Do you find your rig under power and Tying up traffic on Two lane roads and what fuel mileage do you get not towing and towing
1. No. If you find your coach underpowered, what are you using as a basis for comparison?
2. Towing: 8 mpg No towd: We never do that.
I've usually been able to do the speed limit on 2 or 4 lane highways. Does traffic line up behind me. Sometimes. Usually by overly stressed 30 somethings hurrying to get somewhere before it's gone.
I've also gotten around 8 mpg. Didn't seem to matter much towing or not. But my toad was a 3500# car so not a lot of weight.
Larry
We always tow the Jeep, get 8 mpg. Just weighed the coach a bit over 31K. When taking off don't be Afraid to mash the throttle your not going to hurt anything. If I soft pedal mine it is Sluggish.
Short answer: No.
Long answer: Often when I was employed as a salesman, on a demo, I was told "this rv has no power, that would happen on 300, 350, 400, and 450hp rvs. I would say, "ok let's do a test from this stop sign at an onramp to a highway with a speed limit of 55. Now do not expect miracles, remember this rv weight is approx. 30,000 lbs. Now, stop, accelerate floored until you enter the highway at that bridge there, it is approx 1/4 mile. Then look at your speedometer, and tell me how fast you are going." They would, and usually they would say "60 mph." And I would say, "now slow back down to 55mph, they love to give out tickets on this stretch." Usually that was followed by, "you really do not feel the acceleration."
As far as slowing down on the hills: I had one customer who twice a year traveled from the SF Bay area to LA and they would overnight at the same park. His rv had 275hp small block diesel, his friend a 400 hp big block. He said, I can not keep up with him on the hills. He gets to LA 30 minutes before me. I pull into the campground, my friend already has me checked in, and guides me to my spot, and has my favorite drink prepared. "I love my 275hp diesel, and I get 20-30% better fuel economy than he does." What I'm saying is, you are not driving a car, so just be aware of how much weight you are driving. That applies to speed and stopping distance allowed for. My experience taught me new to rv drivers, never allowed enough distance between their rv and the vehicle in front of them.
For a house on a truck it has good power.
7.5 mpg towing, never drove it far enough to determine MPG when not towing.
Exactly 8.0 mpg over 115,000 miles from the DDEC readout. About 10 mpg without toad unless a lot of mountain driving. It's a rocket at sea level and I usually use full throttle off stop signs, freeway on ramps, etc. Toad can be felt a little on steep high altitude passes but does drop the MPG. Usually cruise at 62 mph. Have never been passed by a big rig from Bakersfield to Mojave on the 58 grade.
Pierce
You would have to drive a bus with a 600 and drive it hard and still have mellenials flashing their lights at you from behind wanting to do 100 while texting or taking a selfie. Is the coach peppy enough for you ?
Jack is correct. I drive an ambulance, they train us to scan ahead constantly to be able to recognize possible problems before they happen. If you can predict an incident up ahead before it happens you can prepare for it and make the correct decision. Need to constantly scan, windshield, both mirrors, and instruments as well as being aware of what is going on behind us. It keeps the brain active preventing something called highway hypnosis, preventing you from recognizing possible danger.Also something called pre-braking. Keeping your foot hovering over, but not touching the brake pedal can also help. Give you a quicker response time on the brake.You can also use the weight of your vehicle to slow you down without slamming on the brake. These bad boys are heavy, it takes a lot of energy to get em rolling. The weight can be a benefit as without engine energy the rig will start to slow down on it's own meaning you use less brake pressure saving those expensive brake pads. Always assume the idiot in front of you is going to do something stupid, expect it, plan for it. Have an escape plan that adapts to your environment as you roll down the highway.You,re SA (Situational Awareness) has to be 100% every time you get behind the wheel. We are all guilty of allowing our attention to be diverted (me included). It takes a lot of skill and discipline to drive one of these bad boys. Fatigue is another killer. So many times we have rolled on motor vehicle accidents where people simply just fell asleep because they convinced themselves they could make it just a little but longer.I'm not an expert on this subject (even though I play one on t.v. old joke). Just throwing my devalued two cents worth in.
Hey Grey Wolff sounds similar to the Smith System we were taught continuously over my career. Always look for an out! And I agree with assuming the other drivers will do something stupid. That has kept me from being involved in quite a few accidents over the years.
Agree with everyone. Our coaches are not NHRA 1/4 mile racers. Any speed deficit is in our (incorrect) expectations.
The shop that works on our coach is a big rig class 8 repair shop. So when they first took the coach out for a test drive. They said holy cow, That coach hauls butt.
The main thing that slows my coach down on 2 lanes are curves. When I start hearing stuff rearranging itself in the cabinets and the fridge. It's time to back off. If traffic piles up. I just look for a pull off spot and let everyone pass.
As for fuel economy. We always have the Subaru out back (3000lbs) so pretty light. And in the past had a Mercedes SUV on a trailer (6000lbs) We live out west in Washington state. So no matter which way we go. There be big bumps to climb. Prior Owner (Reg) lived on Vancouver Island, BC. So the same thing. With 148,000 miles on a 450HP M11. Lifetime fuel economy is 7.8mpg. When we first bought the coach it was 8mpg.
Grey Wolf to Grey Wolff,
Yes, that's why I always try to fuel in the morning instead of waiting until I'm tired in the afternoon. Early morning finds most in bed and less traffic.
I watched a really nice 40 footer put a cement light standard almost 2 feet into the side of his coach at an Arco station. He backed out into the street and took off leaving parts everywhere. Said he was tired out the window. Never even got out to look at it.
Also good to find a place to stay before dark in new areas.
Pierce
With the exception of jor here I never remember any repeat customer downsizing their motor in a new to them rv.
Lots difference from Midwest and east coach users versus the western Rockies.
Hills versus mountains at altitude.
Banks engineering made up a comprehensive power upgrade kit long ago. Raised 300 to 400. Not available but dr diesel and others may have altered fuel plates to increase power and mpg.
The trans handles it easily it seems because of the light weight of our coaches.
You are probably type A personality.
If you pull up to an intersection with two lanes on your side and one lane has a car in it and the other is empty do you make sure you are in the empty lane. Some will just line up behind the one lane with the car in it.
Correct fan controller reduces power loss. Resonator. Donaldson blu tech air filter. Adjust valves and injectors.
Lower rolling resistance tires helps.
I did every step listed plus a few more. And I have a m11.
Good luck in your search. The banks kit was the bomb
Source engine power up parts.
I don't want to sound snobbish here but when I bought my Phonix they wanted to sell me the 45 foot model as that was what they were only making at that time. I wanted a 40 ft model but also the 600hp ISX Cummins. After some negotiation on what I would loose with the 40 vs the 45, we ordered our Foretravel. Now imagine 40,000 lbs loaded with 1850 ft/lbs of torque and 600 hp. I acatually had to learn to take it easy as it was so easy to climb hills at 65 and speed on the flats. After the first six months I started to drive it like my previous Foretravel and I have since averaged 6.8 mpg always towing. Not trying to compare, but with the newer coaches power has not been an issue for most owners.
Mine gets away from a stop light with the traffic, If you apply plenty of pressure on the right pedal. On the highway for the most part no one is waiting on me. Sure we all want more horses. Just like when I was trucking in the early 70s had a v12 with twin turbos and wanted more.
And nor is it with our older coaches. But of course it depends on the owner and their expectations and perceptions of what constitutes a "power issue". We are retired and not interested in driving like our hair is on fire. And so our 450HP M11 does great. And the 450HP M11 isn't over stressed like the 650 is and so doesn't tend to suck valves.
If a person insists that their coach NEEDED 650HP and it only came with 600HP They "might" end up having it in the back of their mind that the 600 (while good) just can't live up to 650HP.
We have a Cat 3126 300 HP. I swear that it likes the 6+K# race car and trailer behind it.Maybe it makes the turbo boost more, it's beyond me, because I can't even tell it's there.
I run 8's in the 1/4 mile at 149 MPH in my Duster, then jump in the MoHo. Doesn't bother me a bit. The Cat has all I want.Love the feel of all that boost when it kicks in.
All my RV's have been toads, so it never bothers me. I always laughed at the FT customers, because they were all retired, and in a hurry to go no where.
I drive ours at 62-65 MPH. get well over 10 mpg most the time. It averages ( average, not once in a while ) 8 mpg with Jeep Wrangler.
Sure, I get beer cans thrown at me, and the California wave at times, but hey, I am in no hurry, because I am probably going no where important any way.
Like Big Dog said, these are not NHRA drag cars.
Just sayin'
Chris
I just can't make myself floor it from the stop sign. Just a lifetime of careful driving and paying my own repair bills or doing it myself. Starting from a dead stop it really does seem slow, but I almost never have trouble matching the speed of traffic while driving up the on ramp. When driving along US 287 towards Amarillo and having to drive 35 mph through some of the small towns I've noticed that if I stop at a light, I blow away the semi's getting up to legal speed. I have a stock 325 horse all mechanical C8.3. I average around 8 miles per gallon, and I'm happy with that. It's about what I got towing a 24 foot travel trailer with a 1990 suburban.
I cruise at about 62, and pull over when there's a big line behind me going up a mountain when it's feasible.
Don't know about your throttle, but the Cat is computerized. I can barely move the coach when cold, then the more it warms up, the more throttle I have. Built in protection.
I am with you on flooring it. I had a Cummins Dodge pickup, man you could just feel those U joints crying out. But with the Cat throttle, I can floor it, and it only applies as much as it can handle.
Funny, went to grab the throttle linkage to give it a little romp in the engine compartment, and there is zero linkage. All handled by the computer. Fuel injection and turbo boost. Love it.
Now the Duster, I floor it to 5500 RPM's, and let go of the transbrake button. 1.25 60's!
Chris
Unlike a car, your 8.3 is not going to last any longer if you ease off the line or floor it every time.
We responded to emergencies with dead cold Detroits out of the station with the first shift at 2300 or 2400 rpm. No block heater. That's moving in less than a second from the time the engine lights up. They never complained or broke. Designed to be driven that way.
What you do have to watch that effects engine life is EGTs at high altitudes in warm weather. Especially with mechanical engines. Keep rpm up with partial throttle to keep EGTs down.
Other than that, give the oil temperature time to drop before shutting down after any kind of pull. Turbo oil cokes and will shorten the turbo bearing life and any turbo parts in the combustion chamber will result in a big bill.
So, it's the little things you don't think off that effect the life of your engine. The big reason some drivers can triple the B-50 life of their engines and others don't make it that far.
Pierce
Yup, Dr Diesel had his coach towed into our Coeur D Alene FT shop, after he had the motor put back to stock. Was having us help him get a new engine under warranty.
He was a big bang (pun intended) around here for a couple of years. He is long gone with a few peoples money.....Just sayin'
I'am all over performance, but all my new stock stuff I leave alone. Just my personal preference. If it was good enough for the manufacture, it is good enough for me.
CW
I drove/sold alot of subsequently turned up 8.3C mechanical Cummins. Lot of customers with them still. No issues. Better mpg like chris reports.
Dr diesel local rep had me drive his 5.9 crew cab with a small camper on it. Amazing power.
Heavy smoke. Kills rings after a while.
Electronic engines have approx 5% better mileage vs mechanical and common rail, another 5% better. ECM controls the fuel better at altitude.
Black smoke means higher EGTs and less mileage with a diesel. Not like rich mix with gas engines used to cool them.
Pierce
Been my speriance hot rodding diesels usually will come to no good end. The afore mentioned V 12 used to kill itself about every 125K. with mr flatfoot helping.
I from the maritimes times and we have Long hilly roads and are main highways Have stretches where there are only two lane traffic till you can come to a passing lane going uphill and I've seen myself down to 25 to 30 miles an hour for a mile and up to 5 miles uphill climb with tractor traders at your back bumper it seems the six speed Allison has a wide Shift range about 500 rpm between gearshift I drive tractor trailers 15, 18 speed where you can split gears I just feel I am tying up traffic I am not trying to race with the traffic Just keep up with them or keep out of there way it the first time I am using an Allison transmission and being a truck driver it is very frustrating getting behind a slow motion vehicle when you're trying to keep your momentum uphill just asking because I see gas RVs just fly by me are speed limit is 60 to 70 miles an hr And when you approach a vehicle doing 25 miles an hour it's not a Safe feeling and no one can tell me that it is safe
My discussion with prospective owners included that the more power models allowed you to not play as much with the trucks in the slow lane as you stated.
A few coaches I sold over the years were left lane coaches if they were not towing.
36' 300 cat ORED was a good one that way.
Thanks caflash Bob ---- It is good to know that we have a fast lane coach!! I always wondered how life would be in the "fast lane". Thanks and have a great day ---- Fritz
Rick,
You have a 1999 36' U270 with a Cummins ISC-350. You have one of the lighter coaches from that model year so your performance should be pretty good. What do you pull for a tow vehicle?
Have you played with the MODE button on your Allison touch panel? Try driving with mode ON and with mode OFF. One of those settings should make your transmission more responsive and quicker to down shift, thus keeping the engine more in the "power band".
How long since you changed fuel and air filters? Diesels need lots of air and unrestricted fuel supply to perform up to specs.
If your engine IS actually performing at less than specified levels, there is one more possibility you might want to investigate. The ISC CAPS fuel system on 1999-2003 coaches has been the source of problems for several Forum members. See link below for more info:
Cummins ISC CAPS intermittent stop engine light (long!) (https://www.foreforums.com/index.php?topic=36481.0)
My little Cat 3116 250hp mechanical engine in 36' U-240 is slow off the line in first gear. I get no smoke at any throttle position at any time. First gear shifts to second at 2100rpm, then second and the rest run out to 2650rpm. I always do WOT take offs. I tow an 11 chevy HHR(3150lbs.) and it tow speed limits me to 65 or less. 2000rpm in sixth gear gets me down the road at 64mph. 8.5mpg towing in hills is my lowest mileage and 10 mpg on long flat runs.
I live in the Rocky Mountains with passes both directions. 35-45 mpg on steep grades towing or not towing. Plenty of power on the flats and small grades. 300 hp, 875 torq? 8mpg. As long as it makes it and doesn't over heat, I'm good. Just came home from a trip to 9600 feet. 195 was the high temp. Very pleased
Charge cooler leaks is another. Changed lots of them. Kills boost
Are you using the up/down arrow to do a manual shift to keep the engine spinning?
Doing this made an improvement on ours when climbing a hill. Also, If the trans is in the eco mode. It is usually very reluctant to down shift. It's a different beast than when I owned my 427HP 9 liter Mack/13 speed and 500HP Cat C15 Kenworth W900/15 speed.
I'm tow 2020 Jeep Wrangler it works good and I don't mind traveling on the the 4 lane's she a little slow on the long grades but rolls a long good on the flats but on a 2 lane if you happen to come to all most a stop at the bottom of a hill it takes for ever to get here up to speed Take off from a stop on the flat in know time your up to speed on the flat with the Excelerator to the floor I was just wondering if people found the same situation and if this was normal I just don't feel good tying up traffic when they have no room to go around you she give a little puff of black smoke when she shift A mechanic told me this was normal that it was a delay with the turbo besides that it does not smoke if you Excelerator hard she seems to respond good no flat spot over all she works good just feel it takes for ever to recover her speed I try to Count her down shifts but have a hard time figuring out what gear she's in she down shifts at 1600 rpm and up shift a 2150 rpm in power mode
And in the maritimes here with the hill I always drive her in power mode in the us on the Interstate a driver on the economy mode and usually keep her around 65 miles an hour or keep up with the traffic. Never towed a Jeep yet in US only solo it a different rig on two line at 50 mph
Guess I'm a lucky one. Old Faithful has the "Banks". Info says 75-100 HP gain. (According to brocures, invoices) Larger CAC, turbo is different, erg, boost gages. Get 8.8- 9.4 75000 miles
No issues, just wish he had a jake...
Honestly my 88 was quicker ! 300hp cat
Have you done a fuel pressure test. There is a pressure relief valve on the side of the fuel pump that is prone to wear. I had to
change that on my last coach. Also the transfer pump could be weak. When I changed the relief valve it was because one morning
I get going and I said to my wife, this thing is gutless. The day before it was fine. After I changed it the fuel pressure was just within
tolerances so I was thinking of changing the transfer pump but as the power was back I left it. Also when were the valves set.
I just purchase this coach in Dec I have put about 6000 miles on it this is my first trip towing a Jeep behind and I really feel she under power in the hill I think I'm going to bring it in to cummins to check her over it's 21 years old with 110,000 miles I've change all filters fuel and air are new oil change there know missing sound good she run on the flat 70 to 80 hit a hill she just drops on 1 hill a very long climb she fell down to 25 to 30 and just held it there to the top and then took off on the highway I keep up with the traffic when I hit a hill they walk a way from me go to bring her in to get her check over would love to come along side an other Foretravel to see if I could fallow it
Do you do any down manual shifting as you star going up the hills, as opposed to just letting the transmission shift on its own?
I tried it once or twice and it doesn't seem to downshift. I press the button and it waits till it hits around 1600 RPM then it seems it downshifts and the RPM go up. I can't tell what gear it's in the display just shows 6 . If I have it on cruise control it doesn't downshift at all. Tell you the truth these hills in the maritimes it seems like 80% of the time she's in 5 gear . I have an appointment to have oil changed at Allison transmission shop , going to get them to check for any codes . I'm thinking it's more of a transmission shift problem than engine problem .
I shift down manually most of the time. The 4 speed has big gaps between gears and it can "hunt" back and forth between 3rd and 4th heading uphill at certain speeds. Gets annoying on long grades as it can't pull it in 4th but accelerates quickly in 3rd. Starting steep downgrades on two lane roads, many times I will stop at the top and then start down in 1st or 2nd as I don't like the abrupt downshift the Allison does and never sure when it is going to do it.
The Allison is at it's best when it shifts up or down at light throttle loading somewhere around 55 mph. Nice and smooth.
If I am marginal on cooling on a long grade at high altitude, I will manually shift down to keep the rpm and temperature where I want it.
Pierce
Some fresh Transynd and filters may cure it.
her temperature stays at 180 to 185 all the time does not go higher on the hill but I do have the Excelerator's always to the floor on the hills I do not let up for any shifting I noticed the big range between gears because it is only a 6 speed transmission
I do drive trucks tractor trailer's and in the 80's I had a truck with a 350 cummins with a 15 speed Standard and I've had loads where I was grossed 80,000 to 100,000 lbs going up the same hill at 35 miles a hr and here I have under 40,000 lbs coach and I'm going up at 30 miles with this 6 speed automatic I probably shouldn't be comparing it too but I find for a 350 Cummings and something weighing roughly 31,000 pounds and towing a jeep that she should be holding herself better in the hill I had a 34 ft motor gas walk away from me the other day climbing a hill this is my first time driving an Allison transmission and I feel it in the transmission maybe that's the way it is just slow and easy l drove it down to Florida last winter solo with out Towing and on 95 all the way dawn and up in the us I found it reasonable but as soon as I hit the hills in New Brunswick and Nova Scotia it was slow going I just leave it in power mode and didn't bother with the cruise control it just slow going one hill after an other she run right along on the flat TIL you hit the hills would love to be able to fallow an other 36 Foretravel travels to see if they performed a same
I don't find my coach to be lazy however it was a bit disappointing when paired up against my friend's 2016 chevy 2500 diesel and 5th wheel. He absolutely leaves me in the dust. But after my old Winnebago with a Ford 460 my Foretravel is a rocket ship, even though it's a 42' tag axle coach towing a 6000 pound trailer. It's plenty fast enough when you consider how much stuff goes flying when you have to do a panic stop.
You are not wrong here. When I have my own 6K+ race trailer behind I get better MPG then without it. High 8's and sometimes more.
We have the same coach, 99 U270.
350 hp was my bottom line, anything less has been disappointing, having said that my KW with a 300 hp turbo Cat pulling a previous 10000 lb trailer with a manual 9 speed was way faster.
This coach with the 350 hp through the 6 speed Allison is really responsive, it's not often that we notice hills east of Colorado, it purr's ! It's no problem to find we are going way quicker than we want. We tow a Jeep wrangler and don't realize it's there, the rear view camera reminds me.
If you are sluggish get a Dyno test.
I love driving ; slow and sluggish and we would have sold the rig a year ago.
- Responsive
- keeps up with traffic or leaves it behind
- Plenty of reserve power at 65 /70 mph
No it's not a BMW off the light, but it's not far behind.
You should be relaxed, no pushing on the peddle thinking you can squeeze our another two or three mph, it should have enough power to bring a smile to your face, there must be something wrong with your coach.
PS: MPG, it is what it is, that's why there is a big tank and the fuel savings card.
Your Allison should be locking up so no advantage for the manual transmission except for better ratios available. We only have a 4 speed so it really drop revs when it shifts. When your Allison goes into lockup, you should really feel the difference in acceleration.
You should make sure your boost is up to spec. A crack in the intercooler (CAC) may have gone undetected and not allow full boost. Fuel supply is always suspect and if you have a mechanical pump, it could be the return valve or the lift pump.
Other Cummins owners may have had and solved like power problems and give some help here.
Pierce
Yes, the Allison 6 speeds-- both 3000 and 4000 series lock up at higher RPM in 2nd gear (feels like a mini-shift) and in all higher gears.
I am on the road now and playing with the manual shift arrows did not realize how big of A difference between gears There was. pressing the arrow down from 6 to 5 and nothing then I kept pressing and realize she was all the way down in third and sometimes second gear then she started to pull good. I was dropping one gear on the arrow but she had already dropped a few more gears didn't realize how Highup I was. Im on a 200 mile trip on a two lane I'll see how I get along today go from Halifax to Yarmouth it a hilly run Will try the power mode and try the economy mode had it over six months and still getting used to it
IF (certainly not required) you want best control in technical/mountain driving, leave the transmission in economy mode and use the up/down arrows to select the best gear for current conditions.
Sure, you can leave it in power mode and "D", but the transmission is very REactive (seeing what happened well behind you). You can be PROactive-- seeing what is coming up and selecting the proper gear for what is coming up.
That's one thing I don't like about that Allison shift pad display. It does take a bit of getting used to.
A lot of us with the M11 have the VMSpc that displays max gear and the current gear. Not sure if the VMSpc works on the 8.3 engine. Roger might chime in on that. VMSpc is a OBD reader that displays as an electronic dash on a stand alone computer screen. Great tool that monitors much more than the dash gauges do.
When I first purchased my coach I had gas Bounders passing me on grades while not even towing that got my attention !!
I solved my sluggish 8.3 Cummins by replacing the turbo wastegate actuator. It was spilling off boost, easy to test by squeezing off the rubber hose that connects to it and take it for a test run.
A boost gauge is your friend. Also replaced the fuel return valve and deleted muffler.
Western state grades I rarely slow too less than 42 mph towing 4600# Jeep.
Cummins 4038544 NEW HX35W HX40W Turbo Actuator (https://turboturbos.com/products/a-0006)
No my coach is not lazy. But I am. I'm retired. Plenty of time. And I don't like much going over 65. If the speed limit is 55 I go 54. Really not in a hurry. I found that using the transmission in manual mode makes going up hills much easier. Going down hills, I use the retarder to keep the speed where I am comfortable with. I do not like it to speed up to much. I am getting 8.1 mpg towing a jeep grand cherokee, and the coach is pretty loaded with tools and stuff. Jeep has some stuff as well. I like to keep the fuel tank half or better filled, and the water tank half or less. Waste tanks depends. I try to empty them, but sometimes I like to keep them up and let them bash around a bit with some dawn and borax in them to clean them up a bit. Only me, and a big dog in it.
I see 5th wheels/ pickups going real fast and think that I would not want to be towing that hunk that fast. To many people in a hurry, but then when I was younger so was I. The wisdom of age I guess.
Bob
When you are climbing a hill what is your boost. On the Dynasty I had the Allison had both the gear I was in and the gear it was
calling for on the gauge. I found out the Silverleaf could be programmed for that so all is good. I have driven around the Cabot
Trail with the old Dynasty, a 8.3 Cummins 325 HP with no problem.
Yes, some Allison shift pads have a single window that indicates ONLY the gear selected (for example when at a stop and select "D" it will show "6".
Other shift pads have two windows-- the right one as above and the left the actual gear you are in.
Yes, Silverleaf or the much less expensive Scanguage D can show the gear you are in for those with the single window shift pad.
dont have a boost gage have to look at buy a program to put in my I pad and hook in to dialysis plug on coach on old mechanical 350 you could change the button in the injector pump on these electronic ICS I have no idea on how they adjust fuel pressure
What boost do you guys hit? I hit right around 26 psi when I am really cooking. I've noticed lately though it really only ever seems to hit 24-25. Maybe it's time to start leak testing before things are an actual problem (or I overspeed the turbo). Cummins ISM 450HP.
Boost will depend on temperature and altitude. You might have to spin the engine 2-300 rpm higher to get the same boost and turbo will be also spinning faster to get the same PSI boost comparing sea level and 5000 feet. Good short read at: Boosting With Altitude - How Elevation Affects Turbochargers (https://www.dieselarmy.com/engine-tech/boosting-altitude-elevation-effects-turbochargers/)
Pierce
On my 350 cummins my shift point is at 2150 rpm if I manual down shift around 1700 rpm it jumps up around 2100 rpm what is considered over raising I was toll not go over 2000 rpm years ago. She down shift a 1650 and up shift at 2150 automatically but manually shifting what do you shift that
I think you were "told" some misleading information. Our C8.3 RPM numbers are listed below. Our engine loves running between 2000 and 2400 RPM. The numbers for your engine should be very similar.
You can easily find out for yourself - just register your engine at Cummins QuickServe Online. Registration is free - all you will need is your ESN (Engine Serial Number). Once registered, you will have access to a wealth of info about
your specific engine, including a list of RPM numbers.
Cummins QuickServe Online (https://quickserve.cummins.com/info/index.html)
ADVERTISED HP: 300 @ 2200 RPM
GOVERNED HP: 285 @ 2400 RPM
TORQUE PEAK (lb-ft): 820 @ 1300 RPM
HIGH IDLE: 2760 RPM
GOVERNOR BREAK RPM: 2450
Nothing to compare it to so it runs great as far as I know.
I removed the radiator and air cooler from the coach rad is rotted out and did an air test with soap and water on air cooler and it's leaking all over . With air leaking I would lose my engine boost I believe this is the problem with it being so lazy they tell me with lost of boost comes lost of power looks like this is my problem
Would a dash boost gauge have identified this low boost from leaking intercooler?
Probably it would have been low I think
VMSpc shows boost, no need for a single gauge.
Yes a 99 isc electronic c8.3 could have used a VPMS to show the low boost. As did his right foot and butt dyno
Rick, you are correct in that a leaking CAC will cause low boost and sluggish power. Years ago I was finding our ISC 350 sluggish and did an inspection of the CAC visually and noticed 4 good sized holes caused by fuel cooler bolt missing and cooler was vibrating against it. Took it off and cleaned it up and repaired it properly with small aluminum strips of channel just big enough to cover hole and clip to either side of good part. I put very carefully a thin layer of Devcon Aluminum paste over the area first then more over the total area of clip and shaped it to go about 3/4" past either side, on each one. Left it 24 hrs then filed it smooth and pressure tested to 45 lbs. That pressure stayed good overnight so I new the repair was good. My boost has been even ever since and can go up to 32lbs when timing is right. I do have a Banks system on it so my reading is supposed to be up there.
So, it looks like a new one is needed for sure if there are numerous air leaks.
John H
Before investing in a new intercooler, take the old one to a welding shop that hot roders/fabricators use. They can work magic on aluminum.
Pierce
You can put a new core in for a lot cheaper than a new intercooler.
Going to bring radiator and cooler and fuel cooler to Heavy equipment radiator and heat exchange shop and have them put a new core I was thinking of Atlas but there on the west coast and I'm on the East Coast and a different country. so I think my best option is just have it record. I've ordered the hoses and clams from Amazon and going to change all the air lines and fuel lines that are Hidden behind the radiator they're very hard to get at so while the radiator is out I shall do some pre-maintenance and change all the hard to get at stuff they look to be in bad shape there 21 years old The problem is I don't know where to stop it would be to hard to change everything into expensive
Radiator
You really have a lot of rust/corrosion everywhere and the radiator does not look so hot. But I guess I don't have to tell you that. I can see what you meant about not knowing where to stop. How does the bulkhead look? Lack of any kind of rust proofing there plus the design may indicate some attention needed. I'm not sure where I would even start.
Don't mean to mind your business but have you though about selling and finding a corrosion free coach before you go full time? Getting caught on the road with rust related failures can take all the joy of full timing and be really expensive where you don't have anywhere to do the work yourself and are at the mercy of a shop.
It almost looks like it needs to go to a shipyard in Mexico where they deal with a lot of rust and will be way less expensive. Was thinking of Guaymas.
Again, sorry for such a negative commentary.
Pierce
I just bought it in Dec the rest of the coach is in Beautiful shape body and paint the inside is just like the day It was built and has been upgraded. Every thing works on it. Tires are all new new battery's but I had to do the the bulkhead right after I bought it the first trip went down to Florida the steering box started leak had to replace it and now it started to leaking antifreeze and from the time I got it in Dec. I found it had no power it was lazy wouldn't pull her self in the hills slow taking off so when I took the radiator out tested the air cooler and sure enough that was leaking also. I got it for a very good pice $30,000 I figure With an other $25.000 I'll have it in top shape 55,000 I figure is cheap for a coach like this I can do a lot of the work myself and I have the building to do the work the lines do look bad . The frame and suspension all seems to be in very good shape the frame is like new but it's been a big project so far more than I thought it was going to be The previous owner lived in Ontario and travelled to Florida every winter so I presume he drove it in the salt and never wash off the salt with the Back wheels spraying the salt in the snow into the engine compartment the lines in the hose have taking a beating it's too beautiful of a coach just to throw it away I will do the rust prevention and rust check I do find it expensiveThe bulkhead was a surprise to me and I wasn't expecting the steering box to let go and the ad wasn't leaking at the time I don't know it might be a big headache in the long run My trade is automotive mechanic I'm sure learning a lot about diesels and coach's it's been a learning experience thanks to this form I got an awful lot of information and a lot of help and Brent has gave me a lot of advice in his articles and also others
The bulkhead repair has put you over the hump on having to worry about giving up. When you get the radiator and CAC done the rest should be minor compared to what you have done. If you can repair one of these then you are ahead of most members.
thanks it was scary at times not knowing what I was getting into but talking with people on this form I took the challenge and I think you're right the big articles are over with now hopefully my next project next summer will be the AC condenser and I'm hoping after that it will just be routine maintenance the previous owner has replaced airbags upgraded satellite dish upgraded the inside the headlights repaint out side he told he bought it in 2012 and rigth off the bat put $30,000 into it with redoing the inside repainting it would graphic scheme reupholstering all the furniture in it remove the carpet and redoing the floor with tiles all done in Texas Gave me all the Invoices to prove it and all the maintenance records of it from the time he had it in 2010 to 2019 he did look after the inside and outside very well except the engine compartment and the underneath I really enjoy it and learning a lot but I have to admit I'm starting to really enjoy the work and understanding how well-built they are
Rick, Atlas in south Texas, Corpus Christi if I remember. You cannot repair the CAC by welding etc. Too much carbon inside and will just blow apart while trying too.
How many leaks are actually in it and how big a leak are they,?
Do you have pictures of these leaks and if so send them too me. My email is on my profile
Johnh
Most coaches have been optically improved. Our coach looks ok. Not great.
Mechanically its a 9. Every part massaged. Zero ego to do the hidden stuff first
John they can't be welded but can be recored. I have one done in Campbell River and when finished it look like new.
It's clear after looking at your later photos that you do have the space and the talent to do the repairs. The rust on the tubing looks deep enough to possibly fail down the road with a loss of hydraulics, etc. I would think photo documenting one area, removing all that will unbolt, removing the rust and using an excellent black frame paint like Summit Racing's black frame paint. They offer all the supplies needed for any kind of restoration and do a huge business. I used their $100/gallon frame paint on the entry step on our U300 after blasting it and etching it. I brushed it on, never put any tread to cover it and I can't see any wear on the paint at all from our shoes or the dogs. Shiny black too. Summit can point you in the right direction as a lot of products they sell are to restore vehicles much worse than yours.
Buying hydraulic hose, pipe, stainless cost only a fraction of what the hardware or auto parts store charge. You probably found out how cheap steel is when you go to a wholesaler and buy in 20 foot lengths.
Keep photos coming as you progress.
Pierce
Foretravel used graded steel in their production.
there are 6 lines that are bad going to replace then two fuel lines ( fuel lines from tank to engine filter have been replaced when I did bulkhead) two air lines from Compressor going to air tank and two water from compressor to block. The rest I will hand sand and put good paint then put some rust check oil I would like to make an underbelly to stop the winter driving conditions when I go and come back from going south each winter but that might interfere with cooling the compartment down I don't know if The rusted is from winter conditions or is it the way the previous owner stored it in the building without ventilation and no heat it just the compartment that got all this surface rust it's not rotten it just looks bad like paint peeling off
Up date on my lazy coach with no power after working on it all winter. spring is here and had it out for its first run this year over 200 miles I replaced the radiator and air cooler, fuel and hydraulic cooler and all hydraulic hose injector lines and fuel transfer pump and had the valves adjusted and had the engine computer brought up to date there was over 30 up date that the cummins mechanic install I don't thing it was ever brought in to a cummins shop . ( the up grade to the computer was the only think I couldn't do myself Ididn't have the cummins program )plus I did the front and back brakes pins the front brake were dragging when I jack it up couldn't turn the wheels .plus other repairs under coated and paint the frame.. Well it was like night and day can't believe the power and how well it pulls I have no problem now keeping up with the traffic or leading the pack she can handle any hill here in the maritimes I am no longer tying up traffic I figured the coach did over 10 miles per gal the turbo boost was over 25 psi on the silver leaf horse power on a pull 340 to 353 hp how it's fun driving it and enjoy my drive can't wait to pull the Jeep to see how it handles on our first outing keep an eye in you mirrors and watch me go by I was getting discouraged with all my repairs but now I'm proud of what I accomplished and the learning experience over the winter now it's time to enjoy it.by the way the alternator just stopped charging LO.L that a small job after this winter and last winter the bulkhead, fuel lines, steering box windows I'm ready to go anywhere now.
In a former life, I worked for a diesel performance shop. We dealt with the 3/4 and 1 ton trucks with the common engines. The ISM in my coach is a big brother to the 1000hp 5.9 ISB's I am most familiar with. I've already drilled my exhaust manifold for a thermocouple and once I get the line run, I'll be able to see just how much EGT margin there is. Once I know that, that should give me a good idea of how much more power can be thrown at it without hitting EGT limits.
Anyone know what the 2002 ISM450 EGT limits from Cummins is? I know the 2003 5.9's were 1450*F continuous for 30 mins, measured pre-turbo. Shorter duration allowed for slightly higher EGT as well.