Hubby says we need more power!!

[Loving_God_s_Co]

We have a 2003 Holiday Rambler Neptune pulling a Jeep Wrangler. The hubby is frustrated with the lack of power that it has when we are pulling on to highways and wanted to know if there are any add-ons to boost the power??? We purchased this unit last fall as our first Class A and would like some guidance from the veterans!

[wildmanbaker]

Gods Country, first make sure it is running correctly. Getting good boast, and the intercooler is working and not plugged up and not cooling. Is the waste gate closing all the way? And, make sure you know what engine and transmission is in the MH. I have seen some of these with pretty large engines in them, and only 34 foot long. Same with the Transmission, is it shifting correctly and at the correct times. The fix could be a fairly cheap fix.

[John_Wayne]

If you don't have an allison 3000 trans you are limited by the transmission. It will not stand up to added HP and Torque if it's not a 3000. I think Bruce Brown has given you the right answer.

[Bruce_Brown]

Be careful with that one. According to the 2003 Neptune Brochure you have the Cummins ISB Low Torque engine rated at 275HP/600 lb/ft torque mated to an Allison MH2000 transmission.

Looking at the Allison Specs shows your transmission is rated for 300HP MAX with 780 lb/ft torque MAX.

HP wise you're close to the limit, and seeing as HP is a calculated number using torque and RPM, you really don't have a lot of room to play with that set up.

Bottom line - if you really want more power it might be time to start looking for a MH with a bigger engine and heavier transmission.

Am I helpful? :B :h

[tropical36]

Loving God's Country! wrote:
We have a 2003 Holiday Rambler Neptune pulling a Jeep Wrangler. The hubby is frustrated with the lack of power that it has when we are pulling on to highways and wanted to know if there are any add-ons to boost the power??? We purchased this unit last fall as our first Class A and would like some guidance from the veterans!

Don't know your length or your weight, but generally speaking, it's 10hp per foot, for adequate power. I guess he could put his foot to the floor, although I never do and don't expect neck breaking acceleration from any of them, let alone a diesel. I like the diesel for low end brute torque and silence in the mountains and it still fascinates me a year later and after having gas rigs for many years.

[Mandalay_Parr]

Manually keep it in the lower gears if need be and be content with slower accelerations.

[ScottG]

BobGloria wrote:
Diesel engines aren't designed for fast getaway. They like to cruise down the road at a steady pace. If you boost the power to make for fast starts you will more than likely make the fuel mileage worse.

And murder the transmission.

[Mr_Mark1]

I will preface my statement that I'm not a mechanic or gear-head, but I read a lot on different threads. One thing that is said often is when increasing horsepower, you increase HEAT.

Sometime reinventing the wheel is costly and can lead to other problems. I just wanted to point that out as Mr. and Mrs. LGC have a 14 yr. old motorhome.

When purchasing our motorhome, I was concerned about a 500 hp engine 'pushing' 56,000 lbs. I was told it was the rear-end gearing that gives us such a brisk start. I'm really amazed at our pulling power considering the weight and size.

Safe travels,
MM.

[BobGloria]

Diesel engines aren't designed for fast getaway. They like to cruise down the road at a steady pace. If you boost the power to make for fast starts you will more than likely make the fuel mileage worse. We have a 525 CAT in our coach and it doesn't jump away at lights but does pick up speed quickly once it gets into 2nd or 3rd gear.

[Ed_Gee]

5 Star Tuning is probably the easiest way to improve horsepower. Banks is probably the epitome of engine performance improvement with several options but is expensive.

[Loving_God_s_Co]

300 Cummins / Allison trans

[MrWizard]

Gas or diesel?

For gas engines there is the 'Banks Power Pack' system

Those that have seen too really like it

[romore]

How much do you want to spend? Horsepower costs money. A good free flowing exhaust system and air intake would be good places to start.

[Harold_Fairbank]

True dual exhaust with an H-pipe and unrestricted mufflers, cold air intake, computer tune.

Massive increase in power.

[Mr_Mark1]

Dear Ms. LGC, what engine and transmission do you have?

MM.