1993 DT360 Turbo Question

onenationundergoat · 08-05-2015, 05:56 PM

I have a DT360 and it seems like it's not getting all the power it should. I have to rev it up quite a bit to get it up over a 3" or less edge to put it in the hangar. It has a turbo but doesn't make that "jet engine" whine noise. How can I test it and see if the turbo is working/has a problem?

Would adding an aftercooler help give a power boost? I've also heard it increases mpg.

Another theory is that maybe the fuel uptake filter is clogged (if it even has one?), as I've noticed some people mentioning that on here and saying it was starving the engine of fuel.

nat_ster · 08-05-2015, 06:00 PM

Install a boost gauge if the turbo is in question and report back.

Check all the rubber boots in the intake piping to make sure your not leaking out all the turbo boost.

Is it real hot weather?

Do you have a auto or a manual trans?

How long have you owned the bus?

Is this something that just started?

Nat

onenationundergoat · 08-05-2015, 06:42 PM

It's been real hot here. We bought the bus a few months ago but haven't had it on the road since we brought it home other than the surrounding mile of country roads by my house. It's an auto trans.

crazycal · 08-05-2015, 06:48 PM

It's your transmission. You probably have an AT545 that's tired. I once backed the back wheels off the asphalt. We are talking 6 inches. I was afraid I would need to call a tow truck to get me back onto the asphalt.

HolyBus · 08-05-2015, 09:27 PM

I have the same combo here.I move away a few feet from the curb and get a rolling start that way.

claydbal · 08-06-2015, 06:35 AM

check the prefilter for blockage. its not uncommon to hear th motor rev when taking off from a stop. you wont hear the turbo unless you remove the air filter. why would anyone have a curb in front of a hangar?

onenationundergoat · 08-06-2015, 07:23 AM

It's not a curb, it's just that there's grass until the concrete pad, which is about 3" thick. The sliding doors sit against it on the outside so the ground is lower than the concrete. A foot away from the edge the ground is about even with it, but I guess it's dug out there for the doors. The planes and boats stay in another part that is gravel so they won't have that to bounce over.

It's just odd to me that I'd have to push the pedal halfway down to get over that.

Scooternj · 08-06-2015, 08:31 AM

Quote:

Originally Posted by onenationundergoat

It's just odd to me that I'd have to push the pedal halfway down to get over that.

I've done that with ambulances and tactical vehicles to get them up over the curb. Remember, you have a round object trying to go up over a square/rectangular object.

EastCoastCB · 08-06-2015, 08:40 AM

I have to push my pedal down a good ways just to get moving on grass or dirt. I wouldn't fret too much.

Tango · 08-06-2015, 09:18 AM

"Would adding an aftercooler help give a power boost? I've also heard it increases mpg."

You will get more effect from an air-to-air "intercooler" than an "aftercooler" though either will help.

On my 4BT the intercooler factor is about 10-12% on HP and close to the same on mpg. Cooler, denser intake air makes a very big difference in performance on any internal combustion engine.

I was just going over this topic myself with a 25+ year Cummins tech while working on the design for a new CAC for my motor.

Booyah45828 · 08-06-2015, 09:43 AM

Quote:

Originally Posted by onenationundergoat

I have a DT360 and it seems like it's not getting all the power it should. I have to rev it up quite a bit to get it up over a 3" or less edge to put it in the hangar. It has a turbo but doesn't make that "jet engine" whine noise. How can I test it and see if the turbo is working/has a problem?

Would adding an aftercooler help give a power boost? I've also heard it increases mpg.

Another theory is that maybe the fuel uptake filter is clogged (if it even has one?), as I've noticed some people mentioning that on here and saying it was starving the engine of fuel.

You don't need HP to get over the ledge, you need torque. Check your transmission to make sure it's in 1st gear and that the filters aren't plugged. A worn/loose torque converter could cause this as well.

In my experience, every dt360 never makes the high pitched squeal from a turbo lighting off (jet engine noise). I don't know if it's by design or something was wrong, but they're all quiet compared to modern vehicles with vgt/wastegates, which are used to shorten the time it takes to light the turbo.

An intercooler/aftercooler will only cool the incoming air. Which will only increase efficiency slightly. In order to make more power, you'll have to add more fuel.

Are you down on power on the highway? That is when you'll notice plugged fuel filters.

To be honest, I think you're just experiencing the nature of the at545. The stall speed of the torque converter is intentionally high on that trans which will create the effect your describing.

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