Engine power do you find your coach lazy

Topic: Engine power do you find your coach lazy (Read 2649 times) previous topic - next topic

Re: Engine power do you find your coach lazy

Reply #25 – August 23, 2020, 06:14:09 pm

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.

Re: Engine power do you find your coach lazy

Reply #26 – August 23, 2020, 06:22:21 pm

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

Re: Engine power do you find your coach lazy

Reply #27 – August 23, 2020, 06:22:40 pm

Quote from: Cape Bretoner – August 23, 2020, 06:06:58 pm

...just asking because I see gas RVs just fly by me...

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!)

Re: Engine power do you find your coach lazy

Reply #28 – August 23, 2020, 06:56:40 pm

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.

Re: Engine power do you find your coach lazy

Reply #29 – August 23, 2020, 08:06:15 pm

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

Re: Engine power do you find your coach lazy

Reply #30 – August 23, 2020, 08:14:25 pm

Quote from: Chuck & Jeannie – August 23, 2020, 06:22:40 pm

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!)

Charge cooler leaks is another. Changed lots of them. Kills boost

Re: Engine power do you find your coach lazy

Reply #31 – August 23, 2020, 08:56:13 pm

Quote from: Cape Bretoner – August 23, 2020, 06:06:58 pm

I've seen myself down to 25 to 30 miles an hour

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.

Re: Engine power do you find your coach lazy

Reply #32 – August 23, 2020, 09:12:51 pm

Quote from: Chuck & Jeannie – August 23, 2020, 06:22:40 pm

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!)

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

Re: Engine power do you find your coach lazy

Reply #33 – August 24, 2020, 06:18:46 am

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

Re: Engine power do you find your coach lazy

Reply #34 – August 24, 2020, 10:41:54 am

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.

Re: Engine power do you find your coach lazy

Reply #35 – August 24, 2020, 02:22:02 pm

Quote from: oldguy – August 24, 2020, 10:41:54 am

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

Re: Engine power do you find your coach lazy

Reply #36 – August 24, 2020, 05:36:40 pm

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?

Re: Engine power do you find your coach lazy

Reply #37 – August 24, 2020, 06:32:15 pm

Quote from: rbark – August 24, 2020, 05:36:40 pm

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 .

Re: Engine power do you find your coach lazy

Reply #38 – August 24, 2020, 06:35:51 pm

Quote from: rbark – August 24, 2020, 05:36:40 pm

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 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

Re: Engine power do you find your coach lazy

Reply #39 – August 24, 2020, 06:45:55 pm

Some fresh Transynd and filters may cure it.

Re: Engine power do you find your coach lazy

Reply #40 – August 24, 2020, 07:05:57 pm

Quote from: Pierce & Gaylie Stewart – August 24, 2020, 06:35:51 pm

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

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

Re: Engine power do you find your coach lazy

Reply #41 – August 24, 2020, 09:04:01 pm

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.

Re: Engine power do you find your coach lazy

Reply #42 – August 24, 2020, 09:07:04 pm

Quote from: gracerace – August 23, 2020, 01:38:49 pm

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.

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.

Re: Engine power do you find your coach lazy

Reply #43 – August 24, 2020, 10:13:29 pm

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.

Re: Engine power do you find your coach lazy

Reply #44 – August 24, 2020, 11:35:53 pm

Quote from: Cape Bretoner – August 24, 2020, 07:05:57 pm

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

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

Re: Engine power do you find your coach lazy

Reply #45 – August 25, 2020, 10:37:13 am

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.

Re: Engine power do you find your coach lazy

Reply #46 – August 25, 2020, 11:08:30 am

Quote from: wolfe10 – August 25, 2020, 10:37:13 am

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

Re: Engine power do you find your coach lazy

Reply #47 – August 25, 2020, 11:15:04 am

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.

Re: Engine power do you find your coach lazy

Reply #48 – August 25, 2020, 11:26:13 am

Quote from: Cape Bretoner – August 25, 2020, 11:08:30 am

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

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.

Re: Engine power do you find your coach lazy

Reply #49 – August 25, 2020, 11:29:24 am

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

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