6.7 cummins maxing out egts towing 4k pounds?

[The motor guy]

I don't know if it's the trailer or what. Maybe a brake is dragging, but it feels like i'm pulling a train even when the trailer is empty. It easily sustains 1000-1100 egt temps and if I try and run 65-70mph.

 

[mattd]

I don't know if it's the trailer or what. Maybe a brake is dragging, but it feels like i'm pulling a train even when the trailer is empty. It easily sustains 1000-1100 egt temps and if I try and run 65-70mph.

what are your egts unloaded? Where do you have your probe?

 

[The motor guy]

The probe is in the manifold pre turbo. Egts unloaded doing 70mph are like 650 degrees.

 

[mattd]

What are your boost/backpressure numbers when towing? Any smoke out the tailpipe when towing? It is very possible you could have a brake hanging up on the trailer.

650 unloaded is just right

 

[wwillson]

It easily sustains 1000-1100 egt temps

Those temps would be high post turbo, but I don't think they are high at all pre turbo. A dyno run at Banks on a stock Duramax showed 300-400 degrees Fahrenheit drop across the turbo. If I remember correctly, the stock Duramax pre turbo is EGT limit is 1350F sustained and 1425F peak.

 

[The motor guy]

The boost Guage is inaccurate, but it's usually like 5-7 psi. I don't have a drive pressure gage. The boost gage works it just doesn't zero out.

 

[wwillson]

but it feels like i'm pulling a train even when the trailer is empty.

What type of trailer? Enclosed trailers with flat fronts pull like a brick, as they have a ton of flat-plane drag.

 

[Rand]

we need details could you post all the missing stuff.

one line isnt enough to get a good answer.

Type of trailer,Trailer weight? how many axles? shape/design?
terrain, outside temp. etc. should have all been in the first post.

We dont even know your location or anything.. so.....
Is truck stock?
question with no details = generic or inaccurate answer at best.

 

[mattd]

Those temps would be high post turbo, but I don't think they are high at all pre turbo. A dyno run at Banks on a stock Duramax showed 300-400 degrees Fahrenheit drop across the turbo. If I remember correctly, the stock Duramax pre turbo is EGT limit is 1350F sustained and 1425F peak.

A general rule of thumb is 1250 * sustained temps is The limit. 1100* is high for that light of a trailer IMO.

OP, need more data to better help you. Do you know anyone with diagnostic equipment?

 

[wpod]

Are you lugging the engine?

 

[The motor guy]

It's a 16ft trailer expanded metal sides.

Are you lugging the engine?

It stays around 1500-2000rpm