Potential of the Dmax

tbirdfiend281

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so reticently ive been starting to research the purchase of a new truck, this purchase will happening in about a year to a year and a half.

while i know what kinda power/sound/potential/driving characteristics the ford trucks have since i deal with them, o, all the time, im curious about the duramax powered chebby truck, i have driven an 06 LB7 or witch ever truck has the 350hp motor that was a crew cab with a SRW and a small utility body on it. i was impressed at how quiet the truck was and how powerful it was compared to a stock 6.0, the ride quality also seemed to be better then the ford.

all that being said, if i where to be in the market for a duramax, not sure if i wanna crew cab drw or something in a srw package, but witch duramax year(s) where the best for purchasing overall. i have seen a few 03-04s siting around my price range, but price isnt really an issue, its more mileage and equipment im worried about.

but ya, witch is the 350hp motor, and is this the motor i want, or is the 300hp pretty much the same motor? im not famaliar with the duramx's but i am very strong on understanding diesel engine performance, so no need to tip toe around technically terms....

any input and/or help is mutch apreaciated

im also considering Cummings DRW 03+ trucks only, im not a fan of the older body styles vs the 03+ ones, plus they are plentful and can be had significally cheaper then the other trucks
 

TLBREWER

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I can lay out the basics for you, but I may be a little off on specifics.

2001-04 was the first gen Duramax RPO LB7. This was the growing pains engine. Had problems at first with glow plugs and controllers, and I believe head design. These are probably the moist abundant and have just about everything available possible from the aftermarket. Output was around 300hp and 520 ft/lb torque.

2004.5-2005 brought about the first LLY version. Output was 310 hp and 590 ft/lb torque. This engine was equipped to meet 2007 emissions standard with EGR valve, CAT, and some programming changes.

2005 LLY was the upgraded version of the same engine. Biggest change was a new 32 bit Bosh ECM. Power output went up to 605 ft/lb torque with hp the same.

2006 LLY and LBZ. The year started with the upgraded LLY. It had an improved block which would be shared with the LBZ later in the year. I believe the biggest changes were an improved EGR system and the addition of the variable geometry turbo. Power output remained unchanged.

2006-2007.5 LBZ. This is the one I have and the pinnacle for the Duramax before the dreaded DPF systems came about. Same block as the '06 LLY with a bunch of internal upgrades to raise power to 360hp and 650 ft/lb of torque. Aftermarket support is slowly coming around for these engines.

2007.5 LMM :puke: No seriously. Don't know much about them other than the DPF system and corresponding exhaust changes. Power output is about the same as the LBZ. A lot of them on the road now and haven't heard much in the way of negative feedback.

One thing to remember also is that the '06 LLY and LBZ's only came with the Allison six speed tranny. So if you want a manual tranny...oh well. I'm not sure why since a ZF-6 would be a natural choice and wish it had been available because I prefer manuals. The Ally is a pleasure to drive though. One thing to remember is the LBZ output is near the max allowed for a stock Allison so modifications should be chosen carefully before upgrading the tranny. Another thing that is kind of weird is the Allison 'puter actually controls the ECM to some extent. Seems backwards to me.

I think the LLY has the biggest aftermarket support and has the bugs worked out from the LB7. The earlier one is also a bit simpler than the LBZ. This is probably the the version I'll be looking for when I get ready to restore and re-power my '66 Impala SS.:D

Hope this helps a little.

Tom
 

tbirdfiend281

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I can lay out the basics for you, but I may be a little off on specifics.

2001-04 was the first gen Duramax RPO LB7. This was the growing pains engine. Had problems at first with glow plugs and controllers, and I believe head design. These are probably the moist abundant and have just about everything available possible from the aftermarket. Output was around 300hp and 520 ft/lb torque.

2004.5-2005 brought about the first LLY version. Output was 310 hp and 590 ft/lb torque. This engine was equipped to meet 2007 emissions standard with EGR valve, CAT, and some programming changes.

2005 LLY was the upgraded version of the same engine. Biggest change was a new 32 bit Bosh ECM. Power output went up to 605 ft/lb torque with hp the same.

2006 LLY and LBZ. The year started with the upgraded LLY. It had an improved block which would be shared with the LBZ later in the year. I believe the biggest changes were an improved EGR system and the addition of the variable geometry turbo. Power output remained unchanged.

2006-2007.5 LBZ. This is the one I have and the pinnacle for the Duramax before the dreaded DPF systems came about. Same block as the '06 LLY with a bunch of internal upgrades to raise power to 360hp and 650 ft/lb of torque. Aftermarket support is slowly coming around for these engines.

2007.5 LMM :puke: No seriously. Don't know much about them other than the DPF system and corresponding exhaust changes. Power output is about the same as the LBZ. A lot of them on the road now and haven't heard much in the way of negative feedback.

One thing to remember also is that the '06 LLY and LBZ's only came with the Allison six speed tranny. So if you want a manual tranny...oh well. I'm not sure why since a ZF-6 would be a natural choice and wish it had been available because I prefer manuals. The Ally is a pleasure to drive though. One thing to remember is the LBZ output is near the max allowed for a stock Allison so modifications should be chosen carefully before upgrading the tranny. Another thing that is kind of weird is the Allison 'puter actually controls the ECM to some extent. Seems backwards to me.

I think the LLY has the biggest aftermarket support and has the bugs worked out from the LB7. The earlier one is also a bit simpler than the LBZ. This is probably the the version I'll be looking for when I get ready to restore and re-power my '66 Impala SS.:D

Hope this helps a little.

Tom

helps alot, so the lb7 has no emessions system AND a wastegated turbocharger???

lbz's seem to be a bit pricey, i didnt see any in my 200 mile radius under 35,000 search on autotrader, so they may be out of the question, but hey, you never know in a year or so, maybe theyll be in my price range

the allison is at its max with 360hp? your kiding me, everyone tells me how awesome that trans is, well anyone who into dmax's it seems like...
 

tbirdfiend281

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I say you have lost your mind!!!:backoff

and just because i buy a non ford doesnt mean i dont love my old blue, its worth to much to me vs what its honestly worth to just ditch her

im just weighing out my options, ive been around fords and to tell you the trueth, i may be geting tired of them a little :dunno
 

h2odrx

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and just because i buy a non ford doesnt mean i dont love my old blue, its worth to much to me vs what its honestly worth to just ditch her

im just weighing out my options, ive been around fords and to tell you the trueth, i may be geting tired of them a little :dunno

I can understand, i saw a article in one of the Diesel mags where they were towing 10k i think and heard a clunk at around 60mph nothing was seen so they drove it on home. broke the crank just behind the front two cylinders. the front two ran the externals and the rear six ran the tranny. I think it was a LBZ? so I'd say it is a tough engine? never did hear why it broke? anybody see that one?
 

LOGANSTANFORTH

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most of the top pullers out there are running a mix match of duramax parts to make pretty hot motors, LBZ rotating assembly in LB7 blocks, all kinds of stuff, all of the stock trucks, no matter what RPO code the engine has, will make about the same horsepower with a stock turbo, a shade under 500, with a normal EFI Live tune. the tranny wont like it and it will die a slow horrible death, then you can buy a full set of clutch packs, valvebody and 5 disk billet conveter.....yeah it snowballs pretty quick, oh and its CUMMINS not cummings.....sorry, just giving you a hard time.

LB7's had injector cup seal and injector problems
LLY's had cooling problems in the first generation motors in some trucks
LB7 and both generation of LLY's have horrible problems with the dual mass flywheels in the 6 speed manuals
LLY second generation motors use the LBZ computer system so you got to use the same tuning you would with a LBZ
LBZ's are good motors but are on the verge of hurting the tranny
LMM's have way too much emissions crap on them.
 

tbirdfiend281

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im very disapointed an allison, the transmission everyone said was the greatest cant handle much more power with an lbz in front of it...:(

you wont see me with a stick shift truck, im not a fan of stick in a truck

that g seems to have magically apeared in there, im fully aware of how to spell cummins :(

i think im going to be looking for an LBZ if i do go duramax
 

TLBREWER

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helps alot, so the lb7 has no emessions system AND a wastegated turbocharger???...
the allison is at its max with 360hp? your kiding me, everyone tells me how awesome that trans is, well anyone who into dmax's it seems like...

It's not the 360 hp it doesn't like, it's the 650 ft/lbs of torque that are near it's stock limit. I think they're good to about 750ft/lb before the slow horrible death that loganstanforth mentioned. These engines are easily capable of 1000lbs of torque without tearing into them...but you must take care of the tranny first. ATS has everything you needLOL . Let's start spending your money before you even buy the truck.:rotflmao

Another thing to consider is which chasis you want. My truck is a 4X4 crewcab 3500 SRW. My buddy has an identicle truck(except for color) only it's a 2500. There is a noticable difference in ride height (partially due to tire size) and mine rides a LOT stiffer, which I like. Remember though, this is comparing stock vehicle to stock vehicle.

Tom
 

tbirdfiend281

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i didnt kno they made a SRW 3500 chevy, i always see 3500 dualies, and 2500 srw.

im aware of the difference of 3500-2500, ford has the same deal a 350 will sit a good inch or so higher then a stock 250 when parked next to each other, and also same tire size. i know the chevies is mainly cuase of the tire difference.

i think a 3500 DRW is in order maybe an 02, i saw an 01 3500 EC DRW auto 4x4 on autotrader with 42k on the ticker for 25g's, thats an amazing price for the truck.

so i think for the pure fact they dont have any emessions but still a nicely rated power turns me on to them. even with a few failures here and there, it cant be all that bad

i like the looks the best also, the front grill on an 01 is the one i really like
 

apextrans

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I gotta tell ya, the best truck I've owned to date (& i've had more than a few) was my 2002 2500HD crew srw. I had a 2000 2500HD Extended cab before that with hte 6.0 vortec. Believe it or not the 6.0 ran better. The 02 wasn't a diesel but it had the 8.1 votec. Those trucks rode EXCELLENT, were tight, quiet, comfortable, & trouble free. I mean NOTHING wrong with them. Had to sell the damn 02 to buy my freakin house. I have also considered the GMC option when I replace the Super Duty. I like the front end on the GMC's better that the Chebby's. Problem is I may need a 450 to pull a car trailer. I've always like the 02-06 body style but have never looked into the d-max at all. I'm interested.
 

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