It works with a good tune and the help of a little added compression.

Me and Zippy rode in the HD with the crew to the s-series nats this weekend. We were twoing a ext. cab extreme with the back of the truck filled to the brim with parts tools and a 55gal drum of race fuel. estimated wet gross weight would be around 12k+lbs. The truck is a 2002 ext cab short bed 4wd 2500hd with the stock lq4 short block. The cam is a TSP 233/239, 595,603, 113lsa. The heads are 241 casting MTI stage 2e's. Stock manifolds and intakke manifold yet. 3.5" single exhaust. the truck went 14.88@96.x last time to the track. We pulled in overdrive all the time it downshifted about twice on the way (500mi) and a few more times on the way back. Towing speed avaraged about 83-86mph (2600rpm or so). We went all the way up to 105 and stuck here right at 95 a couple of times for some longer streches. It would go into overdrive at 50mph (1600rpm converter locked) and it would cruise right up to speed without a downshift. We got stuck in some nice traffic jams it idled pretty damn nice at 625-750 depending if the ac compressor was on or off at the time. We got anywhere from 10.6-11.5mpg while moving along pretty darn fast too.

Just goes to show if set up properly you can have a pretty mean cammed na truck and still ahul a lod pretty well too. All in all it towed better then stock and got better millage then one would expect at the speeds we were running.


TJ

 

hmmmm what was the rearend gear ratio?

 

It's an HD...it'll have a 4:10 rear probably

How was the low-end grunt (idle-2000rom) off the line towing ?? (I've considered a cam this big but I'm worried about the weight of the truck alone), and comparing it to a stock cam'd 6.0 how's it pull when not towing ??. The reason I ask is I'm suprised that it's not running faster with that cam/head combo...on my baby-cam/polished ls1-head combo I run just a touch faster than that so it makes me think the low-end has to be pretty weak to only net a 14.88.....I'm not criticizing your truck at all either, just curious

 

It is a little sluggish coming out. The head and cam combo would do much better at the track with headers and intake, along with a converter too. The MPH is there though. You can get a load moving with anything, I like the hp's for when towing and you make that downshift when need be.

 

that HD hauls *** for sure. You got z-rated tires on the trailor ? LOL. Traffic jam? you must have got caught behind all those powerstrokes slowin you up!

 

Zipp was wondering about the trailer tires....

 

I was a bit concerned about the trailor tires, but other than that it was just another day down the highway.

 

My HD pulls 2500 RPM in O.D., locked in @ 75 with 3.73's. Maybe he's got 3.42's ??

 

The truck has the stock 4.10's. When you get a 2500HD, there is no gear option for the 6.0L. You get a 4.10 or a 4.10. lol

Calculating it out with the 30.6 tire height for the Commercial TA's that are on the truck 2600 rpm is 77mph. That would be why he said about 2600rpm. it was likely closer to 2800, but between tach error and speedo error as well as not looking for exact numbers, it was close enough.

 

Right that is why I said "about 2600".