HAHAHAHA!!!! That was a good one! Not disputing it, it was just a funny way to put what you're saying.

I'll say this: It seems the duramax has the ability to rev pretty high, which helps it make horsepower. The ability to not have to shift as early is nice, because it allows you to keep the torque multiplication advantage of whatever gear you're in for longer.

Though it's not really what we're talking about here, I can assure you that the torque curve of my 12v dually does not resemble any form of antenna. One one pull, it hit 500 ft/lbs at 1250 rpm, hit 920 at 2200, and had a nice fairly slow decrease beyond that. This is on an inertia dyno that's NOTORIOUS for reading low. I know, you're talking about the common rail here. Just out of curiosity, what was your torque down around the 1250-1300 area?

 

Just a thought along the lines of modifying these engines-I wonder how hard it would be to convert a duramax into a gasoline engine. It's not derived from a gas motor, so you probably couldn't find heads with sparkplug holes and a reasonable compression ratio to go on there. If you could somehow pull this off, can you imagine the amount of nitrous you could put to it? As long as you didn't overrev it too much, I'd think the bottom end would stand up practically forever to heavy nitrous use. Folks occasionally do that with the otherwise-useless olds 350 diesel. They take a 425 olds big block crank, bore it a certain amount, and end up with, of all things, a 442! I hear that it works really well as a nitrous motor. Anyway, I digress...

 

Well...I couldn't find any runs from an LBZ Duramax but here is my stock 600. It obviously has come a ways since this run and I hope to have it on the dyno again soon. I just need to get a few more things in that I have on order that haven't gotten here yet.

 

TQ at 1200. Not very good. Right around 400ftlbs. The power curves of those twin trucks I saw where odd to me. Those to fellows where so happy with their peak numbers. I think they missed the forest for the trees IMHO. If my truck put up graphs like that I would be not very happy. From my days of drag racing gas cars I have learned that peak power means very little. Power band is far more important. Both those twined trucks where CR CTDs. I guess the strange graphs where caused by stacking. I really wish EFI Live would come out with a update that would let me program the CR CTD and rescale the graphs so I could make it rev. In the Duramax community the boxed tuners and stacking are pretty much a thing of the past. Why fool it when you can make do what ever you want.
As far as connverting to gas. I do not know if there is enough room in the injector hole to make it a spark plug hole. You would need to fab a intake manifold, use a crank trigger, and change the cam


staarma
That looks good to me. I am suprised that peak horse power is so late in coming. My trucks peak horsepower is around 2500 rpm and stock it was at 2200 rpm. Looks to me like that thing needs some more revs.

 

Well they say if it keeps building power then keep revving it. It does look like I could get away with another 500 or so RPM. That may be in my future with a cam and some other components. It does make a different kind of power than my 2000 24 valve did that's for sure. I'll post a new graph after my latest round of bombing attempts.

 

Be careful comparing dyno charts/graphs/numbers. They really shouldn't be compared unless they were taken from the same dyno, and should be taken on the same day.

 

johnboy6.6,u r BY FAR a minority. in fact, i think u r the only manual dmax guy ive read on this site? I could be wrong. im not tryin to dis the dmax,just pointen out that the allison a huge part of the dmaxs prowess.my 05 CTD with the 4 speed auto is REAL strong,with a 6 speed auto behind it.....OH BABY!

 

Yeah, the Dmax/ZF6 is a real rare combo. Our friend had one, and when he tried to track another one down, none of the dealers could find one in CO. Who knows, it might be worth somethin way down the road.

 

Your both very right. My truck is real rare. If what I was told was correct. In 2002 GMC only 10 Crewcab longbed 6 speed trucks, and I have one!
I just wanted to make sure you know that the Dmax does just fine with or without the Allison. I to am looking forward to taking a 6.7CTD with the Aisin tranny for ride. Sounds like a sweet combo to me. Also I am not on here to be a Troll. I am hear to learn as much as I can about Diesels. I have learned a lot from the few CTD guys that post regular on the DP. That caused me to sign up here. I have learned a lot from reading threads on this forum. I have been doing a lot of reading about mechanical pumps and how they work. My truck is getting to the point where I will most likely need another truck to haul it to the pulls. I might be a Duramax, it might be a Cummins, no way will it be a Powerstroke.

I think what everyone needs to remember is that it is real hard to compare these two engines. They are different in how they do things. Then you start changing trannys around it really gets hard. Like I said earlier it comes down to what feels best to you.

 

I have put more then a few miles on a 2001 24v. It ran out of breath at about 2200 rpm. That was a big reason for buying the GMC. It pulled hard up to the 3200 rev limit. Now it pulls like a **** clear past 4000 rpm.

 

johnboy6.6 no hard feelings here,im hoping to learn from u dmax guys as well. since u guys have been runnin the pilot injection alot longer. its just when fredw and lbzpower come in here its like they talk down there nose at us CTD guys. again, i could be wrong.fredw came in here awhile back and was runnin his mouth about how the LBZ was so much faster and BETTER than the CTD was,but neglected to mention that at the time there was a recall on the LBZ for glow plugs fryin the motor. that just got to me .

 

now is their anybody that can overlay the cummins and LBZ http://www.dieselplace.com/forum/att...2&d=1134792615

am i reading this right or does the duramax make more tq down low than the cummins stating it will hang on longer on a hill before needing shifting

 

I see your point. Think about this. 2001 2002 GM injectors are noted for problems. Mine are all original. 75k+. All kinds of big freaking tunes. The thing you have to think about is that with any brand recalls are hit or miss. A guy who has a problem is going to make far more noise than the guy without. Just look at the TSB list for GM trucks. Most of it is stupid crap like squeaky doors and knappy seat covers. My buddies 2001 CTD has 475k miles on it original stock injection pump and lift! That is not suposed to happen either. The only real trouble I have had with my truck was the stupid Dual Mass flywheel. I replaced it with a billet flywheel and dual sintered iron disks and life is good!

 

Anni2vader,
I have never talked down the Cummins, give me a break. Rich started this post with the Duramax is the crappiest motor ever. I disagree, along with several other D'max owners. It's just some of you over here have to claim Cummins is the best no matter what. If someone else mentions another diesel engine or states it makes more power, it's like we're insulting your mother. I mention Dyno's and they don't mean anything, because it's not real world testing. Then XLR8R gives Dyno numbers of an LBZ 570 tq and uncorrected numbers of a Cummins 600 @610tq, so he uses SAE numbers for a D'max and Uncorrected #'s for the Cummins, yea that's honest, so it must be me looking down my nose at the cummins. I mention that the D'max did better then the Cummins in a magazine test pulling 12,000lbs, after some of you say the D'max can't even pull hills.Then Staarma and mooseguy mention that the magazines are rags and idiots. Lets just be honest I've never said one thing over here to insult your trucks, I just disagree with your comments and opinions on the Duramax. I have only been honest, Edmunds did the shootout not me. On SAE corrected numbers a LBZ usually puts down 540-570 RWTQ. A Cummins 600 auto will be 495-525RWTQ, depending on type of dyno, altitude, temp,.... Bottom line is D'max puts out more. I never once said this meant the D'max was better, it was mostly supporting the fact that the D'max isn't as weak as some of you would like others to believe, but then some of you seem to take this as an insult or an attack on the Cummins. I think both motors are pretty equal and both should be pretty even pulling/hauling, but no not you guys, and even after Dyno charts and articles showing the D'max is on par with the Cummins or did a little better, somebody else needs to go the longevity route. How Cummins is time tested and the D'max is japenese aluminum crap, or see me in 300,000 miles and lets see how you feel about your D'max then.
So guy's answer me this, why do you feel it is so necessary to say the Cummins is better then the D'max?? and why when anyone brings up any type of supporting information about the D'max being a good truck or making good power, it is always incorrect or means nothing.

 

LBZ, you got pretty ugly at one point to a particular member. I already pointed that out, no need to rehash that.

The thing you're right on is the excuses and backpedaling-a lot of cummins fanboys do that. The thing is, "see me in 300k" and "trucks aren't for dragracing" may be true, but they're not usually germane to the discussion at hand. To me, that makes them excuses. If an LBZ will beat a stock like-year cummins in a drag race (which I'm quite sure it will) then it will beat it in a drag race. End of story. That doesn't mean a cummins guy must then go and trade his dodge in on a chevy, it simply means that the chevy is quicker in a drag race. I personally don't feel threatened by that fact, even though my wife and I own an '06 dodge. I knew the dragracing stats when I ordered the truck-I just didn't care. It may well be that a stock auto chevy will outpull a stock auto dodge, at least in terms of acceleration. That's ok, too. I know the reasons I bought my truck, and they still apply, regardless of what tests and magazines say. I have no intention of getting rid of our new '06 anytime soon. I'd like to see 500k or more out of it, with minimal problems. That's why I bought it, and that's why dragracing stats do not bother me.