Need advice on negotiating mountain passes

[RedBird1]

We are 17 days into our first ever RV adventure renting a 2011 Tiffin Allegro Open Road '35. We're about to go through Wolfs Creek pass in CO. Not towing. I'm vaguely familiar with shifting down and using the tow button to slow speed without excessive braking and have heard the Ford V-10 eNgine operates best on the incline at max torque of 3400rpm. We plan to takeit real slow and stop orpull over frequently to allow others to pass Any advice you experienced mountain drivers may have would be most welcome. Thanks in advance

[450Donn]

Do not go down any faster than you went up. Keep off the brakes. If you have to use the brakes apply them firmly get your speed down fast and then get off the brakes. Riding the brakes will over heat them and end your trip real fast.

[Cousin Ed]

When I have to use the brakes to maintain my desired speed, I always slow down 10 - 15 MPH so it will give me a long time before I have to apply them again. Your plan is great!

[RickO]

Great advice on the breaking. Sounds like you've done your homework already and know that, while climbing, you want to down shift to keep your RPM in the proper range and watch your temp gauge continuously.

Coming down is the bigger challenge IMHO.

Best of luck and stay safe.

Rick

[njs42]

It will not take long for you to get to "feeling" the road and your MH. Be conservative and anticipate. With a little practice you will get to know the gears best suited for a 6% or 7% up and down, then just choose according to experience.

Pay attention to 18 wheelers they drive these road often and manage them pretty well. Gearing and weight is different but I learned a lot watching them. Sometimes when I am driving I find one that has the correct pace for me and I just sit back and follow.

Up hill find the right gear and stay in it, look far ahead and anticipate moves from other slow moving vehicles, check your mirrors and see whats going on behind.

When cresting, prepare ahead for downhill, don't rush over the top because you naturally gain speed, gear down on top, then ease over (relate speed to conditions of course) correct your speed in advance of gaining too much MPH or REV's. Look far ahead and prepare for the road, corners, slower vehicles etc.

Going up is easy just find a gear where you climb steadily at a reasonable speed not overtaxing your rig. You will hear it, feel it complain, most have what we call a "sweet spot" pay attention. Mine likes 3700 RPM up hill so do I. I choose the gearing that gets me there and hold, no matter the speed. Relax.

Downhill is the art form, use the gears and spare the brakes as much as possible, but brake when called for, don't let your vehicle get ahead of you.

Since you cannot create a burst of speed or a rapid slow down then you must think farther ahead. It is nice to sit up high where you can see what is going on.

[Mike Canter]

Pessman, it is not max torque that is going to get you up a steep grade it is max horsepower. Torque is great for accelaration but not going to help climbing at a constant speed. Look in your book on the V-10 and find what the RPM is for max horsepower. If I remember correctly it is around 4250rpm. So if climbing a 6% or greater grade then downshift you tranny to maintain the mph you are comfortable with the motor at 4250 rpm. 3400 rpm is way to low and will cause you to lose momentum and maybe overheat. At 4250 RPM you are really going to hear the motor because you are sitting on top of it. Don't let it bother you and get used to it.

[Sky_Boss]

Here is an interesting passage from:

HPandTorque

So, getting back to the question asked at the beginning of this discussion: If you had to choose between two different engines, and the largest vehicle performance concern you had was getting the best hill-climbing speed, would you rather have an engine with a higher torque spec or a higher HP spec? Think of an answer before reading further.

If you answer "higher torque", you might need to review the material again. The peak torque spec is just an arbitrary data value that you could change easily with a simple gear, without affecting usable engine output. The HP spec cannot be similarly manipulated. If you answered "higher HP", you've realized that only usable HP is going to keep you going up the hill without slowly coming to a halt. And you've probably realized that engines and transmissions are designed to work together to select the gear that will give you the most usable HP when you floor the accelerator pedal, regardless of vehicle speed. In this case, your engine RPM should be at the point yielding maximum rear-wheel HP, which has nothing to do with the RPM point yielding maximum engine torque at the crankshaft. A good 6-speed transmission will allow enough adjustment of gear ratio to keep the engine within a hundred RPM or so of the point of peak engine HP.

[Sky_Boss]

Here is a reference from my previous post. It is more directed at diesel engines with some interesting information on the affect of the cooling fan for DPs.

http://www.catrvclub.org/PDF_Docs/Un...nding_Perf.pdf

After reading about the cooling fan's parasitic drain of HP...makes some sense why an initial climbing speed can drop off as the same grade of climb continues but engine temp climbs.

[pagosajoe]

We live in Pagosa Springs at the bottom of Wolf Creek Pass. Do be cautious. The advice given above is very good. Gear down, don't over use the brakes.

It's a very good road, with passing lanes except for a few narrow spots. Watch for rocks in the road that have fallen from the side of the mountain. (Watch for mountain goats too!)

There is a pullout at the top of the pass, as well as at the ski resort just below the top of the pass - stop and check things out, let your engine cool if you need to before heading down the mountain. Coming up the pass from the east is also a steep climb.

Lastly, there are two runaway truck ramps - the second one at the bottom of the pass is hard to hit if you need it. And we certainly hope that you don't!

Don't mean to scare you, but an 18 wheeler lost control and flipped over just a few days ago. You'll see the paint he was carrying that spilled all over the road.

All that said, it's a beautiful trip, and the scenery is fantastic!!

[Mike Canter]

Don the thuddriver that is a great post. I have 1650 ft lbs of torque at 1200 rpm and 525 HP at 1800 rpm. If I sat my engine on 1200 rpm to climb a steep grade it would slowly come to a standstill. If I set it on 1800 rpm for max HP then I am climbing all day with no problems. If it gets real steep like 10-11% grade then I downshift and keep the motor at 1800 rpm. I might be going slow but I am going to make it to the top,

I have hydraulically operated fan that runs off a separate hydraulic pump that is attached to the Allison tranny with a special PTO. I don't have much parasitic drain off the motor because of this

[S2kskibum]

I drive mountain passesall the time in my 94 Bounder 34J here in Colorado - heading west to Utah/Nevada, West Vail, or Grand County - Berthoud Pass. Never a single issue, just don't be in a hurry! Never have seen the temperature gauge move more than half a letter. Enjoy Colorado, and don't sweat the driving.

[pagosajoe]

To add one more thought on Wolf Creek Pass - after you go by the last runaway truck ramp heading west, you'll come to a hairpin curve - that's the tightest turn on the pass - be careful there especially. Passengers will enjoy the fantastic view overlooking the valley floor nearly 1000 feet below.

Wolf Creek Pass is a bit unique in mountain passes in Colorado which is why it's legendary in the C.W. McCall epic song:

C.W. MCCALL - WOLF CREEK PASS LYRICS

[Lindsay Richards]

There is a book called The Mountain Book. It has an East and Western edition. It list ever grade for every major highway in the US and we use it for planning purposes. My wife hates steep grades and this is a good way to avoid them. Camping World has them for about $12 or so.

[Mike Canter]

That would be a great book because most of the time when we hit steep grades my wife is always in the drivers seat. This means we have to pull over on a grade and switch drivers and get 45000 lbs rolling again which takes a lot to build up speed.