NHC 250 5 Ton performance

[CMSGT]

I brought my 5 ton down from the mountains today, through Wy on my way to Utah. On the highway, going up hills my truck will not maintain good speed. I had to drop to 3rd at one point and was doing about 25. Is this normal? With all the low gears/power I thought Id be able to maintain 50 going up the hills but I cant. Any info is appreciated.

 

[Gamagoat1]

Very Normal.
Not much horsepower to weight ratio.,especialy on the M816........
Mine does the same here in Colorado at around 7ooo ft where I live.

 

[drgreg]

I don't loose that much speed and seldom have to downshift, never into 3rd.

 

[dm22630]

Your giant tires are not helping.

 

[Gamagoat1]

Hey DRGREG,
What altitude are you?
He's up here in the rare atmosphere where you have to add oxygene to get it to run like out on the coast. But your'e right , the tires look neat but don't help when there is so little HP available.

 

[bigelk50]

I would say if you had the 1100s on it you might rarely shift into fourth. Around here I can pull every gear in fifth except one in my 5 ton.

 

[DaveP]

I have crawled up many grades in 3rd gear with my 5 tonners.

I was grossing nearly 80,000 pounds monday with my M819 & M270.

not a fast ride untill it got wound up on the flats.

then whenever it thought it spotted a uphill grade the speed was dropping.

using the t case works a little better if you dont mind dropping into low range.

it would be best if this move was practiced on flat ground while empty just so

you get the hang of it.

just my opinon.

 

[bigelk50]

I was guessing that you were talking about your truck being empty?

 

[Hammer]

Don't shift to 3rd gear in high, shift into low 5th gear. In my truck, with the 16.00 tires, I have to drop gears on the hills in southern OR/CA. 5th gear low range will maintain a few more mph then high range 3rd gear. Which really makes all the other trucks around you a LOT happier....

 

[Kjb2007]

DaveP do you have a pic of your truck/trailer combo setup attached? Be interesting to see

 

[CMSGT]

Yes the truck was empty, I think the altutude there is around 8k so Im sure that has allot to do with it, plus the hills I am talking about are about 3.5 miles down then 1 mile flat then 3.5 miles up. It even drops my powerstroke when pulling but I just thought going into 3rd empty was excessive.

 

[dk8019]

I have a hill near my house. There's a light at the bottom, and I would say it's a 6-7% grade. If I have to start from a stop in the M814, I won't be able to shift out of 3rd until I finish the hill. The change between 3rd and 4th for me are just too great.

 

[DaveP]

heres a couple.

I will have to try to find more.

 

[jwaller]

Yes the truck was empty, I think the altutude there is around 8k so Im sure that has allot to do with it, plus the hills I am talking about are about 3.5 miles down then 1 mile flat then 3.5 miles up. It even drops my powerstroke when pulling but I just thought going into 3rd empty was excessive.

with those tires I say get used to it. do you emit black smoke from the stack? is your 250 running in top shape? have to changed fuel filters, adjusted the valves?

might be time to start thinking about a turbo if you are that annoyed about it. I was and I had to add a turbo to make up for the lost power.

 

[CMSGT]

with those tires I say get used to it. do you emit black smoke from the stack? is your 250 running in top shape? have to changed fuel filters, adjusted the valves?

might be time to start thinking about a turbo if you are that annoyed about it. I was and I had to add a turbo to make up for the lost power.

Theres no black smoke, it seems to be running OK, Im doing all the filters now since I got it back down from the mountains. The tires definately make for an interesting road ride! I only drive it on the road for the trip in and out of the mountains for spring/fall or getting large supplies to take in the mountains. Im sure I can deal with it for a while. How much of a difference did the turbo make? Was it a difficult job?

 

[mahdey]

naturally aspirated diesel, what do you expect? With the elevation you were at there is not enough oxygen for your engine or any NA engine for that matter to run efficiently. Turbo induction usually solves the problem. Fourwheeler has a very nice article where they put the banks sidewinder kit on 6.2 blazer and the performance was night and day. About a month ago pulling 10k with my dodge with the cummins, i blew an inter cooler boot. Basically i was running NA and it was a DOG. I couldn't maintain 35mph up the hills and i was only at 3k feet.

Conclusion: Turbo charge your truck.

 

[73m819]

my 819 with stock 1200s does not like long hills, at times droped into 3rd, the problem is the crap trans, a 4 speed with od., the hole between 3rd and forth is so bad , you are over tacking or luging. a 8 or ten speed or a aux. box behind the xcase would make a lot better road driving truck

 

[jwaller]

my 819 with stock 1200s does not like long hills, at times droped into 3rd, the problem is the crap trans, a 4 speed with od., the hole between 3rd and forth is so bad , you are over tacking or luging. a 8 or ten speed or a aux. box behind the xcase would make a lot better road driving truck

roger that. I wind 3rd to redline and put it into 4th and suddenly I'm back at idle rpms. I hate that hole more than anything.

 

[jwaller]

Theres no black smoke, it seems to be running OK, Im doing all the filters now since I got it back down from the mountains. The tires definately make for an interesting road ride! I only drive it on the road for the trip in and out of the mountains for spring/fall or getting large supplies to take in the mountains. Im sure I can deal with it for a while. How much of a difference did the turbo make? Was it a difficult job?

you should be seeing some smoke. maybe a new fuel filter will fix it. it usually did for me.

turbo is easy. total cost was about $400 and the differance is night and day. I can now pull my 49' trailer loaded with 1600 tires like yours and mantain my 65mph on most any hill. last haul I grossed 70,000lbs. Not really a lot of load bc my truck weight 23k and trailer is 18,500.

 

[OPCOM]

What is the reasonable EGT and boost limit on the NHC-250?