Cummins CAPS System Redesign

[jleamont]

I go by calculator, not computer. Miles driven divided by gallons used, that was with the gen on also (only one way up), and you have to figure we did use the AH over the weekend also. I did no calculations for the GEN or AH, just miles into gallons. I am neurotic when I drive this coach watching the boost gauge and tachometer. If I just set the cruise and let it go it will fall into the low mid 8's, I only run the cruise on flat roads with little to no wind, otherwise it throttles in such a manner that makes no sense.

[wildebill308]

On 9/12/2016 at 8:11 AM, jleamont said:

I go by calculator, not computer. Miles driven divided by gallons used, that was with the gen on also (only one way up), and you have to figure we did use the AH over the weekend also. I did no calculations for the GEN or AH, just miles into gallons. I am neurotic when I drive this coach watching the boost gauge and tachometer. If I just set the cruise and let it go it will fall into the low mid 8's, I only run the cruise on flat roads with little to no wind, otherwise it throttles in such a manner that makes no sense.

Wait till you get your EGT gage working. Low EGT= better milage.  Next question have you checked the accuracy of your speedometer? I have noticed that the computer when under the control of the cruise control will ad boost higher than I can with the throttle.

Bill

 

 

[manholt]

Ditto.  Also, on economy mode, my mpg goes down, not up...I too question the speedometer, mine reads 3 mph slower.  Found that out, when a traveling friend set his at 65 and I had to go to 68 to keep up!

[hermanmullins]

I know that my speedo. is not correct and always set my CC by the speed reading on my GPS. I rarely look at the speedo. 

Herman

[jleamont]

I am 1 mph off of my GPS and when I pass those signs with the radar on them it is accurate. I have no faith in my GPS and its accuracy, if it gets the MPH right it will be the only thing it has ever gotten right .

Economy mode is a joke, absolutely useless all it does is stop the transmission from a down shift when its needed. I may use it to see how high my EGT gauge will go , since it will wide open throttle my engine without a downshift and lug it up a hill, which is exactly what you don't want to do with a diesel engine pulling a load. I get better MPG's if I don't use cruise control or economy and pay attention to the terrain ahead.

[manholt]

Joe, my foot gets tired...I get off of CC right before a hill, up or down!   In your world, I would have a tired foot...your terrain up there is not ideally suited for CC.

Carl

[wildebill308]

3 hours ago, jleamont said:

I am 1 mph off of my GPS and when I pass those signs with the radar on them it is accurate. I have no faith in my GPS and its accuracy, if it gets the MPH right it will be the only thing it has ever gotten right .

Economy mode is a joke, absolutely useless all it does is stop the transmission from a down shift when its needed. I may use it to see how high my EGT gauge will go , since it will wide open throttle my engine without a downshift and lug it up a hill, which is exactly what you don't want to do with a diesel engine pulling a load. I get better MPG's if I don't use cruise control or economy and pay attention to the terrain ahead.

What GPS system are you using? My phone and my tablet and my Bankes IQ all have GPS and for the most part agree completely. I have run several 10 mile test and they seem to be right on the money. The banks IQ will do a correction factor for the speedometer. I have to multiply by 5.8% to get actual speed and milage. I use the speedometer on the IQ rather than my coach speedometer.

Bill

[jleamont]

Rand McNally GPS. Banks doesn't make anything for the ISL, and come to think of most of the other aftermarket companies don't either. I only have a Scan Gauge now mounted just above my camera monitor and it might give MPH as an option, not sure. When I roll through a construction zone and they have those speed limit radar signs I am always matching them, so I figured it is accurate.

[manholt]

Those construction speed indicators are very seldom calibrated.

[wildebill308]

2 hours ago, Manholt said:

Those construction speed indicators are very seldom calibrated.

On top of that the slower the speed the the smaller the deviation is.

Bill

[jleamont]

Getting ready to put the coach away for the season and I wanted to update everyone following this post on the progress.

Exhaust temp gauge is connected and I had the opportunity to run with it on our last trip along with the new toad which is heavier. It performed as I expected it to, and it climbs rapidly when you pull a hill, so it became a challenge to see what I could accomplish (yea, I sunk my foot into it a few times). I was able to hit 1100 degrees at full throttle pulling a hill, when I dropped down a gear so did the temp by around 200 degrees even with my back into it after the down shift. My average temp running down the highway was 600 degrees at cruise, 6th gear at 62 MPH. I was surprised to see how long the engine actually took to cool down to where I felt comfortable to shut it down, almost a full 10 minutes of idle before it dropped into the 300 degree range, I almost thought it wasn't going to happen. Most of this was accomplished at check in while I was getting our paperwork from the guard shack, then idle over to our site, just slightly tipping the throttle (which made it climb slightly), pull in to our site, wait for the compressor finish building air and I was under 400, but still convinced it could be cooler, so I sat for another 1-2 minutes and it dropped a little more so I shut it down.

You can really digest how an engine is performing while monitoring fuel pressure, EGT and Boost (mechanical boost gauge).

We have accumulated approximately 1200 miles on the conversion so far and it runs fantastic. Starting to plan trips for next year and getting excited.

[gglenn]

I finally read thru much of your fuel pump install, looks great.  I'll likely add an electric Dash Fuel Press. Gauge, sensor downstream of last filter and also add a pyro gauge.  Tank cooling maybe... funny thing is previous owner added a Raptor inline pump for generator at almost the the same spot as your install.  Didn't know it was there until my AirDog line routing exposed it, always thought it was the vacuum pump I was hearing.  Could easily split Raptor flow in parallel to cooler/fan and good to go.  Was actually planning on creating a parallel loop back to the tank with the Raptor for Fuel scrubber, using the Secondary Fuel filter I removed with AirDog install.  Previous owner Raptor install had no filter, just one in Gen.   Thinking would be great to circulate fuel during long periods of tank sitting, during refills, and for mixing fuel additives if I'm not driving coach soon.  Raptor is in similar tank location to your pump install, so super easy plumbing changes compared to AirDog install.

 

[desertdeals69]

On November 3, 2016 at 8:26 AM, jleamont said:

Getting ready to put the coach away for the season and I wanted to update everyone following this post on the progress.

Exhaust temp gauge is connected and I had the opportunity to run with it on our last trip along with the new toad which is heavier. It performed as I expected it to, and it climbs rapidly when you pull a hill, so it became a challenge to see what I could accomplish (yea, I sunk my foot into it a few times). I was able to hit 1100 degrees at full throttle pulling a hill, when I dropped down a gear so did the temp by around 200 degrees even with my back into it after the down shift. My average temp running down the highway was 600 degrees at cruise, 6th gear at 62 MPH. I was surprised to see how long the engine actually took to cool down to where I felt comfortable to shut it down, almost a full 10 minutes of idle before it dropped into the 300 degree range, I almost thought it wasn't going to happen. Most of this was accomplished at check in while I was getting our paperwork from the guard shack, then idle over to our site, just slightly tipping the throttle (which made it climb slightly), pull in to our site, wait for the compressor finish building air and I was under 400, but still convinced it could be cooler, so I sat for another 1-2 minutes and it dropped a little more so I shut it down.

You can really digest how an engine is performing while monitoring fuel pressure, EGT and Boost (mechanical boost gauge).

We have accumulated approximately 1200 miles on the conversion so far and it runs fantastic. Starting to plan trips for next year and getting excited.

Exactly where did you locate the egt thermocouple.  That makes a difference in the temp reading.  The last one I did it was about 2 inches after the turbo and the hottest I have seen it is about 1050.  I just completed an AirDog lift pump install on my new to me 98 Fleetwood Discovery.  As the lift pump had failed and the previous owner still drove it,  I had to change the VP44 pump also.  Drove 1900 miles last week and it ran good.

[wildebill308]

I installed mine before the turbo. I did a lot of reading and research and nearly all the instructions were for before the turbo gave more accurate readings. Some on the truck forums have one before and one after. My conclusion is you are trying to know what the temperatures are in the cylinder. I hear people worried about melting the turbo. But I bet you melt the piston tops way before you melt the high temp steel in the turbo hot side.

Bill

[jleamont]

This is the age old debate. Trucks were equipped with them for years and they were located after the turbo, drivers knew when to down shift and how long to idle down before shutting the engine off so the turbo wouldn't cook the oil off from the high temps and melt seals. Now they put them before to monitor cylinder temp like we forgot about the potential turbo failure issue.  Keep in mind you over heat a turbo and the bearings fail you could destroy the engine also when the turbine contacts the side of the housing and throws all of those fine metal shavings into the cylinders. I have seen that so many times in my career I can't even begin to remember, between that and air filters not installed correctly.

I felt I idle long enough when I arrive so the manifold made sense plus I was checking mine with the heat gun comparing the turbo temp vs manifold temp, even at 400 in the manifold I am well below the safety zone to shut it down at the turbo, there is a 100 degree difference.

[jleamont]

Obedb, THIS is the thread on redesigning/upgrading the CAPS system.

This is the "last post", so it on the third page of posts. Probably reads best if you start on page 1.

[jleamont]

I moved some stuff around for better use of the space on hand. I also positioned the mechanical gauge so I can see it through the right side fuel door without having to open the big door.

 

[jleamont]

Old positioning 

[dickandlois]

Joe, Do you keep a soft blow hammer in the bay to start the fuel pump? LOl

   just could not pass it up! 

Did you forget to connect the water in fuel connection? or is it no longer in use?

Rich. 

[jleamont]

Rich, my secondary filter has the water sensor to the dash light. Figured there was no reason to have 2. The other connection is a heater, no need for that either. 

LOL, on the hammer .