Basics on Increasing Horsepower

[Chubbs]

So my apologies if this has been asked before. Bear with me. I'm still new to underhood mods and changing things performance wise. As of right now, I have a spectre CAI, that I got from another member and love it, on my 2006 Denali XL with the LQ4 6.0. Everything else is stock setup. Now, I think a cat is starting to go bad(I think there's 2 right?!) so here's my question, when I have the cats(?) replaced, I want to do a custom exhaust while everything is opened up down there. What's a simple exhaust mod route to go, that will give my truck a nice beefy sound, but not too crazy, maybe a little more kick when I go, but not necessarily have to have this, And what would I need to replace my cats and not break the bank? I also don't really understand the differences in exhaust setups, so any insights you guys have to share on that would also be appreciated!

Air filters and exhaust systems will not provide any neck-snapping horsepower LOL. I think you are getting a placebo affect from the cash that you are spending. A high dollar exhaust will only make your truck sound different. If you need new catalytic converters then a cat-back exhaust system isn't a bad idea but don't spend a lot of money on that unless you plan to at least have the PCM tuned. A high dollar exhaust will add nothing performance-wise. High flow headers and cat' converters are needed for folks with actual engine mods (stroker/big bore/forced induction/camshaft) and allows that new high volume of intake to be expelled by the engine at the same rate. If you spend $800 for a new sound more power to you but if you are conservative please keep in mind that you only need a high flow exhaust if your intention is to build on your motor.

These trucks are getting old. Soon as you spend 1/2G$$ on something unnecessary, it will need a very necessary 1/2g$ repair so I always have that in mind. Better off putting a cheap cat' on it and have the cash handy when a wheel bearing or Ujoints start to fail.

 

[adventurenali92]

Air filters and exhaust systems will not provide any neck-snapping horsepower LOL. I think you are getting a placebo affect from the cash that you are spending. A high dollar exhaust will only make your truck sound different. If you need new catalytic converters then a cat-back exhaust system isn't a bad idea but don't spend a lot of money on that unless you plan to at least have the PCM tuned. A high dollar exhaust will add nothing performance-wise. High flow headers and cat' converters are needed for folks with actual engine mods (stroker/big bore/forced induction/camshaft) and allows that new high volume of intake to be expelled by the engine at the same rate. If you spend $800 for a new sound more power to you but if you are conservative please keep in mind that you only need a high flow exhaust if your intention is to build on your motor.

These trucks are getting old. Soon as you spend 1/2G$$ on something unnecessary, it will need a very necessary 1/2g$ repair so I always have that in mind. Better off putting a cheap cat' on it and have the cash handy when a wheel bearing or Ujoints start to fail.

So like I said, I'm not looking to go big on power. I also didn't say I was going to spend a ton of money on useless product. I was asking for simple advice. Your reply wasn't very helpful.

 

[Rocket Man]

So my apologies if this has been asked before. Bear with me. I'm still new to underhood mods and changing things performance wise. As of right now, I have a spectre CAI, that I got from another member and love it, on my 2006 Denali XL with the LQ4 6.0. Everything else is stock setup. Now, I think a cat is starting to go bad(I think there's 2 right?!) so here's my question, when I have the cats(?) replaced, I want to do a custom exhaust while everything is opened up down there. What's a simple exhaust mod route to go, that will give my truck a nice beefy sound, but not too crazy, maybe a little more kick when I go, but not necessarily have to have this, And what would I need to replace my cats and not break the bank? I also don't really understand the differences in exhaust setups, so any insights you guys have to share on that would also be appreciated!

Denalis have a pretty decent factory exhaust. Instead of a y-pipe and a single exhaust from there back they have a dual exhaust all the way back to the muffler and the diameter is bigger ( dual 3 " I believe) than Tahoes or standard Yukon's. Best bang for the buck when replacing cats on a Denali is high-flow cats( if possible in CA )and then replace the muffler with something with more flow. If I remember right you'll have a dual in, single out muffler which limits your choices there. I had a merge pipe added to my Denali in front of the muffler so I could go to a single in, single out which opened up my choices. There's nothing really to gain with a cat-back on a Denali except for looks in my opinion. (You do have 2 cats right after the exhaust manifolds but no y- pipe, just dual pipes all the way to the muffler.)

 

[Chubbs]

So like I said, I'm not looking to go big on power. I also didn't say I was going to spend a ton of money on useless product. I was asking for simple advice. Your reply wasn't very helpful.

Sorry dude. I got confused by what you were actually wanting to know.

You are wanting suggestions as to how and what you should replace your factory exhaust with, mostly for a better sound, and how/what you should do with the cat'converter should it need replacing? Right?

I'm of the opinion to replace the cat' converter with an aftermarket or OEM of the same type original to the truck. Then you can change the muffler to something of your preference. There are so many different mufflers & so many opinions that it's like asking the regulars @ applebees which beer you should drink. 1 guy may think his Flowmaster50 is the best thing ever while the next guy who bought that had it removed the very next day & changed to a Magnaflow on H-pipe. Borla mufflers with X-pipe has its following. X-pipe & Flowmaster44. These are 2 mufflers instead of I think the 1-muffler system that your truck comes with. I don't know about the 6.0 Denali but there 100-options. My best advice is to not allow the shop tech to make your choice for you or suggest what his preference is; that never works out well. Go in there knowing exactly what you want or with what you have ordered for install only.

You can YouTube "Denali+muffler+flowmaster+borla+6.0" any & all combinations & listen to sound clips of the different setups. You can hit Amazon & Google for catbacks and search until you find a deal that's good for you but performance-wise the cost doesn't justify the means and most setups are designed with either performance/sound/appearance in mind, therefore priced super-high according to that niche market people are shopping in.

You will get more responses & hopefully some sound clips of member exhaust for your options bank but def search around for sound clips. If you have emissions testing where you live, even better to keep the cat' close to stock so there aren't issues with oxygen sensors & check engine lights. The muffler only can be swapped to get a different sound but anything like performance exhuaust and upgrading to larger I.D. Piping would not add a whole lot more to sound or power than a different muffler would, alone. Doing 2 mufflers on a crossover pipe increases the sound for sure but doubles the budget. Economically, a high-flow, high performance system won't do as much for your truck in relation to the cost. You can change the tone and replace the cat' for a decent price & leave it at that. Just know that even a cheap, knockoff cat' converter runs $150, closer to $250 for a single OEM replacement, which is pricey to me and not so much the next guy. A cat-back costs way, way more but doesn't help you as you probably need the cats' anyway, or at least 1. On the other hand, if you find both your converters to be functioning properly a cat-back Magnaflow with the chrome stumpy tips exiting behind the back tires will look amazing on your truck and sound like a dream. Then the $1000 or whatever it is may be worth it to you.



Something like that...

Sorry for coming off like a d!ck earlier.

 

[Rocket Man]

Sorry dude. I got confused by what you were actually wanting to know.

You are wanting suggestions as to how and what you should replace your factory exhaust with, mostly for a better sound, and how/what you should do with the cat'converter should it need replacing? Right?

I'm of the opinion to replace the cat' converter with an aftermarket or OEM of the same type original to the truck. Then you can change the muffler to something of your preference. There are so many different mufflers & so many opinions that it's like asking the regulars @ applebees which beer you should drink. 1 guy may think his Flowmaster50 is the best thing ever while the next guy who bought that had it removed the very next day & changed to a Magnaflow on H-pipe. Borla mufflers with X-pipe has its following. X-pipe & Flowmaster44. These are 2 mufflers instead of I think the 1-muffler system that your truck comes with. I don't know about the 6.0 Denali but there 100-options. My best advice is to not allow the shop tech to make your choice for you or suggest what his preference is; that never works out well. Go in there knowing exactly what you want or with what you have ordered for install only.

You can YouTube "Denali+muffler+flowmaster+borla+6.0" any & all combinations & listen to sound clips of the different setups. You can hit Amazon & Google for catbacks and search until you find a deal that's good for you but performance-wise the cost doesn't justify the means and most setups are designed with either performance/sound/appearance in mind, therefore priced super-high according to that niche market people are shopping in.

You will get more responses & hopefully some sound clips of member exhaust for your options bank but def search around for sound clips. If you have emissions testing where you live, even better to keep the cat' close to stock so there aren't issues with oxygen sensors & check engine lights. The muffler only can be swapped to get a different sound but anything like performance exhuaust and upgrading to larger I.D. Piping would not add a whole lot more to sound or power than a different muffler would, alone. Doing 2 mufflers on a crossover pipe increases the sound for sure but doubles the budget. Economically, a high-flow, high performance system won't do as much for your truck in relation to the cost. You can change the tone and replace the cat' for a decent price & leave it at that. Just know that even a cheap, knockoff cat' converter runs $150, closer to $250 for a single OEM replacement, which is pricey to me and not so much the next guy. A cat-back costs way, way more but doesn't help you as you probably need the cats' anyway, or at least 1. On the other hand, if you find both your converters to be functioning properly a cat-back Magnaflow with the chrome stumpy tips exiting behind the back tires will look amazing on your truck and sound like a dream. Then the $1000 or whatever it is may be worth it to you.

View attachment 179716

Something like that...

Sorry for coming off like a d!ck earlier.

Denali's are different than the Tahoes and Yukons, it has dual exhaust all the way to the muffler. Your picture there does him no good, and if a spare tire is important then the dual exhaust from the muffler back won't work anyway. I've seen it done on our rigs but it takes a lot of custom work. I've included a couple pics of mine for reference on a Denali. My headers (first picture) are exact copies of what the Denali's have, dual all the way to the muffler and no Y-pipe. The second picture shows where they connect to the stock muffler. There's 2 pipes coming forward from the stock muffler that bolt up to the 2 coming back from the engine. Those pipes are welded to a dual-in, single-out muffler. It's actually a pretty free-flowing system and just needs a bit of upgrading as far as a new muffler goes and high-flow cats if they're approved for your local emissions. A cat-back on a Denali isn't worth much in my opinion.

 

[Chubbs]

Hey red! Thanks for following up and providing the specific info on his model. You're good!

I live out here in Dallas where the county has somewhat strict emission regs so yes, it is important to be clear on that subject and understand that aftermarket exhaust not to OE-spec could have negative effects.