How long, generally, is a break-in period?

It’s not going to hurt anything other than fuel economy.

 

I know it's just odd. It says it makes all it's torque at 1150 but the second it falls under 1400 it's dead and youre grabbing 2 gears to make up for it

 

My Detroit is the same way. I had a egr Isx it was a slug unless it was at 16 or 1700. The Detroit is better but still needs to be over 1450

 

I ran a 485 Paccar before this cummins and it would run down to 1100 and still be pulling, but over 15 it was useless. I think I just got used to driving that way

 

Figure 70mph at 1400 would be 3.36 gears.

Cummins like 1500 and above rpms for longer life.

You should be getting at least 30 psi of boost under full throttle.

Run it and see if it gets better.

 

I'll give it some time. I definitely don't get 30 psi even running it hard on a long pull

 

It's under warranty. Have you spoke to the dealer? Tell them you think the fuel pressure is low causing it to lag in power at the low end and limiting you boost at the upper end. What kind of turbo boost are you getting?
Check your, Air-to-Air isn't leaking too. Do you hear a whooshing noise when you stomp on the accelerator?

 

It's a company truck, way out of my hands lol and I do not hear a whooshing noise, just the normal air flow sound from the air cleaners. If my old truck didn't have so many miles on it I'd ask for it back

 

Thats how u got to run these cummins. I run at 1400-1500 all day long . Pull hills at 1700... just keep er up in that range. Especially with a flatbed hauling 80k all the time.ur gonna want ur rpms up higher and she will power thru the hills.

 

I don’t know about Cummins, but Detroit usually is fully broke in around 70k.