What To Do To 2004 Denali?

mhorn0817 · September 1, 2007

Welp i just picked up a 04 denali last night, extremly clean inside and out,34k miles, sunroof,dvd sytem, etc etc...love the truck, now im ready to start havin some fun... Now i was always told the more free flowing air IN and OUT will give you more power AND if you dont drive like a nut give you better gas mileage...just wondering what things i should do to get both horsepower and better mpg. id figure atleast a cold air intake and would like to know which one is best bang for the buck for the denalies...any other info or tips or tricks would be greatly appreachiated! thanks in advance!

omegafiler · September 1, 2007

Check out the sig for mods/pics. I'd go with custom tune first. Then look into exhaust/intake. That right there should get ya going.

mhorn0817 · September 1, 2007

oh ok...well what are some good tuning componay for our trucks? and of course the best bang for the buck....plus with exhaust i want something free flowing but i dont want it loud...is that out there? lol

omegafiler · September 1, 2007

Well, if you get exactly what I have in my sig, I think you'll be 100% happy. You know, save you from having to do all the research I did. And I'm very picky!

But here's why!

Tune:

I checked around quite a bit and there are quite a few custom tunes to go with. And Wait4me was indeed the best bang for your buck. Lots of very happy users. But, unlike all the others, they offered their custom tune on a handheld (SCT). This allows me to select from 3 different custom tunes (Max Tune, Performance, Mileage), and go back to stock when it has to make scheduled visits to the dealer. So I've got the custom tune, it runs awesome.

Exhaust:

I originally went with a Magnaflow muffler, the longest and quietest one I could find. But it had way too much Drone once you got the RPM's at or above 2k. Not to mention when you were carrying a load of people and/or cargo. This 6.0l is considerably louder with aftermarket exhaust systems than a 5.7 or 5.3 V8. I added a 2nd muffler... but then it just sounded too quiet and wasn't at all what I wanted from an exhaust. I got my Corsa Sport installed and I absolutely love it. It is rather loud on acceleration and makes your truck sound like a race car - but no drone! However, if you do tow, even the anti-drone Corsa may be a bit too loud. In which case you can opt for their quieter and slightly more expensive Touring system. So if ya want it quieter, this may be the way to go for you.

Intake:

There are lots of intakes and they'll all work about the same as long as they are enclosed and don't pull in heat from the engine bay. Some of the cheaper ones are just a tube and cone that hang in the engine bay. Wouldn't recommend this. I went with the GMPP for a few reasons. First, it looked awesome - very shiny (see pics). Second, it could be installed by the dealer and remain 100% warranty friendly. The intake ads a bit of a growl to your engine and provides better throttle response across the entire RPM range. Mods like air intake really shine with other supporting mods, such as the tune/exhaust.

Of course there are other options out there, but it's what I've got, and I couldn't be happier with this setup. These 3 performance mods alone have been plenty to really wake up my truck and give it the power it should have had from the factory. At least enough to keep me happy for quite awhile!

BigJayDogg3 · September 1, 2007

Omega, did you lose much power when you went to the dual mufflers?

omegafiler · September 1, 2007

Omega, did you lose much power when you went to the dual mufflers?

Nope, no change at all in power with the 2nd muffler. It was also a magnaflow (much smaller), so it was straight through, no restriction. It's just like "turning down the volume" on your exhaust.

mhorn0817 · September 1, 2007

hmmmmmmmmmm all that sounds like some great info...how much HP and TRQ and MPH do you think you gained? would you happen to have website links and prices? did you have to send anything away for the programing?

SS Crew · September 1, 2007

Get a tune for performance, this will give you your best bang for the buck. And put on a Corsa exhaust system, it's never annoying and sounds great when you get on it! And your done!

omegafiler · September 2, 2007

hmmmmmmmmmm all that sounds like some great info...how much HP and TRQ and MPH do you think you gained? would you happen to have website links and prices? did you have to send anything away for the programing?

Sorta depends on your particular engine, the type of tune ya go with (ie. Performance, Mileage, Max Tune, etc), and what other combination of mods you have. On average, with a tune only, about 20-30hp for most folks. You'll normally get quite a bit more with the 6.0 as they're rather "de-tuned" from the factory. Of course once ya get a tune, you won't care.

Wait4Me Custom Tune w/ SCT Handheld - About $369 shipped. If you just go with the PCM swap, where he sends you another PCM (so you don't have to send anything), its about $160. I just prefer the handheld. Either way, you never need to send anything to them - except payment.

GMPP Intake - You can get it from the dealer, or buy it on-line, GMpartsdirect.com, for example. Part# 17801346. Retails for $400.

Corsa Exhaust - The full cat-back system retails for well over $800. There are a few retailers who sell 'em. I'd check out ebay - got mine for $600, new.

mhorn0817 · September 3, 2007

wow thanks for all the info, now for the tuner do i get the tuner with the 3 tunes for 369 or do i have to have a tuner? and also i did some searching and found a S&B intake with the closed with for 210 bucks, think that would wokr ok? ill have to find the site again....and for the exhaust did you get in from a wholesale dealer on ebay or a person? thanks again for alll the help!!!

omegafiler · September 3, 2007

wow thanks for all the info, now for the tuner do i get the tuner with the 3 tunes for 369 or do i have to have a tuner? and also i did some searching and found a S&B intake with the closed with for 210 bucks, think that would wokr ok? ill have to find the site again....and for the exhaust did you get in from a wholesale dealer on ebay or a person? thanks again for alll the help!!!

No problem! The $369 includes the SCT handheld tuner (like a Hypertech or Flashpaq handheld), except is has 3 custom tunes loaded on it for you, so you won't need anything else. I haven't used the S&B intake, but it looks like a nice CAI from the pics I've seen around here. As for the Corsa, I'm not quite sure. Just found somebody on eBay with good feedback and was offering it as "new."

Good luck!

mhorn0817 · September 4, 2007

great that all sounds good then....now the 3 different tunes on the sct....can i just switch back and forth between them or do i have to reflash everytime i wanna switch back and forth?

and do you know anything abot the exhuast system that gmpartsdirect offers?

SLPR_04 · September 4, 2007

and do you know anything abot the exhuast system that gmpartsdirect offers?

The GMPP Exhaust is now made by Borla. But it used to be made by Corsa. If you look around hard enough, you can find the Corsa systems for around $600. I got lucky with mine and found a GM dealership on Ebay. They were getting rid of all their old Corsa stock making room for the new Borla systems. I got mine for $460 and that was with free shipping. So the deals are out there just gotta dig for them. ;)

As far as the custom tune goes. I believe that you have to get it flashed to change between the different tunes, I think?

Just hit the forum search function, and search for custom tunes, or exhaust, or maybe cai or intakes. There is so much info on these boards it is crazy. Have fun with all the mods for your new ride.

mhorn0817 · September 4, 2007

thanks for the help....im ive found alot of exhausts on ebay for decent prices...gmpp , borla,corsa,magnaflow,flowmaster,gibson,cgs (know anything about them?)....what i want is a nice free flowing exhaust, that'll give me more power and mpg (when im not on it) and sound close to stock. dont want anything to loud and also get the best bang for my buck

same for the cold air kits, see the k&n , volant, s&b, gmpp...jsut want peoples opinions on them if they have them....because if the s&b works jsut as well as all the others im gonna go with them since theyre cheaper.

thanks for all the help!

omegafiler · September 4, 2007

thanks for the help....im ive found alot of exhausts on ebay for decent prices...gmpp , borla,corsa,magnaflow,flowmaster,gibson,cgs (know anything about them?)....what i want is a nice free flowing exhaust, that'll give me more power and mpg (when im not on it) and sound close to stock. dont want anything to loud and also get the best bang for my buck

same for the cold air kits, see the k&n , volant, s&b, gmpp...jsut want peoples opinions on them if they have them....because if the s&b works jsut as well as all the others im gonna go with them since theyre cheaper.

thanks for all the help!

With the SCT, once programmed, you can easily switch between the 3 custom tunes (only takes about 20-30 sec). Just about any CAI will work, everybody is pretty much happy with whatever they happen to have. For exhaust opinions, just gotta search around. There are tons of posts including exhaust clips. But I think you'll find that most exhaust opinions are also going to vary a lot and you'll ultimately need to pick one that sounds good to you.

Also, when seaching the forum for exhaust stuff, just make sure you note whether they have the 6.0 or not... huge difference with regards to drone when compared to the 5.3/5.7.