Boost Gauge readings

[Dave Shackelford]

I have a 2005 ISL400 Camelot40pdq. My boost gauge reads a range is 5 to 15 lbs while driving on level roads. It does go up a little when I get into the mountains. My question is this a normal reading for my rig ?

thanks,

Dave

[Craggar]

Sounds low to me.

[Scotty Hutto]

My 06 Dip has a 2005 ISL400 also.  My boost readings vary from 0-27psi. Normal level road driving is around 5-15 psi.  

[Dave Shackelford]

37 minutes ago, Scotty Hutto said:

My 06 Dip has a 2005 ISL400 also.  My boost readings vary from 0-27psi. Normal level road driving is around 5-15 psi.  

Many thanks,

Dave

[Craggar]

4 hours ago, Dave Shackelford said:

I have a 2005 ISL400 Camelot40pdq. My boost gauge reads a range is 5 to 15 lbs while driving on level roads. It does go up a little when I get into the mountains. My question is this a normal reading for my rig ?

thanks,

Dave

Guess I misread the question but when you say it goes up a little in the mountains, it should go up a fair bit on the hills.

[TomV48]

My 2005 Ambassador, rear radiator 8.3 rated at 330 HP seems to hang up at max 22-23 with my foot in it and "appropriate" rpm.  Seems like it used to give me more.  Thinking I need to get a Cummins shop to plug it in and check my diagnostics.  Am I thinking right or expecting too much?

[96 EVO]

Flat road, 62mph in 6th gear, no wind, I'm hovering about 8psi boost.

[Ivan K]

Nothing wrong with having diagnostics done by a trustworthy diesel shop but first I would check for obvious air leaks around the turbo coupler hoses, that should be easily doable and fixable. Just like the air filter check. Different engine but my boost gauge goes all the way to 30 before the needle starts shaking when the blow off activates. I try to stay below it. Kinda glad I don't have vgt for maintenance reasons, that could be an other cause of low boost when malfunctioning. 

[zmotorsports]

Similar with our 2002 year ISL400, flat highway 65~ish mine reads around 8-9 PSI.  Climbs to 29 when working her on the grades but I've played with the boost pressures to get my EGT's down a bit.  Originally, it would only generate about 23 PSI of boost pressure, but the 5-15 at cruising speeds is pretty accurate. 

[Rikadoo]

My 2003 HR cummins will when approaching hills momintarily read full boost “30 psi” then it pulls back an long pulls drop to less somewhere 26 ish. At 1st thought a leak untill one time watching the EGT and at the time it was very close to 1200 degrees and over 30 psi m it dropped to 1100 ish instantly with psi now 26 psi. I had rembered that when i bought the new to me coach it already had a Banks Stinger kit installed on it. And reading the info on the stinger thats its main task in that it monitors the EGT temps when giving you full power and if the temps get to high it changes the fuel rate to reduce the temps which in turn lowers the psi. Its gotten so automatic for me i almost never pay attention to the gauge anymore.

[timaz996]

18 hours ago, Dave Shackelford said:

I have a 2005 ISL400 Camelot40pdq. My boost gauge reads a range is 5 to 15 lbs while driving on level roads. It does go up a little when I get into the mountains. My question is this a normal reading for my rig ?

thanks,

Dave

Like Mike and many others here, we also have a EGT gage. It can save your engine. If you have low boost and high EGT you most likely have a boost leak. Not good.

[bborc2005]

tomv48 your boost is about right, I have a 2007 Knight with the same 8.3 and the most I have ever seen is 24lbs

[Dave Shackelford]

Many thanks for all the info.

Dave

[TomV48]

4 hours ago, bborc2005 said:

tomv48 your boost is about right, I have a 2007 Knight with the same 8.3 and the most I have ever seen is 24lbs

Thank you ROBERT.   Love this group.   Seems less alone out here with you guys available to back us up.

8 hours ago, Rikadoo said:

My 2003 HR cummins will when approaching hills momintarily read full boost “30 psi” then it pulls back an long pulls drop to less somewhere 26 ish. At 1st thought a leak untill one time watching the EGT and at the time it was very close to 1200 degrees and over 30 psi m it dropped to 1100 ish instantly with psi now 26 psi. I had rembered that when i bought the new to me coach it already had a Banks Stinger kit installed on it. And reading the info on the stinger thats its main task in that it monitors the EGT temps when giving you full power and if the temps get to high it changes the fuel rate to reduce the temps which in turn lowers the psi. Its gotten so automatic for me i almost never pay attention to the gauge anymore.

Thank you.   Reminds me that before hot weather, I need to get EGT displaying on my ScanGaugeD

[cbr046]

7 hours ago, TomV48 said:

Reminds me that before hot weather, I need to get EGT displaying on my ScanGaugeD

Make a post or drop me a PM if you get EGT showing on your ScanGaugeD.  EGT doesn't show up in their standard 15 command set, but according to their website more commands are available through their X-Guage commands.  I'd like to verify EGT availability before I jump into a purchase.  https://www.scangauge.com/products/scangauge-d/

- bob

[VinceB]

On 2/12/2024 at 9:20 AM, Rikadoo said:

My 2003 HR cummins will when approaching hills momintarily read full boost “30 psi” then it pulls back an long pulls drop to less somewhere 26 ish. At 1st thought a leak untill one time watching the EGT and at the time it was very close to 1200 degrees and over 30 psi m it dropped to 1100 ish instantly with psi now 26 psi. I had rembered that when i bought the new to me coach it already had a Banks Stinger kit installed on it. And reading the info on the stinger thats its main task in that it monitors the EGT temps when giving you full power and if the temps get to high it changes the fuel rate to reduce the temps which in turn lowers the psi. Its gotten so automatic for me i almost never pay attention to the gauge anymore.

I have the same kit on my 330 ISC.  It will hit 32 psi and let the EGT climb to around 1250 and adjust the boost to keep it below 1250-1300. Generally I climb hills at 30 and 1250.  My biggest problem is out pulling the truckers and having to go around them.

Once I saw it only go up to 27 but 1300 and thought there was a boost leak - sure enough there was.

Another issue for low PSI and high EGT was the exhaust brake was not opening all the way (partially sticking closed) - had it replaced -problem solved.

[zmotorsports]

1 hour ago, VinceB said:

I have the same kit on my 330 ISC.  It will hit 32 psi and let the EGT climb to around 1250 and adjust the boost to keep it below 1250-1300. Generally I climb hills at 30 and 1250.  My biggest problem is out pulling the truckers and having to go around them.

Once I saw it only go up to 27 but 1300 and thought there was a boost leak - sure enough there was.

Another issue for low PSI and high EGT was the exhaust brake was not opening all the way (partially sticking closed) - had it replaced -problem solved.

 

Yeah, that old Banks Powerpack kit really turned some of these rigs into hot rods.  Bumps the power output to 430hp/1200+ lb/ft of torque.   I put one on my cousin's 36' 2000 Country Coach Allure with the Cummins ISC about 15 or so years ago when they were available, and it totally transformed his coach.  Kind of sorry I did that afterwards as it made it nearly impossible to keep up with him.   Granted his coach is only 36' with one slide and towed a 20' enclosed trailer weighing around 8k loaded and with our 40' Dynasty we were towing a 13k pound 26' enclosed trailer, but still, it was hard to run with him up the grades.  

[VinceB]

8 hours ago, zmotorsports said:

 

Yeah, that old Banks Powerpack kit really turned some of these rigs into hot rods.  Bumps the power output to 430hp/1200+ lb/ft of torque.   I put one on my cousin's 36' 2000 Country Coach Allure with the Cummins ISC about 15 or so years ago when they were available, and it totally transformed his coach.  Kind of sorry I did that afterwards as it made it nearly impossible to keep up with him.   Granted his coach is only 36' with one slide and towed a 20' enclosed trailer weighing around 8k loaded and with our 40' Dynasty we were towing a 13k pound 26' enclosed trailer, but still, it was hard to run with him up the grades.  

And I'll get 10 MPG if I'm not towing and doing 60-62.  Gotta hand it to Mr. Banks.

[zmotorsports]

9 hours ago, VinceB said:

And I'll get 10 MPG if I'm not towing and doing 60-62.  Gotta hand it to Mr. Banks.

 

Yes, plus the lighter overall weight of those with the ISC was already an added benefit, even before bumping the power.  My cousin's 36' Allure weighs right around 26k pounds and ours is already more than 10k more than his before we even hook anything to them, so there was a big advantage already.

 

Seeing you mentioned your traveling speed and economy, funny story.

 

I generally travel around 65-67 MPH which seems to be where our coach is happy.  Not a fan of going much faster because tire ratings and for safety margin but that seems to be where I like to travel.  On average I net right around 7 MPG.  When we were towing our enclosed trailer loaded it was closer to 6.75 and when just flat towing we are between 7 and 7.25 the vast majority of the time.

 

On one trip about 10 years ago, we invited my wife's sister and her family along on one of our trips as they had just bought a bumper pull travel trailer.  Her husband at the time would NOT go above 55 MPH the entire trip.  🤬  I think he was afraid to be behind the wheel of that setup as it was the first time he'd towed anything.  For that entire trip as I tried to increase speed and "hope" he would keep the gap somewhat tight, he would just drop behind in the mirror.  I did notice however, that trip we got the absolute best mileage we had ever gotten out of our coach at 9.5. 😲

[VinceB]

5 hours ago, zmotorsports said:

 

Yes, plus the lighter overall weight of those with the ISC was already an added benefit, even before bumping the power.  My cousin's 36' Allure weighs right around 26k pounds and ours is already more than 10k more than his before we even hook anything to them, so there was a big advantage already.

 

Seeing you mentioned your traveling speed and economy, funny story.

 

I generally travel around 65-67 MPH which seems to be where our coach is happy.  Not a fan of going much faster because tire ratings and for safety margin but that seems to be where I like to travel.  On average I net right around 7 MPG.  When we were towing our enclosed trailer loaded it was closer to 6.75 and when just flat towing we are between 7 and 7.25 the vast majority of the time.

 

On one trip about 10 years ago, we invited my wife's sister and her family along on one of our trips as they had just bought a bumper pull travel trailer.  Her husband at the time would NOT go above 55 MPH the entire trip.  🤬  I think he was afraid to be behind the wheel of that setup as it was the first time he'd towed anything.  For that entire trip as I tried to increase speed and "hope" he would keep the gap somewhat tight, he would just drop behind in the mirror.  I did notice however, that trip we got the absolute best mileage we had ever gotten out of our coach at 9.5. 😲

That reminds me of a fuel stop I made in NM  - can't recall where. 

The truck stop was lined up like crazy and it was late in the day so I headed to the private station across the street.  When I paid I mentioned the significantly higher price. The owner, who was working the register, told me, "Just wait, you'll get the best mileage you've ever gotten."

He was right. I got 11.5 that tank. I made sure I stopped there again on the way home and wanted to ask about the fuel but it was the owner's day off and the kid behind the counter had no clue.  The next tank was only 10.8 because of the headwind heading West.