|
08-18-2018, 12:37 PM
|
#1
|
Member
Jayco Owners Club
Join Date: Dec 2017
Posts: 39
|
Going down steep hill
Might be a dumb question. How do u reduce RPM’S when going down a steep hill.?
|
|
|
|
Join the #1 RV Forum Today - It's Totally Free!
iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!
You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!
|
08-18-2018, 12:42 PM
|
#2
|
Senior Member
Join Date: Nov 2017
Location: Citra, Florida
Posts: 1,396
|
Quote:
Originally Posted by Fawndale
Might be a dumb question. How do u reduce RPM’S when going down a steep hill.?
|
If you can start in low gear then it is best to do so. If you find yourself going a bit too fast then step on the brake firmly and watch the rpms then downshift when the rpms drop, one gear at a time. If you have an Allison transmission then just step on the brake and the trans will down shift automatically. Never ride the brake and NEVER put it in neutral. I was surprised to see that some drivers actually do this.
__________________
Good Luck and keep us posted please. "Q"
1999 Newmar, Mountain Aire 3768, V-10, CAI, Headers.
"Spending our kids inheritance one trip at a time"
|
|
|
08-18-2018, 01:06 PM
|
#3
|
Senior Member
Join Date: May 2017
Location: Metamora, MI
Posts: 5,518
|
If you have a DP with a jake / engine brake, use that instead of the wheel brakes.
I just got an electric foot pedal to augment the dash switch to apply the jake during twisty roads. The jake / allison will downshift for you.
Best is to put your RV in your signature so we can be more helpful.
BTW, when one downshifts ideally before the downhill gets steep, the RPMs go UP, not down. In any given gear, as you slow MPH the RPM will then also drop.
If you have a Gas RV, downshift manually before the hill gets steep and allow the engine / transmission to do most of the decel. Use the brakes when needed but try not to continually ride the brakes down the length of the hill so they have a chance to cool off inbetween applications.
The key is to not let the RV get going too fast. Keep it managed the whole way from the "It's going to get Steep" sign, to the base of the hill.
__________________
2002 Newmar Mountain Aire Limited 4370 w/ Spartan K2 and Cummins 500hp
ASE Master Certified (a long.....time ago...)
|
|
|
08-18-2018, 06:20 PM
|
#4
|
Senior Member
Thor Owners Club Ford Super Duty Owner
Join Date: Jul 2011
Posts: 3,788
|
Starting out at a low speed is you best approach but if you have to brake to get the speed/RPM down intermittent hard braking is better than light to moderate long braking. You need to be proactive and down shift early at the top of the hill. Hung the right lane, activate the four way flashers and keep your speed manageable. Engine braking by down shifting works, be it a gas or diesel engine.
I've found on my gas coach that I can easily hold 35 mph in second gear on 8% grades with the RPM up around 4200 RPM. The electronic rev limiter for the Ford V10 is around 5250 RPM so I'm well within safe engine limits. If I find the coach picking up speed too fast or I have to brake too often I'll drop to first gear.
__________________
2006 Hurricane 31D built on a 2006 Ford F53
|
|
|
08-18-2018, 09:19 PM
|
#5
|
Senior Member
Join Date: Aug 2001
Location: North America somewhere
Posts: 30,592
|
Quote:
Originally Posted by Sweetbriar
Starting out at a low speed is you best approach but if you have to brake to get the speed/RPM down intermittent hard braking is better than light to moderate long braking. You need to be proactive and down shift early at the top of the hill. Hung the right lane, activate the four way flashers and keep your speed manageable. Engine braking by down shifting works, be it a gas or diesel engine.
I've found on my gas coach that I can easily hold 35 mph in second gear on 8% grades with the RPM up around 4200 RPM. The electronic rev limiter for the Ford V10 is around 5250 RPM so I'm well within safe engine limits. If I find the coach picking up speed too fast or I have to brake too often I'll drop to first gear.
|
Sound advice! Fawndale has a Winnebago Vista, 27'.
__________________
2000 Winnebago Ultimate Freedom USQ40JD , ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG 11B5MX,Infantry retired;Good Sam Life member,FMCA. " My fellow Americans, ask not what your country can do for you, ask what you can do for your country. John F. Kennedy
|
|
|
08-19-2018, 05:11 AM
|
#6
|
Senior Member
Tiffin Owners Club
Join Date: Jul 2016
Location: Where we park it!
Posts: 13,145
|
Lots of good advice. Just remember...NEVER ride the brakes but rather intermittent "hard" breaking. Riding the breaks will make them fail and have the fire extinguisher ready at the bottom of the hill (I have seen brake fires at the bottom the hill before)
__________________
momdoc
2018 Tiffin Allegro RED 37PA
2020 JEEP Trailhawk
|
|
|
08-19-2018, 05:12 AM
|
#7
|
Senior Member
Tiffin Owners Club
Join Date: Jul 2016
Location: Where we park it!
Posts: 13,145
|
I should add.. NOT my coach on fire
__________________
momdoc
2018 Tiffin Allegro RED 37PA
2020 JEEP Trailhawk
|
|
|
08-19-2018, 06:49 AM
|
#8
|
Registered User
Ford Super Duty Owner
Join Date: Nov 2014
Location: NW Ohio
Posts: 7,114
|
Quote:
Might be a dumb question. How do u reduce RPM’S when going down a steep hill.?
|
On my gasser, V10 and 4 spd transmission... When descending a long steep grade, I use the engine as a brake. The higher the rpms, the more braking action, but I like to keep the rpms below about 4,500.
In order to do this, I'll slow down, and manually downshift. If the MH continues to pick up speed, I'll slow down more and downshift to a lower gear..
Usually long descents I can usually do 45 mph, 2nd gear, 4,000 rpm. I've descended a few grades in 1st gear and 25 mph (4,000 rpm)
|
|
|
08-19-2018, 10:28 AM
|
#9
|
Moderator Emeritus
Join Date: Jan 2000
Location: West Palm Beach, FL. USA
Posts: 27,519
|
Actually, you don't want to reduce RPMs in most cases. You want the engine to help with speed reduction, whether its a gas engine or a diesel with exhaust or engine brake. In either case higher rpms means more braking and you actually downshift to keep the rpms up higher.
If your engine is in danger of exceeding it safe rpm limit, it will probably upshift all by itself, but you could manually up shift if you want. But then you will need to use the brake pedal more, and that's probably not a good thing.
__________________
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL
|
|
|
08-19-2018, 05:10 PM
|
#10
|
Junior Member
Winnebago Owners Club
Join Date: Sep 2012
Posts: 15
|
My 2010 Vista, 27' gas V10 has a button on the shifter called 'Tow'. Press that and the transmission pretty much keeps the speed constant down hill. Seldom have to brake.
__________________
Paul and Sandy Rybak, Topton, NC 2010 Winnebago Vista, 26P
|
|
|
08-19-2018, 05:15 PM
|
#11
|
Senior Member
Fleetwood Owners Club Ford Super Duty Owner
Join Date: Jun 2012
Location: SoCal
Posts: 15,749
|
Stab braking. As your speed picks up apply the brakes hard to scrub of about 10mph - as you gain speed again - repeat. Don't ride the brakes - you will overheat them.
__________________
Vince and Susan
2011 Tiffin Phaeton 40QTH (Cummins ISC/Freightliner)
Flat towing a modified 2005 Jeep (Rubicon Wrangler)
Previously a 2002 Fleetwood Pace Arrow 37A and a 1995 Safari Trek 2830.
|
|
|
08-19-2018, 05:22 PM
|
#12
|
Senior Member
Join Date: Sep 2012
Posts: 8,055
|
When you brake on a twisty hill do it on the straight sections. You want the wheels to track the turn so better with the speed already down and the brakes off. On the straight sections tracking is not so much of a problem as you just keep going straight.
|
|
|
08-19-2018, 05:56 PM
|
#13
|
Senior Member
Join Date: Jan 2018
Location: UT
Posts: 1,244
|
I don't know why you want to reduce RPMs going down hill. Your question isn't very clear. However, the advice given is good. I live near mountains and travel on many a steep grade. I see out of towners ride their brakes down the mountain passes and smell the burning brakes and occasionally see wheels on fire (or entire vehicles). DON"T RIDE YOUR BRAKES! Give them a rest to cool in between applications as has been said. They get very hot.
Use the engine exhaust brake if you have a DP, it works great and really slows the coach without using service brakes. On a gasser, Down shift to use the gas engine to slow the coach (this will increase RPM though which is opposite of your question). For V10 motorhomes have a tow haul mode button on the end of the shifter that will indeed downshift and slow the motorhome as you tap the brakes.
__________________
Ed
2023 Geneva 28VA
Solar and LiFePO4, 2018 Jeep Grand Cherokee Toad
|
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|