I know very little about mechanics but want more hp for my duramax for pulling 5th wheel. Where do I start (i.e. exhaust size, intake system, etc.)
Thanks
2004 Duramax, 4" Tuff Country EZ-Ride Suspension Lift,
Toyo Open Country MT tires
2007 Cadillac Escalade, 20" Proxes S/T tires (Wifes)
2008 Cobalt 222 Boat


I see you have a 4" lift. Are you Running 33's or 35's. Depending on what gears you have currently you may want to think of some 4.10's-4.56's. A programmer would be your next best bet. Not only will it give you more power and better economy but you can program for the new gears and larger tires. There's always hearders and intake as well. I like gibson headers and k&n intakes but that's just me. Doesn't mean there isn't better out there but they are good for the price. I think maybe a nice 4" magnaflow set up would be great for you diesel.Hope this helps a little.
KRIS
2007 GMC Sierra CrewCab 4.8L
Tinted Windows, 20" Chrome MB Predators on 275/55/20 Copper AT's, GM Bed Rug, Speed Scene Chrome Grille, Putco Chrome Handles, Hypertech Max Energy Programmer, Magnaflow Muffler and many more mods to come.
Former GM Vehicles:
96 Chevy Camaro. My first car modded for a High School kid.
Do you have the 6.6 Turbo Diesel? If so you want to do things in order it is real easy to over elevate yor exhaust gas temp. I would put on an AFE Stage 2 xp intake on first then do an exhaust, Turbo back 4 or 5 inch MBRP makes a really good set also get the "cat test" pipe and muffler deleat pipes, after that I recomend you go to inovative diesel and check out their tuners. Once you remove some of the restictions you will notice a marked boost in power. I have a turbo diesel and this is the rout I am going. You could also upgrade your turbo and intercooler, but that gets real pricey!! Hope this helps!!![]()
Chris S. The GoFastPadre I like to drive fast and I've got the speeding tickets to prove it. 00 Sierra Z71 ECSB K&N CAI Pacesetter Shorties (soon to be replaced with LT's) Magnaflow HFC's Flowmasters with True Duals and H-Pipe more mods to come


Look at all the items GoFastPadre recomended and then add Propane and a Pyrometer to your list.
I have 2 trucks I use for hauling 39ft Goose neck trailers with loads in the 12k range (2001 Chevy 3500 Dually crew cab, and 2002 Dodge Dually extra cab) they both have propane kits, fill-ups are a little more expensive but with a load on the trailer they both avg. about 26mpg and burn clean. They also have more power. I looked at Banks Big Head and a few other Turbo mod kits but since 80% of the driving is out of state I wanted to keep the trucks close to stock for reliability and ease of finding a mechanic.
Tim
2011 Silverado 1500 LT
2008 HHR LT
1999 Tacoma SR5 TRD 4X4
1993 Jeep Wrangler
1991 Toyota Rock Crawler
2009 Harley Davidson Nightrain
2004 Harley Davidson FLHT "Bagger"
2003 Glastron GXL Bowrider




I own a Duramax and it sounds like you are looking at a few basic mods to give your diesel more HP for towing and achieve better mileage as well. I have a 6" lift and run 35's on my truck so a programmer is a must! I have the Quadzilla Stealth2 and it's one of the best out there for the price. I have 50, 70, 90, 110, and 135HP tunes to chose from and since yours is an 04, you will probably have the 210 tune as well. I was able to calibrate my speedo ( helps by changing shift points as well as calibrate your speedo according to tire size and gear ratio) and raise my speed limiter. You can also use the programmer to read and clear any DTC codes that may pop up as well as run diagnostics. I would recommend the 70HP tune for towing and the 90 works best for economy. I have also installed a 5" cat-back exhaust (still under warranty and the LBZ's are supposed to run better with back pressure from leaving the cat on) but you could go from the turbo back. As far as the AFE intakes, I had nothing but problems with mine due to the location of the MAF sensor mounting position so it threw codes constantly when I would get on it. The best intake to use would be your stock intake with a few simple mods to get it breathing better (unless your planning on achieving over 500HP then you will need an aftermarket intake). And the most important thing after these mods is an EGT guage of some kind to monitor exhaust gas temps while towing. The exhaust mod alone with help decrease your temps 200 degrees or so. Even with 35"s I am averaging 17MPG around town. If your not using a diesel fuel conditioner, it will help your diesel run better and achieve greater fuel mileage by adding lubrication properties back into your fuel that are now removed with the "ultra-low sulpher fuel"
Darcy
Washington State
2006 Silverado 2500HD LT3 4X4 CC SB Duramax LBZ
Tuff Country 6" lift, 35" Toyo M/T's on 20" Ultra Peacemaker wheels, Quadzilla Stealth2 programmer, Diamond Eye 5" cat-back exhaust, factory Special order color Yellow.



wow, nice darcy. couldnt have said it better myself
PETE
95 GMC Sierra 2500
3" Body Lift, 33" Goodyear MTR's
5.7L 350 TBI Edelbrock SDT Exhaust, Flowtech Headers, K&N Intake
Sold :(
1999 Jeep Cherokee, 3" Rustys lift, 33" BFG MT's, locked, armored: Rolled :(
2000 Jeep Grand Cherokee Limited. K&N Intake, Custom Kolak Exhaust
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Darcy, Great Post![]()
Chris S. The GoFastPadre I like to drive fast and I've got the speeding tickets to prove it. 00 Sierra Z71 ECSB K&N CAI Pacesetter Shorties (soon to be replaced with LT's) Magnaflow HFC's Flowmasters with True Duals and H-Pipe more mods to come
Just curious I just got out of my 06 dodge ehat size pipe does the dmax have factory?
It killed me how many guys bought facy exhaust systems for like 800 bucks when they could have spent 200 and done the same if not more? the dodge has 4" from the factory




The Dmax has 3-1/2" exhaust from the factory so 4" and 5" are the common upgrades.
Darcy
Washington State
2006 Silverado 2500HD LT3 4X4 CC SB Duramax LBZ
Tuff Country 6" lift, 35" Toyo M/T's on 20" Ultra Peacemaker wheels, Quadzilla Stealth2 programmer, Diamond Eye 5" cat-back exhaust, factory Special order color Yellow.
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