Does anyone know what the rear wheel torque is for the LB7 and also for the LLY?

The published figures from GM at the engine are 520 lbs for the LB7, 590 lbs for the 2004.5 LLY, and 605 lbs for the 2005 LLY.

I was recently told that a stock LB7 will actually dyno at the rear wheels with a higher number than the LLY. Is that true? Also, is the 15 lbs difference in the LLY factory numbers basically a paper change, or will it show up on the dyno?

Thanks.

i had my truck, bone stuck other than exhaust, on a dynojet a few months ago. I got 375 ft/lbs of torque. I was surprised and sort of let down. Some say the dynojets read way low for the duramax though. I dont know what to think.

On a Dyno Jet my truck usually rolled between 420-440 RWTQ......

2002 LB7.stock tranny too........

375 seems really low.......:confused:

http://dieselplace.com/forum/showthread.php?t=18495

Look at post 78 and 79
This was on a Mustang Dyno

mine usually runs 242-244HP and 440 tq in stock config. i've heard of lly's running 260 stock. i know my buddy

246rwhp 440tq here. LLY

Anyone know what the deal is with the published rwhp/tq numbers versus actual dyno results. Why are the dyno results always so much lower than what GM publishes?

so what the hell? is there something wrong with my truck? what could it be? all the other guys there said nothing was wrong with my truck and that it was normal. They were all dodge guys though. The only other Dmax was john from DPS, he reassured me that nothing was wrong too. Oddly enough me and a few other guys also thought that my truck broke traction just a hair. I dont know how much effect this could have on the accuracy of the dyno reading but imagine it could be a minor factor. Im thinking of installing an Edge attitude but the only baseline i have to go off of is 214.5 hp and 375 torque. Id like to figure it all out and get it nailed down so I can see the benefits of any upgrades. As usual any and all opinions are appreciated.
thanks
jake

Buy one hour of 'Dyno Time' and see for yourself. Run all the gears and try different approaches for HP & TQ. Get the truck and trans a little hot when you do the tests. It's 100 bucks that will give you a solid baseline as well as solve your worries for a very long time.

Anyone know what the deal is with the published rwhp/tq numbers versus actual dyno results. Why are the dyno results always so much lower than what GM publishes?

Brochure HP is at the crankshaft with the engine out of the vehicle.

When you put the engine in, transmission, driveshaft, rear gears, axles, tires all suck up HP.

If you pulled the motor out of a GM car/truck, you will hit the brochure HP if not higher.

Keep in mind that a 426 Dodge Hemi rated at 425HP for the street hemi put out about 340RWHP back in the late 60's. We have lightly modified diesels that exceed that by a wide margin.

so what the hell? is there something wrong with my truck?

There may be nothing wrong with your truck, it could be an invalid test reading. There was a thread about a month ago discussing the pros and cons of the various brands of dynos. I do not remember the details, but I got the overall impression that not all dynos are created equal. You might try doing it again, but on a different dyno.

If the Dodge and Ford trucks hit their numbers at the same time on the same Dyno........ put yours back on and try it again.

I was looking at a Banks brochure and it had chart showing approximately 460 ft lbs on a 2001 stock truck. Edge also has a chart but the scale is hard to read and it did not list details on the engine. (I would guess it is a LB7 with 430 ft lbs.)

So, here is what we have so far:

440 lb - 02 LB7; GMC-2002-DMAX (Dynojet)
440 lb - 02 LB7; Diesel Power
460 lb - 01 LB7; Banks

375 lb - 04 LLY; JMG343 (Dynojet) (Problem???)
440 lb - ?? LLY; MCRAT
503 lb - 05 LLY; BKTOOL (Mustang)
506 lb - 04 LLY; YamahaGrizzly (Per Link)

The LB7 trucks seem to be consistent, but the LLY numbers are all over the place for some reason.

Any more?

I was looking at a Banks brochure and it had chart showing approximately 460 ft lbs on a 2001 stock truck. Edge also has a chart but the scale is hard to read and it did not list details on the engine. (I would guess it is a LB7 with 430 ft lbs.)

So, here is what we have so far:

440 lb - 02 LB7; GMC-2002-DMAX (Dynojet)
440 lb - 02 LB7; Diesel Power
460 lb - 01 LB7; Banks

375 lb - 04 LLY; JMG343 (Dynojet) (Problem???)
440 lb - ?? LLY; MCRAT
503 lb - 05 LLY; BKTOOL (Mustang)
506 lb - 04 LLY; YamahaGrizzly (Per Link)

The LB7 trucks seem to be consistent, but the LLY numbers are all over the place for some reason.

Any more? Jason's ( yamahagrizzly) 506 and my 503 were run on the same day, same dyno. Maybe 1 hour apart. These were on a Mustang Dyno. Tony ( GMC-2002-DMAX ) was also there and ran his truck. I'm sure with all the times and on all the different dynos he has run his truck on, he might be able to tell just how close his numbers were that day as compared to what he sees other times. What kind of dyno did McRat use?
Also look here http://dieselplace.com/forum/showthread.php?t=18342 at post #73. This was run on a Dyno Jet 2 weeks after my run on the Mustang.

Dynojets do not sufficiently load the turbo over a long enough time to truly show what a diesel engine is capable of...........although it is a good tool a Mustang or Superflow is usually a better way to test.

I have been on at least 4 or 5 different dyno's.........

In fact at times in CT 3 or 4 ------->>>01/02/03 LB7 trucks would appear to be the same exact truck on a dynojet.........RatDoc and I have similiar trucks and tunes and would roll within 1/2 hour and see almost identicle results.......because the tests were conducted the same each time.......

In RI it was the first time on a load cell for me........with the new tranny and the Xtreme...........I did not even bother baselining my truck as it was done so many times I did not care to do it again.........

That day I had a best of 496 for Hp on one run and a best of 1037 TQ on a different one although the hp on that run was 490 RWHP.........

The dynojet IMHO will allow a higher spike or a discrepency because it offers resistance over 3-5 seconds..........instead of 14-20 on a load cell......

I advise anyone who wants to get more info to contact TRIPPIN as he is the only person I know who has has 160+++ dyno pulls and he is methodical in his testing procedures.........or John Kennedy as he has a Superflow in house and ran all the trucks at his GTG in September.....

In fact I called him (TRIPPIN) from RI and had him speak with Buddy the Mustang Load Cell Dyno operator and we altered the testing to a more scientific method where we saw repeatable results........

My best advice is seek a competent shop with an experienced dyno operator..........a TECH II is a must for 4th gear commanded and TC lock......Then you will see consistancy.......

Good Luck,

Thttp://www.dieselplace.com/forum/images/smilies/cool.gif NY

If everyone of you took your trucks to another dyno you would get different numbers for the same truck. Dynos are for comparison. Two identical dynos WILL NOT read the same.

265rwhp and 495 rwtq on a Superflow