slightly off topic, im going to be looking for some more power out of this thing soon. Truck pulling season is right around the corner and i intend to run this thing for a full season if i can manage it. Going for stock diesel Never done it with this truck before but its going to need the rear end locked up and im pondering a air locker in the front. Daily driver, fifth wheel hauler, boat puller, sled puller... mmm diesel...

 

Thats a fully loaded C3500 X-cab dually, no FWD.
I think she's @ 7800 or 8800lbs empty, been years since she saw a scale or that Ive seen my feet for that matter. j/k


Take a video with audio, post it on youtube... let us hear this screamliner..

FWIW, my alt pulley measures 2- 9/16" across the face. And the slightest fuel supply deficiencies can dramatically affect mpg as well as overall performance.

If my trans didnt shift till 3500RPMs, it would toss the driveshaft out the side or who knows what but somethings likely gonna break....
From a dead stop and punch it to the floor and hold on.. Once it manages to get traction and speeds off, around 3000rpms the trans shifts firmly.... All four tires duallies sound off with a loud chirp in 2nd and scratches at 3rd.
Discovered that right after installing the DE 4" Exhaust.. Top to bottom of the on-ramp to the interstate is hardly 1/8th mile, Im already rolling at 80mph before I get to the merging area.. People usually get over, truck sounds like hells fury from behind when sticking your foot in that get up and go..

PCM monitors engine RPM via the CPS. The alt only supplies the I/P tachometer..
If you have a scan tool, you can compare the I/P with the PCM reading..

550.1 miles per 27.0 gallons= aves 20mpg and some change...
Thats running 75mph from pump to pump, haulin' *** up-n-down the interstate with just us and our luggage.
Hauling or towing heavy depends alot on aerodynamics and terrain more so than overall wt.. My 24' enclosed cargo trailer aka the tool shack was like towing a 12-15,000lb brick, on flat ground doing 55-60mph, that rolling billboard still squeeked out 15ish mpg.. Climbing the mountains,12ish mpg..

Seriously.... I'd expect far more mpg from my diesel on a bad day than any of my bigblocks on a good day under the same driving conditions.. All Im sayin..
We've done this mpg thing a many times when we used to keep tract of mileage too...


As for the truck sled pullin, IMO thats really bad idea if this is your daily driver..
Even going 4X4 offroad'n on wekends is risky. If I had a dollar ever time Ive had to pick up employees on monday who tore there pooh up out- drag racing, puddle jumpin', dune dasher, ditch diving, muckin' it up at the mudpit, WTFE often after a few to many brews and goated to act a fool, aka lets get stupid people... Dont be that guy..

Thats why I didnt buy 4WD, I knew Id have to find its outter-limits then use that as an excuse to 'beef' s'it up so that I can go out and try to break it again the next weekend then thrash about attempting to patch up the carnage, self inflicted most often.
That was the point of us buying a new 'diesel' work truck. Free'd me up to repair other company trucks, or tinker with my hotrods and other toys, or jump in daddies truck and take a road trip to WTFE.....
Who would have imagined the 6.5 work truck, admittedly a contractors cadillac would quickly became the entire families favorite road trip vehicle, most comfortable ride with the 800-1000lbs of tools stowed securely under the tanue cover. It was certainly alot 'sportier' than the wives minivan or the daughters Breeze.. Then it was routinely commandeered for grocery shopping to runs to the mall. Now I have to ask if I can use my own s'it.. 'magine that....

 

our alts are the same size, i was going belt surface to belt surface not outside to outside. Its not my only truck, its just my favorite for commuting. I still have a 6.5 powered s10 i can drive . For some context here im a master ase tech at a transmission shop with a near masters certification from gm. I have a parts truck and a spare 6.5 with a spare 4l80e. Last year i ran a season of figure 8 racing at two local tracks and came in third for the season. Before that i drag raced for a number of years and dailyed that car just to rub it in. I ask allot from my vehicles but they get allot in return. Its going to be sled pulling, thats not part of this debate

Also these trucks are programmed to shift at 3800 under full throttle, not 3000 you should get that checked out. My point on shift speed and idle speed was that it is reading close and maybe even low at minimum and maximum, i have reason to suspect it is close in the middle too. But like i said i will be comparing tach reading to scan tool readings on monday for some more information.

 

http:// https://youtu.be/ghCoGXG7jKU

My a team turbo and spool valve mounted on another truck for dyno purposes.

Sounds like a big block with glass packs and a banshee howl out the exhaust.

An a team equipped truck with a 22-2400 rpm tripple disk converter sounds like a stock car racing diesel. Ears will bleed!

 

that link didnt work for me. We have been putting some of those triple disk convertors in dodge tranny's lately and with the pressure turned up the convertor can come on harder than a shift, pretty impressive stuff. Not sure i would want my truck to sound like anything that has glass packs.

 

I call it a cammed 454 with 24" glass pack vs a straight pipe GM turbo that reminds me of a 350 with 12" glass packs.

It's deep but has a good rumble.

 

scan tool verified my tach is right on all the way to redline. Went through and built my own "feed the beast" i had no idea how much high rpm power i was losing through that tiny hose. Im going to need to order up their fitting for the top of the ip but everything else was stuff i already had at work. Even with the stock inlet fitting it is still a huge difference, its still building boost at redline instead of losing it.

 

Not doubting you but is your speed GPS checked?

You might have 4.56's but that is a little low for 4.56's and high for 4.10's but tire sizes could cause that to vary.

Smallest to largest common dually tires:
225/75 r16 (bout 29")
215/85 r16 (same height as 245/75)
235/85 r16 (same height as 265/75)
255/85 r16 (same height as 285/75)

 

cruise set on 75. gps read 74.4 this morning. 225/75r16 tires.

 

cruise on, flat ground, taken within moments of eachother.