SsZERO

It's somewhat of an amusing story...I went to the GM Autoshow In Motion last thursday, drove a bunch of cars and trucks including the GTO, Z06, Hummer H2 and others...but got instantly hooked on the diesel GMC Sierra SLT.

Shortly thereafter, I went to GMC's website and Chevy to check some pricing out, did my research and went to a dealer and bought a 2500HD Silverado LT 4x4 ext. cab with the short box and 5-speed allison tranny.

I absolutely love this truck, and no less than 5 days ago, I was strictly a car guy who maintained that people shouldn't drive trucks around unless they need their towing/hauling/utility capabilities. Narrowminded, but practical. Yeah, I'll admit, the truck can be a bit tricky to pilot in the city, but that is something I am more than willing to live with.

Anyway, I have never owned a pickup truck before, nevermind a diesel. Do you diesel guys got any tips for a new owner? Maintenance, performance, ride quality. I orded a DualComp bedliner, because I do not want to apply a spray type. The DualComp seemed like a decent compromise. Anyone here have that?

What do these things dyno? They claim 520 lbs of torque and 300 HP...what is that at the wheels? Do those chips that claim to add extra HP and TQ really add as much as they claim?

Hit Man X

I've driven two Dmax trucks an '03 LB7 and an '04 LLY...the newer motor kicks ***! The entire truck just drove better. I'm still planning to order one this fall (so long as the GMC front end looks the same) as I want a sunroof!

I'm not familiar with that bed liner, I'm a fan of a quality spray in from Line X or Rhino. From what I've read the stock shocks suck on those trucks. So I'd highly consider getting a new set fairly soon. Shell Rotella oil is pretty good apparently. Clean fuel is important to power and economy...I'd change fuel filters fairly often like 10K mi tops.

300/520 is the net HP figure, I think the HP is around 220-240rwhp and like 420rwtq. Those chips/boxes/reflashes add insane power gains. The mild ones like 50-70hp gain most in 1st gear as the truck defuels a lot (prolly for EPA/CAFE reasons) so you gain a lot right off the bat with a small box.

Over 100hp/200tq you will slip the stock torque converter in 5th gear under full power. Suncoast and ATS make kickass replacements, billet steel covers, multiclutches, etc. After you get that to stop slipping, you will begin to burn the C2 and C3 clutch packs (there are 5 total, ergo you have 5 fwd gears with 3 planets meaning that unit could be a 6 speed! ).

TransGo has a nice shift kit out for the Allison and ATS has a badass setup called the CoPilot out. If you're going to pull the tranny, I'd do it only once if you can. A converter and Valve Body build will hold a good amount of power and make you smile.

Edge Products makes a great unit that goes in the CAN-Bus under hood. Bully Dog does too. Quadzilla has an underhood unit and a PCM reflash box. TTS flashes the PCM too. Oh also, these are stackable meaning you can run more than one at the same time. The Edge Hot Juice and the Quad Stealth 215 seem to be the combo for BIG power.

SsZERO

Wow, are you serious? I knew this truck was sweet, but I had no idea I could actually make it quick. If I stack a Hot Juice and Quad 215, what do I end up with? What does the co-pilot thing do? And what does a valve body build involve?

10.5 Dave

iTrader: (5)

See sig for dyno #'s with a programmer,exhaust and air filter.I agree with everything Hitman X is saying except the fuel filter replacement interval.I buy all my fuel at truck stops that sell a bunch of diesel.I feel that is more important than excessive filter changes.When I got my truck I listened to people telling me to change the fuel filter every 10 k and after cutting the filters open it became obvious there was no need to change them that often.My schedule is for oil change and lube at 10k with a Baldwin filter and Mobil synthetic oil.I do a filter swap and top-up at 5k.I change the fuel filter every second oil change.This has been working for me.Nice truck,you'll like it even more when you pull a trailer with it.

gator's 99TA

iTrader: (2)

ours has made 405/800 at the rear wheels with the hot juice with attitude monitor. www.edgeproducts.com is your source. as for stacking them, well like X hitman said, no way a stock tranny will even take the reg hot juice. stacking will push you into the 450/950+ at the rear wheels. but the computer will dfuel like crazy till you build that tranny. but we love ours. that is our only mod. not even an intake or exhaust yet. oh and they add 2+ mpg on the highway as well.

the GM Diesels are the most car like in terms of handling and comfort.

www.thedieselplace.com is one of the best sites for duramax/allison combos. it even has a sticky post for maintence and FAQ.
www.thedieselpage.com isnt bad either but you have to pay to be a member, not read though.

SsZERO

I looked at that Edge website and it said that a stock tranny could handle 900 ft-lbs? Is this true, ore is that in some unusual condition for only a couple seconds? What does dfuel mean? Does that mean the fuel flow to the engine is cut off? Another thing I was wondering is why does driving in 4x4 mode on dry pavement not recommended (in the manual)?

cstchevy

I know only a little about these, but I have seen a video of a regular cab long bed 2wd diesel with propane injection and the edge attitude running low 11's . They had mounted slicks on the factory rims and had to do some stuff to the tranny and rear springs to handle all the TQ they were making. they spent a total on performance parts of like $2000 and that damn thing to off like a dragster, wish I still had the sight. My next truck will be a duramax quad cab 4x4.

gator's 99TA

iTrader: (2)

it will cost you more than 2K to run those kinds of numbers. i promiss. maybe 2K in the power addons. tranny parts are expensive.

defueling is when the pcm shuts down the fuel and the motor falls on its face. diesel makes its power through the fuel (and lots of boost) since there is no spark. defueling is the same as our torque management. it saves the trannys between shifts. remember GM designed these trucks to go 200K+ miles.

Edge and others believe the tranny can handle 900 ft lbs (at the motor) with an easy foot. now if you are pulling loads or racing it everyday, ofcourse it wont last at all. but i can kill a stock tranny with stock power in that fashion as well. will it last forever? nope! but it will hold on. my pops drives like an ole man 95% of the time, but that 5% is pure hell! refer to my last post on his dyno power. and his tranny hasnt limped ONCE yet. put a crazy person;s foot there and a different story will result.

4wd operation on dry pavement could result in quickly worn driveline parts. lots of stress on those locker differentials and transfer case. besides, why would you run 4wd on dry land anyways? other than to drag race!

cstchevy

that's what I meant on jsut engine upgrades. Yeah those tranny parts are expensive but it's a must have real quick when you want to get everything out of your diesel truck. I think the guy was making like 550 hp trw and 1250 tq or something like that it's been a while.

SsZERO

What does it cost to build up an allison tranny? What actually needs to be done to build it up? If I got a 4" exhaust, would it be a lot louder than stock? I do not want my truck to be loud, since it is my daily driver. The stock noise levels are fine with me.