ISX450.......unrealistic expectations?

[Golfnut]

About three weeks ago I purchased a 2014 Kenworth T680 with an ISX450/1650, 10 speed manual transmission and 3.55 rear end. It has 326,000 miles. I was coming from a Freightshaker with a C12 at 410/1250 with a 10 speed and 3.42 rear end. I'm a farmer and regularly haul 80-85000lb loads and was expecting to be able to comfortably run up and down the highway at 70 mph. After I got it home I had the local dealership (Freighliner/Cummins shop) remove the 63mph speed limiter, progressive shift, and gear down. When I get on the highway, which is mostly flat, I have a hard time getting past 63-65 mph when loaded. If feels like in 10th gear it just falls flat on its face. It has new air and fuel filters (restriction gauge stays very low for both)

Out of frustration I took the truck to a private, well respected shop hoping they'd find something the other shop missed. I just heard back from them and they indicate everything is ok and that I really and short on power and especially torque for what I'm wanting. They say they can up the torque to 1750 but not HP unless I delete emissions, which at this point I'm not interested in doing.

So, do I have unrealistic expectations or do I need to dig deeper? I can post pictures of the engine data plate if it will be helpful.

[Nilao]

It can be tuned with emissions. Just takes a special hand. Also alot of shops wouldn't know what they're looking for if Rawze gave them a guide...oh wait, he did..it's rawze.com

[Soulreaver0102]

I’d say read through forum and get with one of the guys that does tuning listed on this site. They’ll help you out.

[Golfnut]

I have spent a lot of time reading through the forums and suspected that someone would suggest I do an EGR tuneup. When I get the truck home I plan and taking a look at that. If a new tune would help me and be safe I'd consider that as well. Do you have any recommendations of shops in Central Nebraska that are qualified?

[Chamberpains]

Oh boy, you need to get an education from this site. Everything your stating sounds like the exact mentality that will leave you and your equipment in poor condition.

60-63 mph is a terrific speed to run. Good mpg's, less stress on you and the truck, no speeding tickets, not always stressing to get around guys. It's just a good profitable trucking speed.

Get rid of that BS gotta hammer hard mentality. Less is more. You won't get there much faster by hammering at 70mph than you will at 60mph. And you'll have to run a lot more loads to just make up for all the profits you're blowing out the stack and dumping back in the truck on repairs. It's a vicious cycle that never pays off. If you want to get there faster, then concentrate on loading quicker and not stopping the truck once you get rolling. It's all the other things that you do in trucking that makes the real difference in how fast your load gets moved. Not driving faster.

I run a truck with 450hp and 3:55 rears and have zero problems pulling 80000+ lbs up and down mountains. But I'm also not in a race ever. I want to keep the money I'm getting paid. Not be the 1st one up hills or leading to pack.

Next up is your reliance on shop (especially dealershits) You need to get a laptop and Cummins Insite so that you can carry and use the exact same program the stealershits used to rape you of your hard earned $$. Knowledge is power and big $$ in this business. Doing your own repairs will ensure they're done to your standards and done correctly. Plus this site is here to help if you run into problems. Learn how to diagnose those pesky emissions and engine problems. There is huge $$ in it.

Next up, if you want more HP or torque, there are very few guys that get recommended from this site because there are very few that can do it right. Don't believe me? Then read a few from here and there are many many more. http://rawze.com/forums/forumdisplay.php?fid=73

If you want good tuning, PM Unilevers or mommaburt, call mr hagg or gearheads shop. They'll get you fixed up. They'll set it up to whatever hp and torque you want. Anyone else that says they can't you should run away from. THEY DON'T KNOW WHAT THEY ARE DOING!

Even as a farm operation this advice will turn a good long term profitable operation. You won't constantly be working on hammered out equipment. You can spend the extra time growing other things.

[Golfnut]

Chamberpains.....I appreciate your honesty and your right on some things and wrong on some others. I've maybe made it sound like I want to run fast all the time. That is not true as the majority of my hauls will be short hauls to the elevator and back. My concern is that my truck flat out acts like it does not have the ability to go any faster than 63-65 on flat ground. Zero top end power. I don't want to be stuck at 63 mph because that's all I've got. I'll be getting poor mileage regardless of my tune because my trips will include too many turns and stops. An average run to the elevator for me is 8 miles with three stops/turns plus one railroad crossing.

For the record, I'm not looking to run 550/2250. I realize that would be overkill. I'm sure there are a few of those around but not many. I'm just trying to learn what I've got./

[Magard]

A 450/1650 is not the problem. That’s plenty of power for a flatland farmer truck. Get some gauges on it. Helps diagnose problems. Egr tune up and charge cooler leaks is probably the place to start. Even if you don’t pull the intake manifold at least get all the sensors done and see if it helps. No one will want to do any remote tune work until you get it right anyway. It’s to frustrating to figure out a basket case remotely. Also if sensors don’t help I would be looking at a egr valve being possibly partially stuck open. Those are just a few simple places to start.

[tree98]

I'll bet you the dealer didn't turn off your speed limiter even though they say they did. They are morons.

[Chamberpains]

You may also be dealing with a fully restricted exhaust. Try pulling the exhaust pipe off at the turbo and take it for a spin to see if your power comes back.