried they will be too loud to daily drive. I know a few members have ARH on here and would like some input as to how they are on a day to day basis.

It's all about the catback. The headers added very little volume to mine--they changed the tone noticeably, but it's not really much louder. I know my truck with the headers and the Magnaflow 22" catback is quieter than plenty of trucks with no headers but louder catbacks. Just fine for a daily driver.

07Softail · February 13, 2015

UGGH! Those crimps in the pipe make me cringe!!!! It screams ZERO PERFORMANCE!! Will you feel any difference in the seat....No but it's disrupting flow no doubt. I will take the Mandrel bent pipes any day even if I had a Honda Civic!! LMAO

RT

taps929 · February 15, 2015

Hey all, got a '14 silvy (5.3) and looking to add a cat back system. I guess what im looking for is a nice deep tone that will stay constant through the rpms. I put the flowmaster american thunder set on my 04' titan (had it welded instead of the clamp set up)and sounded great on start up and lower rpms, but at higher rpms and under heavy petal it made a clapping type noise that i hated. Made it sound cheap imo. Is there a brand type known exclusively for deep deep tones? Or a certain length of the muffler change this? I guess what im looking for is more a deep chested Great Danes growl versus the angry Pitbulls bark if you get my jist. Thanks for any input.

SouthernSilveradoGuy85 · February 15, 2015

Hey all, got a '14 silvy (5.3) and looking to add a cat back system. I guess what im looking for is a nice deep tone that will stay constant through the rpms. I put the flowmaster american thunder set on my 04' titan (had it welded instead of the clamp set up)and sounded great on start up and lower rpms, but at higher rpms and under heavy petal it made a clapping type noise that i hated. Made it sound cheap imo. Is there a brand type known exclusively for deep deep tones? Or a certain length of the muffler change this? I guess what im looking for is more a deep chested Great Danes growl versus the angry Pitbulls bark if you get my jist. Thanks for any input.

My Flowmaster Super 44 single in/dual out sounds awesome. Just has the V4 drone which doesn't bother me, kind of like it since it sounds like a big rigs exhaust brake lol. If you want it really loud then this might not be the muffler you want. I park it on the street and if I start it from the back of my house or back yard I can hear it just fine. I don't know how loud it is from the outside of it driving but being that the cab is a "quiet cab" I'm sure it's loud. Best sounding exhaust I've ever had on a truck.

https://www.youtube.com/watch?v=mQxoOtyr1qs

Edited February 15, 2015 by SouthernSilveradoGuy85

taps929 · February 15, 2015

@Ssguy85. Thanks. That does sound pretty good. Im looking for quality>quantity, so loudness isn't priority. Ill look into that one more. Was looking at the Borla S type but man are they pricey. Pypes has a Violator muff that sounds decent also, but its really hard to tell through a video. As for drone yeah, getting used to that. Im on my 3rd oem muffler due to the little flapper failing. Get the high pitched whistle when it comes out of v4, and when in v4 around 40 mph it gets pretty bad. Like a large subwoofer on a bad note. But again, thanks