Gauge Readings

Bob Bradford · 02-01-2007, 07:59 AM

1998.5 // 24 valve// 5.9 diesel -- Dodge 3500

I found the port for the boost gauge and installing the gauge and a pyrometer.

Now the question would be what are the normal readings for the boost and normal temp for the pyrometer. I suspect boost should be 19-20 if the wastegate moves at 19.3 but I haven't found anything to conferm it. Also I can't anything telling me what would be a critical exhaust temp for the turbo.

Any expertise would be gratfull. Thanks

75K30 · 02-01-2007, 09:37 AM

This is a very tricky question, we do not have any data on your truck to make such a call. Many factors contribute to each of these items, as well as altitude, driving style, and gear ratios, etc. etc. Anyway,your truck should be able to maintain highway speeds at approx 11- 15 pounds of boost, and with a load, or pulling a hill might see around 19 - 25 pounds, obviously, for best fuel mileage, the lower the boost, the better the mileage. Now EGT's, this is very important that you keep this below 1200 deg. This sounds kinda high, but some actually say 1300. I never like to run oil burner EGT's Any higher than 1200. Altitude will have a big effect on these as well, the higher you get, the truck will struggle to find air, and the EGT's will become higher, so be carefull in the mountains. Remember, add air to cool EGT's. Sounds wrong, but a leaner mixture, (more air) runs cooler.
Where did you mount the thermocouple for the pyrometer? Hopefully as close to the exhaust manifold as possible, and not post turbo.
EGT's can be lowered by installing a larger exhaust, and it will pick up some power too, A good exhaust can decrease temps by as much as 200 deg (sea level), and increase boost by as much as 10% at the same throttle position.
Like I said, this is avery difficult question to answer, given so many variables, but I hope it gives you a decent idea about where that Cummins should be runnin.

02-01-2007, 07:59 AM	#1
Bob Bradford Junior Member Join Date: Jan 2007 Location: Full Time RV'er Posts: 4	Gauge Readings 1998.5 // 24 valve// 5.9 diesel -- Dodge 3500 I found the port for the boost gauge and installing the gauge and a pyrometer. Now the question would be what are the normal readings for the boost and normal temp for the pyrometer. I suspect boost should be 19-20 if the wastegate moves at 19.3 but I haven't found anything to conferm it. Also I can't anything telling me what would be a critical exhaust temp for the turbo. Any expertise would be gratfull. Thanks

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02-01-2007, 09:37 AM	#2
75K30 Senior Member Join Date: Jul 2006 Posts: 2,992	This is a very tricky question, we do not have any data on your truck to make such a call. Many factors contribute to each of these items, as well as altitude, driving style, and gear ratios, etc. etc. Anyway,your truck should be able to maintain highway speeds at approx 11- 15 pounds of boost, and with a load, or pulling a hill might see around 19 - 25 pounds, obviously, for best fuel mileage, the lower the boost, the better the mileage. Now EGT's, this is very important that you keep this below 1200 deg. This sounds kinda high, but some actually say 1300. I never like to run oil burner EGT's Any higher than 1200. Altitude will have a big effect on these as well, the higher you get, the truck will struggle to find air, and the EGT's will become higher, so be carefull in the mountains. Remember, add air to cool EGT's. Sounds wrong, but a leaner mixture, (more air) runs cooler. Where did you mount the thermocouple for the pyrometer? Hopefully as close to the exhaust manifold as possible, and not post turbo. EGT's can be lowered by installing a larger exhaust, and it will pick up some power too, A good exhaust can decrease temps by as much as 200 deg (sea level), and increase boost by as much as 10% at the same throttle position. Like I said, this is avery difficult question to answer, given so many variables, but I hope it gives you a decent idea about where that Cummins should be runnin.