2006 CX613 AC 460p ASET 460- How to boost power/MPG?

[mercury]

This tractor pulls 50,000# garbage to landfill, 470 miles return. Fuel economy is not great, and driver complains that he has to drop gears to get up hills, it doesn't seem to have power.

Specs on truck

- Engine AC460P -ASET 460 hp- TRANSMISSION - 18 SP FULLER - RTL-016918B- Rear axle - RT46-164EH - 4.10- Suspension - AL461 60" SPACING- Front tire size - 12R22.5 , 484 revs per mile-  rear tire size - 11R22.5, 495 revs per mile- top gear ratio - .73 ratio

It has 168,000 miles, and 8700 hours. Lots of hours to pack garbage in compacting trailer with wetline . Recent new EGR, manifold bolts, injectors, turbo, and reflash by Mack dealer. Doesn't make a big difference.

We just can't believe this truck can't do better. We think it's just short on enough power, and would love to get better economy. I am asking the forum, what experience do they have with these tractors, how to boost them up, and what kind of fuel economy should we expect? Any thoughts would be appreciated.

Thanks Mercury

[slpwlker]

First question what is he grossing? Also how fast is the truck going? Idle time will play a part but if they are home everynight there is no idle time when not dumping. No matter what you get even with a 600 and that gearing you'll drop a gear usually. What kind of mileage are you getting? Also may want to run a hard roll tarp to cover the top or if you have a dual open tailgate open the center to reduce drag. I can tell you from experience with that gearing you can get mileage or decent mileage but it is a work in progress. Also I know more about Cat Vs Mack and they have there own sweet spot. What kind of boost is it running? HAs it gone down any?

Oh yeah welcome to the jungle

[lucerne tractor]

pressure test the charge air cooler, that will kill your power,if leaking, they are known to crack, it will make boost slow and surging,make poor fuel milage.any codes?

[rsb502]

sounds like a typical ASET engine, Mack changed the rear wheel horsepower requirements when they went from the ETECH to the ASET the ASET 460P or 487hp doesnt make the same hp as the ETECH 460xt (487hp) its actually allowed to rear wheel 68% and be considered good ( ithink it was 68) I cant remember but it was like 12% less than the ETECH. There are ways to make power, retuning the ecm will do a ton its just screwed by the emisions and its all in the ECM tuning if it was set free it would run great but instead they are cut wayy back to meet emissions requirments. Illinois dyno center will reflash your ecm for power I think there are a couple others now too. Oh and with an 18 spd and 4.10 rears on 11R22.5's I would think it would pull great but I dont know what kind of hills your pulling, obviously due to torque multiplication you would downshift to 8th low to be in direct to get the best rear wheel hp, go into OD and you lose torque to the wheels fast a 3.90 might seem to pull better just because you get more speed in direct, how far is your driver dropping gears before it pulls the hill? If it pulls in direct its making enough power for the load you just need to get the driver to realise thats what its geared for. A 4.10 on the interstate isnt that great you would have to drop down to about 47 mph to be at 1600rpm with a 41" tall 11r22.5 in direct which is pretty slow a 3.36 puts you at 60 at the same rpm. I obviously dont know what about the truck your driver is complaining about I had one tell me one of my trucks wouldnt pull right once and I got in it and it did great in direct gear in the power band of the engine about1600rpm, i took a ride with him and he had it wound up in OD and when he had to drop to direct and the rpm pulled back to about 1600 he said it wasnt pulling right and we had to have a talk about what I have typed above, after that he tried hitting some hills in direct from 1500-1700 rpm and he said he never had to drop a gear. I suggest taking this into consideration and driving it yourself thinking about what gear you are in and what rpm your running, too many rpm and it will drop back to where it makes torque to few and you will have to drop a gear to get up into the torque, and as always OD wont pull as well as direct thats whay a lot of truck used to be made with direct trans and 3.36 and 3.55 gears they made more rear wheel toque than an OD trans and lower gears making the same rpm at the same speed.

[rsb502]

THE ABOVE INFORMATION IS ALL PURE SPECULATION ACCORDING TO A FRIEND HERE! OH OK HE SAYS ITS PURE B.S. NOW!

[Challenger]

Have you checked the fuel and boost pressures?

[Mackpro]

Replace the boost pressure relief valve on top of the intake manifold elbow if it hasn't already. Have the complete intake manifold, piping and after cooler pressure checked. Get the "Step 12B program ( throttle responce program) installed at a dealer. Get the valves adjusted and replace the rocker arm hold down bolts with the newest part# ( could save u a $4000 cam job). If single exhaust replaced the muffler, at work I have the Walker or Donnelson part #(cant remember which brand) of a good cheap high flow factory fit muffler that is quiet but flows alot better than the factory. We have had good luck with it in MPG in some over ther road trucks. I'll post it tomorrow. Run a clean air filter and make sure the hole in the hood matches the hole in the air filter housing, make sure the rubber boot is on the opening on the air cleaner housing. If equipped with a fuel heater or a Davco fuel filter with built in fuel heater, install coolant shutoff valves and keep them shut off till near freezing. We have seen good MPG gains in the summer by not super heating the fuel. Mack now puts 10/30w motor oil in all their MP engine due to MPG gains but I dont know if I would change unless a total rebuild or reman engine just installed. The muffler I was talking about is a Walker part# 2191-m100436. It's the exact same size as the orignal and will bolt right on.

[mercury]

Thank you for your input to date. Some more info to "percolate " on.<br /><br />Truck runs at 65 miles per hour ( governed) @1650rpm, 35 psi boost, and 90 psi in fuel rail.<br /><br />GVW is 55,000kg (120,000#) , Tare weight is 29500kg ((65000#)<br /><br />EGR cooler was blocked, repaired and EGR replaced, valves and rocker arm bolts - 1 year ago<br /><br />Turbo replaced, manifold bolts replaced, 4 new stock injectors, new lift pump - 4 months ago.<br /><br />Fuel economy from previous calculations, which I do not trust, was 4.5miles /US gallon. Working on getting some good data.<br /><br />Remember, the truck is loaded to destination, then empty on return, so fuel economy is an average. 235 miles each way<br /><br />We are intent on getting the best out of this unit, as we have 2 years to go. We appreciate all your comments and would love to hear about your thoughts for improvement, and also what mileage we should expect with a load like this. Would like to hear what other similar rigs / different tractors get for fuel economy<br /><br />Thanks Mercury

[Mackpro]

Your about right on the RPM's as Mack recomends 1600 RPM cruise speed for the AC 350, 400 ,427 and 460 ( P and E models). The AC 330/350 and 355/380's recomend 1500 RPM. The 120,000 LBS,s might be the killer, our coal hauling guys down here that haul that weight get about the same MPG as you, They bought some CHU's with MP-8's and the 100 extra cubic inches helped their MPG by almost a full mile per gallon if not more in some cases.

[slpwlker]

What kind of tires are you running on the trailer and truck. I have been running a 4 of these on my trailer. 4 axle lowboy. with just 4 of these I noticed an increase however slight it was but an increase in my economy. Now multiply that by 3 more axles which I had not done at the time I should gain a very noticeable increase. Might try these on your trailer and if you do not lug tires on the tractor to and you should notice a big saving.

http://www.michelintruck.com/michelintruck/tires-retreads/tireInfo.do?tread=XZA2%20ENERGY

The weight will hurt but it can be gained. I gross between 132k and 160k average between 4 to 7 mpg loaded and empty. best loaded is 6 flat

[rsb502]

Thank you for your input to date. Some more info to "percolate " on.<br /><br />Truck runs at 65 miles per hour ( governed) @1650rpm, 35 psi boost, and 90 psi in fuel rail.<br /><br />GVW is 55,000kg (120,000#) , Tare weight is 29500kg ((65000#)<br /><br />EGR cooler was blocked, repaired and EGR replaced, valves and rocker arm bolts - 1 year ago<br /><br />Turbo replaced, manifold bolts replaced, 4 new stock injectors, new lift pump - 4 months ago.<br /><br />Fuel economy from previous calculations, which I do not trust, was 4.5miles /US gallon. Working on getting some good data.<br /><br />Remember, the truck is loaded to destination, then empty on return, so fuel economy is an average. 235 miles each way<br /><br />We are intent on getting the best out of this unit, as we have 2 years to go. We appreciate all your comments and would love to hear about your thoughts for improvement, and also what mileage we should expect with a load like this. Would like to hear what other similar rigs / different tractors get for fuel economy<br /><br />Thanks Mercury

Well at 120,000 mileage wont be great and you have to realize this is a 12 liter engine not a 14-15 liter, so a Cummins ISX, CAT C-15,Detroit 14/15 liter are going to pull that weight better, they will make more torque and the larger displacement means more rotating mass to keep the rpm and torque up. I gotta say again 65mph is in OD, and you have to drop back to direct to get the torque multiplication you need to haul that much weight, if you hit a good hill i would bet it drops down to direct and holds and if you hit the hill in direct at 16-1700rpm you wouldnt have to drop a gear and it would pull right up its just physics. I dont think the mileage is that far off either I got 6.7 in My Granite triaxle with a 427 ASET running 74000 with not much idle time, you stated your truck gets a lot of pto hours so you have to figure your numbers are going to be about 1.5 to 2 mpg off from a truck that doesnt run the pto like you are so add the 2 mpg back to your 4.5 and you get 6.5 if the truck is a daycab you also have to deal with the aerodynamics of pulling a tall flat fronted trailer at 65mph which arent good with a daycab. You can reflash the ecm for more power but I would bet yours is right in specs from what im reading, I have heard of 460p engines making some big rwhp numbers with flashed ecm's but the egr needs to be blocked off or removed and the ecm calibrated for that also or it will clog with the extra fuel and soot.

[Artur Bulat]

i am new to the topic , but i have a question if anybody knows where i can find that part. its part of the turbocharger for ac460p mack engine 2003

[felicello122]

Try D &W diesel in Albany,N.Y. L got the actuator for a cat there. That opens and closes the waste gate.

[Mackpro]

Mack part # 7536-173935 and there about $1200. And thats just the actuator not the whole turbo, crazy I know.

[felicello122]

You can get that part at D &W for around 100 bucks, it looks just like the one on the cat.

[James5]

I have a 10 speed automatic 2006 Mack vision and it doesn’t seem like I’m getting much power I push the gas paddle to the floor and it seems like it struggles to get to high speeds and want give me more then 70/80 mph is there anything I can do to speed it up or correct it if it’s a issue