Is 360 hp enough for for 38-40 ft class A

Snomas wrote:
My 350 Cummins pulls a 4800# toad and I don't even feel it. I go over the rockies all the time and if that is not a test nothing is!!!

well I have a 450HP ISL 40 ft and loaded with my gear and towing a 3800LB toad and towing through BC,Washington and Oregon its no speed demon. I had a 350HP ISC and traded it off because of poor power
I seriously laugh at the guys with the 275HP 38 ft ISB and claim they do 45-50MPH up 6+7% grades. heck I can only go 48-52 with my 450HP ISL

pointrow wrote:
The reason I ask this question is because I currently run a 13 Duramax pulling a 34' 5th wheel. Plenty of power and I can drive at what ever speed I want and clime any hill with the best of what is on the road.

You say "hills". Have you had this setup out west in the Rockies?

We have a 2014 26,000lb 34 RV with the 6.7L 340hp engine and I can tell you on the grades above 5% 45mph is about max. Mild hills and 65mph is no problem. Can't feel my tow vehicle behind the RV unless I hit the grades. So when you say "does it have enough HP", its all subjective. To me my 340 HP RV is not enough, for my Dad he says its plenty. That all being said I could not find a MH plan that I liked with a engine larger than 340HP and still be under 36' (exact measurement).

So if your just hanging out in the Midwest you might be fine with 360HP class A, if you come out west you probably will not be happy with the power.

I have a 330 HP Cat , 7.2 440 cubic inch with 130,000 miles on a 37' #3 slide Safari pulling a 21' box trailer with a Rhino and a Mini Cooper inside. It is adequate for most hills up and down and will maintain 35 Mph to 50 Mph. 8 percent grades are the ones that get you to the lower speed, but it is all about the safety going down hill that you will experience with the exhaust brakes.
The 8.2 plus Liter or 540 cubic inch engines are of course a little faster and brake stronger but not that much better for the 1-1.5 MPG less fuel economy. They both have the 3000 series Transmission. Don't get fooled buying a small block , no torque new Cummins of 350 Hp. TORQUE rules.

RayChez wrote:
OLylen, how did you boost the horse power on your 330 hp Cat to 396 hp and boost the torque from 860 to 1050? I have heard this from other RVers that it can be done but I never have asked how it is done.

You set the parameters on the computer! Any good diesel shop can do this. Make sure your off warranty.

azdryheat wrote:
It's not the HP that gets a MH over the mountains, it's the torque. And these motorhomes have some incredible torque.

No, that's wrong. Repeat after me: one horsepower equals one horsepower! This is basic physics!

It boils down to a choice between performance and fuel burn. For an RV towing something, it's often torque that's more critical.

Back in the 1960's, with 4 children, we bought a Mercury Colony Park Wagon. Seats for 8, 429 V-8 with 4 barrel carb. It got 10 mpg on the highway and about 6 in town. I finally figured out why the in-town gas mileage was so poor.

The carb (a 4-barrel Holley, I think) had a float bowl that held about a pint of gas. If I hadn't take the barge to work, Momma did the rounds of the stores. Five miles here and park for a half hour, then 3 miles someplace else and park for 45 minutes. Without a modern vapor recovery systems, the gas in the float bowl evaporated while she was parked. If you evaporate a pint of gas every 10 or so miles, your gas mileage really suffers.

We finally got rid of that barge after the gas crisis, and got a Chevette for me to drive to work and a Taurus for Momma. Gas bills dropped by about 50%. We now run a 3.5 L Kia Sedona that gets around 20 mpg.

OLylen, how did you boost the horse power on your 330 hp Cat to 396 hp and boost the torque from 860 to 1050? I have heard this from other RVers that it can be done but I never have asked how it is done.

OLYLEN wrote:
Well I will say I have a Cat 330 HP bumped to 396 HP(OH! the Dyno will read HP too) and TQ. of 1050 and it pulls well with a four wheel trailer and towed on it. YES I know it's back there and anyone who says different just take the towed off and run the MH with 5000# less, it feels like a Vet. I would stay in the ISL or C-9 and above. Yes the others will get you to the top of the hill a few minutes later than these motors. Minimum I would go is ISC or Cat C-7 area with 1000# torque. I would not drop to the ISB even with the 360HP. It is in the big gasser class. And I know the V-10 and the 8.1 pull just as good as the diesels untill you are passing them at 55 pulling hard and they are at 35 and screaming. But that's another tail. JMO

LEN

Cat c7 has 350 hp and 860 tq not 1000 tq
A dyno measures tq. You determine hp from measured tq and rpm.

Well I will say I have a Cat 330 HP bumped to 396 HP(OH! the Dyno will read HP too) and TQ. of 1050 and it pulls well with a four wheel trailer and towed on it. YES I know it's back there and anyone who says different just take the towed off and run the MH with 5000# less, it feels like a Vet. I would stay in the ISL or C-9 and above. Yes the others will get you to the top of the hill a few minutes later than these motors. Minimum I would go is ISC or Cat C-7 area with 1000# torque. I would not drop to the ISB even with the 360HP. It is in the big gasser class. And I know the V-10 and the 8.1 pull just as good as the diesels untill you are passing them at 55 pulling hard and they are at 35 and screaming. But that's another tail. JMO

LEN

I play the numbers game, my setup has 60lb per hp and 19.4lb per ft lb torque.
Works great making mountains flat, just takes more fuel.
Dave M