Is the LB7 the ultimate?

[More Power]

The 2002 LB7 Duramax keeps turning up in the winners circle at diesel events across the country, and we've read of 900-hp LB7s and some running factory turbos making more than 700. Even though the LLY & LBZ offer more power/tq from the factory, these newer engines haven't gotten all that close to the level reached by a modified LB7.

What's the issue? VNT turbos, lower voltage injectors, newer ECM/programming, EGR - what...

I've heard of a few different performance Duramax engines currently in development that make use of the newer (some say better) LBZ block, pistons, and rotating assy, but will get LB7 heads, LB7 injectors and LB7 electronics.

Jim

[Mark Rinker]

I sold my '05 in favor of the higher mile '01 and '02 for towing duties, and can tell you that my favorite is the '02. It puts the most power to the pavement, and yields the best overall fuel mileage. Upgrading it with JK's tune only made it even more enjoyable to tow with.

After jumping from truck to truck, trailer to trailer, and load to load, I can tell you that there is something significant about that year, especially compared to the '05 - by any measurement. The difference between the '02 and '01 is mostly mileage doing the same work. Swapping the spare '02 ECM (with stock programming) into my '01 did not change seat-of-the-pants power or average mileage, so my crude conclusion is that its 'something mechanical' with the 2002 year.

Question: Are the 2003's similar to the 2002's in performance?

[madmatt]

I'm currently shopping for a spent 02' myself for that very reason. I'm gonna start building another pulling truck since I've been rulled out of every truck pull I showed up at w/ my Cat powered 70' C-20. That and the fact she threw a fit on the dyno last month that resulted in another seized piston!!!!!!! Yes, IMHO for "BIG" power Duramax builds the LB7 is the way to go.

[Buck]

The only reason the LB7 is on top now is because guys have been tinkering with them longer. I know of plenty of LLYs that will spank the LB7 trucks. EFILive has opened up a new realm for the LLY guys, and LB7 guys to for that matter. I can't wait to see how the LBZ guys fair with EFILive. LLY's rule!! www.mcratracing.com

[madmatt]

what kind of RWHP are those LLYs making?????????

[SoTxPollock]

I've never been beaten by a stock Dodge or stock Ford. Never ran against a stock LLY, or LBZ, but I do expect to be outrun by either.
Modified, thats another story. I've read about them beafing up the rods and crank and pistons and I assume that means adding more metal to those parts all of which are rotating and reciprocating components.
The fastest engines always will be the lighest components just strong enough to handle the strain placed on them. The heaver they get the more energy it takes to accelerate them up to speed. Heavy looses everytime, its just simple physics. Until one starts blowing apart the LB7 internals, I would have to pick the LB7 as winner as long as it stays together.

[colt49]

I say leave the dynos and bench racing in the shop and take the LB7 of choice and get hold of McRat Racing and run that Casper truck he has with the LBZ if you want to see the real outcome. Casper sure has some neat videos to check out on their website McRat Racing. I can't believe he puts Casper thru that many runs and it just holds together fine. That's with 4 hi 4wd in the 1/4 mile!!! The last I read from him was the time will come soon to take the motor out and measure it to check for any weak links. Christ weak links would have popped long ago if it was me trying to pound the ground like that with my LBZ. He must have got one hell of a tight truck for the abuse it takes- He says it flat scares the hell out of you in 2wd in the 1/4 mile it takes 4x4 to keep lined up I guess with all that power twisting that b*tch. It's fun to see I'm a definite fan of diesel drags now after finding all this truck trick tuning stuff.

[More Power]

I think it's great that people are devoting effort to the LLY/LBZ. But, what sort of RWHP are they developing? There's at least one LB7 truck (street legal- no less) in the 10's (see the SEMA trucks story), and quite a few street legal LB7 crew cabs have run in the 11's. :)

Jim

[JohnC]

Practice makes perfect....

Add to this, the LLY and, to an even greater extent, the LBZ are more complex animals. Give us time, and keep an eye on your rear view mirrors! :)

[colt49]

McRat's spec sheet prints that his Casper truck with EFI LIVE on #2 fuel runs the 1/4 mile in 11.7 has 674 RWHP,1400 FLB torque. Key item I noted is no Nitrous,Meth, propane or helper drugs. He states it takes Transmission mods his is Suncoast. He has 2 other trucks with nice numbers too. He gives a free race tune with a sale of his ECM as I read it. So if you want to play in that club it's not so hard to make a truck race ready for a given cost of tranny and program plus other mods that most use standard issue. McRat pounds new Corvettes it states with this truck. That must make the Vette guy go did I miss a gear or what dude!!! I'd like to see that for sure it will progress more because they are now doing an LBZ and he is catching on to this fuel system and what EFI setups it needs. I'm going to watch this California truck.

[madmatt]

Mike tomac and his LB7 crew cab are running 11.50s no drugs, well over 100k on the odo, and (last time I talked to him) he drives it daily. I'm not sure what he's making to the rear wheels but I do know what some of his 12V competitors in purpose built pulling trucks that he beats more often then not are making and can only guess he's over 800.

[More Power]

674 RWHP,1400 FLB torque. Key item I noted is no Nitrous,Meth, propane or helper drugs.

Can an LLY do it without a "helper" (non stock) turbo?

[Buck]

Can an LB7 do it MP? I know for a fact both can dyno 500+ hp! I've seen it first hand. Duramax is a Duramax run any one and spank the Powerjokes.

Bobo used to run 11's with his LLY with just his "Bobo tune" with a stock turbo (has twins now)

McRat has found out that the stock LLY turbo can cleanly burn(#2 only) a 500 rwhp tune so I guess that would lead me to believe that you can make more power than that with a stock turbo.

[More Power]

I saw JK's truck lay down 726 hp on Edge's dyno last year. As far as I know he was running a stock turbo and nitrous. Another writer told me he watched an LB7 produce more than 900 on ATS's dyno last year. Personally, and where numbers are concerned, I don't care whether the power is produced with the "help" of staged twin turbos (or large single) or a stock turbo & nitrous. At the end of the day it's the highest number posted on the dyno, the lowest elapsed time or best sled pull that people remember. Plus there is movement away from smokers. I suspect there'll be even more effort in that direction (clean performance) in the months/years ahead. :)

Jim

[madmatt]

Yeah smoke is just wasted fuel for the most part. Tomac's truck barely smokes at all.

[colt49]

This Kodiak didn't smoke bad on this 9.4 1/4 mile time. It BEAT the other numbers you state for the small trucks. This Kodiak is a meduim duty crewcab with pickup box. So get those off the dyno and put them on the track against this Kodiak and see how it goes. I don't see an LB7 under 11.7 or so stated here with a number on video. This presents a great race possibility as guys make these Duramaxes go faster. Back to the video search.

[Bobo]

It is easier to make HP with the LB7. JK has tweaked well over 500 rwhp off these on several trucks. Is the 2002 better than the rest, I doubt it. I'm not so sure a stock turboed LB7 can be beat by a stock turbo LLY, but the LBZ will surely give the LB7 a run for it's money. The LBZ is coming out swinging!