heavy haul truck, that don't like heavy hauls!

[un_yun]

First off let me say thanks to Rawze and everyone else out there for trying to help guys like me. Now down to business. I have an 06 cm870. I do heavy haul, but not super heavy.(132000 max) I have done all the stupid stuff you shouldn't do before I became aware of the library of knowledge here. I still have the mandate, but I did have international bump it up from 475 to 550. I did notice a little better driveability. seemed like a little flatter torque curve. I wonder if the put the right file in though. so I had cummins chk it, they said all was good. While there they replaced my pig tail going to my valve and dyno'd the truck. They said it was putting out 445, and that was with in spec's. So I paid and then left.(couldn't tell much difference). So I purchased a inj leak tool, and well #5 was bad. Replaced it, and maybe a little difference could be felt. I had a bad vibration at high boost. I cleaned the imap and that helped a lot! I said all that, to say this. I am still not sure it is running like it should be. I live in S.C. whom should I consult that you guys trust. I can't find anyone. Oh and my fuel mileage is in the turlet. Like 3.88, I now I am never gonna see the numbers you guys see, but 5 would be great.

[Hammerhead]

Welcome to the forum.
Fuel mileage/comparison discussions in the HH world are difficult. Trailer configurations, tire sizes, axle loads, and there are no aerodynamic equivelancies.
A freight van is a freight van. A tanker is a tanker.
We will never achieve their type of fuel mileage numbers.
A 349 excavator is not a 797 banjo is not an 857 wheel dozer, the weights are comparable. The excavator is not bad in the wind, the banjo is like a 6' diameter 30' long pipe, the 857 is like the parachutes that the military uses to drop equipment supplies. There is no way to extrapolate any reasonable comparison.
That being said, proper driving habits will maximize what you can when you can.
I run a west coast 9 axle grossing up to 190k.
My fuel mileage varies from 3-4.5, and I can some times with good conditions knock on the door of 5, but that is not the norm. When I'm empty stacked up I consistently run around 7 or higher. I'm 64-70k empty on 5 axles, and a stacked trailer is not very aero.
At 132k gross, I'm assuming you run 7axles, that's a typical range.
You should achieve 5mpg with that setup with load, wind, and terrain conditions being right, but I wouldn't expect it to be consistent.
I don't know your typical freight, but I assume it's mostly equipment that will all grab the wind differently.
I would replace the sensors that you cleaned, as the age of an 870 I wouldn't expect them to be real accurate.
Getting your injectors all working correctly will go a long way. That makes the cylinder power more consistent and the stronger ones don't have to work harder to compensate for the weaker ones.
An 870 has an air actuated VGT ipo electrical, so while they are better than a fixed vane, they aren't as good as electrical with position feedback. But there are some guys on here that are quite good at getting exceptional results.
Checking the condition of your CAC and intake tract is one if the biggest help factors. The power and economy losses here are big. Unfortunatly because of our GVW characteristics we use more torque load to climb hills and such, so this can drop off without a lot of immediate telltale signs. A 1/4-1/2mpg drop for our line of work is very easily overlooked with the common assumption that it was a little windier and this is a very realistic loss under various load conditions. This is something to not only check, but check frequently.
We can't drive like Rawze because our GVW will easily push us to too much excessive speed, but we can certainly lighten up on the fuel pedal. At 180k I'm never gonna be the first one to top of the hill, so I don't have anybody to impress, I rarely run much more than 75-80 throttle, cause I'm gonna slow down and shift anyway so why panic about it. Driving like this also keeps the heat soak load down meaning my fan doesn't cut in as often, and that's a fuel savings right there.

[un_yun]

(01-08-2017 )Hammerhead Wrote:  Welcome to the forum.
Fuel mileage/comparison discussions in the HH world are difficult. Trailer configurations, tire sizes, axle loads, and there are no aerodynamic equivelancies.
A freight van is a freight van. A tanker is a tanker.
We will never achieve their type of fuel mileage numbers.
A 349 excavator is not a 797 banjo is not an 857 wheel dozer, the weights are comparable. The excavator is not bad in the wind, the banjo is like a 6' diameter 30' long pipe, the 857 is like the parachutes that the military uses to drop equipment supplies. There is no way to extrapolate any reasonable comparison.
That being said, proper driving habits will maximize what you can when you can.
I run a west coast 9 axle grossing up to 190k.
My fuel mileage varies from 3-4.5, and I can some times with good conditions knock on the door of 5, but that is not the norm. When I'm empty stacked up I consistently run around 7 or higher. I'm 64-70k empty on 5 axles, and a stacked trailer is not very aero.
At 132k gross, I'm assuming you run 7axles, that's a typical range.
You should achieve 5mpg with that setup with load, wind, and terrain conditions being right, but I wouldn't expect it to be consistent.
I don't know your typical freight, but I assume it's mostly equipment that will all grab the wind differently.
I would replace the sensors that you cleaned, as the age of an 870 I wouldn't expect them to be real accurate.
Getting your injectors all working correctly will go a long way. That makes the cylinder power more consistent and the stronger ones don't have to work harder to compensate for the weaker ones.
An 870 has an air actuated VGT ipo electrical, so while they are better than a fixed vane, they aren't as good as electrical with position feedback. But there are some guys on here that are quite good at getting exceptional results.
Checking the condition of your CAC and intake tract is one if the biggest help factors. The power and economy losses here are big. Unfortunatly because of our GVW characteristics we use more torque load to climb hills and such, so this can drop off without a lot of immediate telltale signs. A 1/4-1/2mpg drop for our line of work is very easily overlooked with the common assumption that it was a little windier and this is a very realistic loss under various load conditions. This is something to not only check, but check frequently.
We can't drive like Rawze because our GVW will easily push us to too much excessive speed, but we can certainly lighten up on the fuel pedal. At 180k I'm never gonna be the first one to top of the hill, so I don't have anybody to impress, I rarely run much more than 75-80 throttle, cause I'm gonna slow down and shift anyway so why panic about it. Driving like this also keeps the heat soak load down meaning my fan doesn't cut in as often, and that's a fuel savings right there.

Thanks! I have checked all the intake piping with soapy water. Had a few leaks and fixed them. I soaped up the cac, but haven't pressure tested. I changed the delta-p and cleaned the pipes for it. I also changed exhaust back pressure switch. I will change the imap and intake temp asap. I run good boost and low egt's. I also changed all the actuators. Timing where leaking so I just did all 4. Yes I run a 7 axle, and weigh in at 45k empty. I do run a lot of the Appalachian mountains. Lifetime avg is 4.4 for this truck, which I think kinda sucks because it came from south FL. And only ran there. I have 4.33 rears and try to run about 62 to 65 at around 1600 to 1750. Again thanks for mentoring me any way you can!

[Nilao]

With 4.33 tears I think your HP at the axle is low. There are ppl with 3.55 and a single od trans with less HP losses. I'd say 15% loss at most is acceptable.

[un_yun]

Yeah, I don't really trust Cummins Atlantic, I found the bad injector just a few days after the dyno run. They told me as long as it was 20% loss or less that was acceptable. I think the hp is low too. I had hp changed before all this. And then I read how this is not so simple on an 870. So I am wondering if the file is not right even though it matches the cpl. I would like to find out how to get in touch with mr. Hag. I heard he was in atl and pretty sharp with em. I bought the truck used, and this is my first Isx. So I am not sure this isn't just in my head or not. I've not been real impressed so far.

[Unilevers]

cummins spec is 25% loss to the ground. that is right from their head office warranty and if it does that they wont do a thing and will call it acceptable.

real life losses are between 16-18% depending on the dyno, tires, driveline etc.

[Hammerhead]

(01-08-2017 )un_yun Wrote:  Thanks! I have checked all the intake piping with soapy water. Had a few leaks and fixed them. I soaped up the cac, but haven't pressure tested. I changed the delta-p and cleaned the pipes for it. I also changed exhaust back pressure switch. I will change the imap and intake temp asap. I run good boost and low egt's. I also changed all the actuators. Timing where leaking so I just did all 4. Yes I run a 7 axle, and weigh in at 45k empty. I do run a lot of the Appalachian mountains. Lifetime avg is 4.4 for this truck, which I think kinda sucks because it came from south FL. And only ran there. I have 4.33 rears and try to run about 62 to 65 at around 1600 to 1750. Again thanks for mentoring me any way you can!

Well with 4.33 rears if the previous driver(s) were like most and were running at 65 or greater that type of lifetime average doesn't surprise me. Also being a 4 axle tractor, it has also moved significant weight most of its life.

Do you have:
-A Quickserve.cummins.com account?
-An Inline datalink connector and a laptop with Insite?
If you don't have both of these, get them ASAP. The Quickserve account is free if you have less than 5 ESN's. This resource is a godsend.
You can buy a Chinese knockoff version of the cummins Inline on eBay. File sharing is not permitted on this site, but the guys here are fantastic and they will help you offsite to get it all setup. The preferred one is the Inline 5 with Insite 7.6.2
These two assets are the two most important things an ISX owner can have...next to an account on this site of course!

So let's get a detailed spec...
4.33 rears
What size tires?
What transmission?
I assume lift axle; is it dual tire full rated axle or wide base single?
List the make and model of your truck, the CPL and the software version (Calibration) that is in your engine. There are guys on here who will tell you if whoever bumped the power put the correct Cal file in.

[un_yun]

ok I'll try to answer the best I can. I do have a quickserve account. I set it up when I did my injector. I don't have a data link or insite, yet! As far as specs go, I am running 385 float tires on the steer, 315 singles on a steerable lift, and 11x24.5's on the drives. I am running and eaton 18 speed. I assume it's a double over, but haven't checked the tag. It's an international 5900. I have no idea of what version of software was put in here. cpl# is 8519.

[un_yun]

The fuel mileage I can might live with, I would like to do as good as possible. who wouldn't. The truck just seem to be weak to me, with these specs I really thought it would pull a lot better. Heck empty on a 6% 4or5 mile grade I have to get down to 15th and about 50mph before I hit the top. The other day coming up mount eagle, it was all I could do to keep up with a werner van. I can get it to pull okay if I get the tach way up to 1800. But with 4.33's I would think I could chug empty up about any hill on the east coast in the big hole.