Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-03-2015, 10:06 AM   #29
Rivet Master
 
ROBERTSUNRUS's Avatar

 
2005 25' Safari
Salem , Oregon
Join Date: Mar 2006
Posts: 7,269
Images: 18
Blog Entries: 51
Quote:
Originally Posted by Andrew T View Post
The last time I towed an Airstream with a V8 in the mountains was about 30 years ago everything since has been with a V6 think you will find you need the run the 3.5 about 6-800 RPM higher to get the same amount of braking from it.

The two extra gears and the lower first gear ratio will give you a better operating range and first gear will give you just as much total breaking.

Hi, Thank You; That makes sense, smaller engine = higher RPM.
__________________

__________________
Bob

2005 Safari 25-B
"Le Petit Chateau Argent"
[ Small Silver Castle ]
2000 Navigator / 2014 F-150 Eco-Boost / Equal-i-zer / P-3
YAMAHA 2400 / AIR #12144
ROBERTSUNRUS is offline   Reply With Quote
Old 01-03-2015, 10:08 AM   #30
Full time Airstreamer
 
SCOTTinNJ's Avatar
 
2014 30' FB FC Bunk
Anywhere , USA Living.Somewhere.Yonder
Join Date: Jan 2014
Posts: 1,161
V6 likely has higher rpm range anyway.
__________________

__________________
@living.somewhere.yonder | Instagram
SCOTTinNJ is offline   Reply With Quote
Old 01-03-2015, 11:14 AM   #31
Full time Airstreamer
 
SCOTTinNJ's Avatar
 
2014 30' FB FC Bunk
Anywhere , USA Living.Somewhere.Yonder
Join Date: Jan 2014
Posts: 1,161
deleted.
__________________
SCOTTinNJ is offline   Reply With Quote
Old 01-03-2015, 11:52 AM   #32
Moderator
 
DKB_SATX's Avatar

 
2017 26' Flying Cloud
1976 Argosy 28
Alamo Heights , Texas
Join Date: Aug 2006
Posts: 6,401
Images: 1
Blog Entries: 7
Quote:
Originally Posted by Dexterpix View Post
All internal combustion engines have some type of "throttle plate" you have to regulate the intake of air into the engine. More air = more fuel = more power. A diesel without a "exhaust brake" will still use the engines compression to resist acceleration. Diesel engines are a more effective engine brake because of the higher compression (2x or more than most gas engines)

Always followed a simple rule that whatever gear I needed to climb a hill was the gear I used to descend the other side. Both climbing and descending are fighting gravity, in theory the work load to maintain a given speed should be similar.
Quote:
Originally Posted by jcl View Post
All spark ignited engines have some form of throttle plate. Not true for compression ignition engines. Thus, diesels have no significant retardation effect unless fitted with an auxiliary brake such as a Jake or other design. Compression ratio doesn't enter into it as the work to compress air on the up stroke is returned on the piston down stroke.
The blanket statement that all spark-ignition engines have a throttle plate is no longer accurate, and is likely to become less generally accurate as technology moves forward. BMW's "Valvetronic" intake system has a sort of a choke plate in the intake stream but it remains fully open once the engine is running at normal temperatures and the engine manages air intake by varying the intake valve opening. I'm not sure if Fiat's "MultiAir" system even has the choke plate in the stream, but it runs in a similar fashion to the Valvetronic concept.

The even more general "all internal combustion..." statement is way off, since (as stated several times up-thread) there's no need for a throttle plate in a diesel.

Also pay heed to what "Al and Missy" had to say: do not fear downshifting, a modern automatic isn't going to shift into a gear that'll ruin the engine, it'll wait until you're going slow enough. Shift down for whatever braking the drivetrain can offer you at that moment and keep scrubbing off speed as you descend. It may be noisier than you expect (just like climbing the hill you just crested probably was if you have a NA gasoline engine like my 5.4L) but it's part of what your vehicle was designed to do.
__________________
ó David

Zero Gravitas ó 2017 Flying Cloud 26U | Il Progetto ó 1976 Argosy 28 Center Bath | WBCCI# 15566

He has all of the virtues I dislike and none of the vices I admire. ó Sir Winston Churchill
DKB_SATX is offline   Reply With Quote
Old 01-03-2015, 12:22 PM   #33
jcl
Rivet Master
 
Currently Looking...
Vancouver , British Columbia
Join Date: Oct 2012
Posts: 1,049
Quote:
Originally Posted by DKB_SATX View Post
The blanket statement that all spark-ignition engines have a throttle plate is no longer accurate, and is likely to become less generally accurate as technology moves forward. BMW's "Valvetronic" intake system has a sort of a choke plate in the intake stream but it remains fully open once the engine is running at normal temperatures and the engine manages air intake by varying the intake valve opening. I'm not sure if Fiat's "MultiAir" system even has the choke plate in the stream, but it runs in a similar fashion to the Valvetronic concept.
Appreciate the correction. I actually have a BMW with Valvetronic, and have towed small trailers with it, but thought we were getting a little deep into motorhead territory.

Add Toyota's Valvematic system to the list.

Jeff
__________________
jcl is offline   Reply With Quote
Old 01-07-2015, 10:52 AM   #34
Rivet Master
 
1981 31' Excella II
New Market , Alabama
Join Date: Sep 2011
Posts: 5,648
Well if they electronically control the valves there is no reason they can't build in some sort of engine brake into the software. I try to stay at least 10 yrs old to avoid lemons in the R and D process, let fools rush in.

Perry
__________________
perryg114 is offline   Reply With Quote
Old 01-07-2015, 12:48 PM   #35
jcl
Rivet Master
 
Currently Looking...
Vancouver , British Columbia
Join Date: Oct 2012
Posts: 1,049
Quote:
Originally Posted by perryg114 View Post
Well if they electronically control the valves there is no reason they can't build in some sort of engine brake into the software. I try to stay at least 10 yrs old to avoid lemons in the R and D process, let fools rush in.

Perry
If you are referring to Valvetronic, you can safely jump into the pool with us early adopters then. It has been in production since 2001.

I do understand your sentiment. With technology-heavy vehicles like BMWs I avoid the first production year of new models.
__________________
jcl is offline   Reply With Quote
Old 01-10-2015, 12:57 PM   #36
4 Rivet Member
 
Hodum's Avatar
 
1995 34' Excella
Corinth , Mississippi
Join Date: Dec 2010
Posts: 304
I am certainly glad that i read this thread from front to back. However most of it was far too technical for me, but I have a F 250 with an exhaust brake that worked like a charm on the Blue Ridge parkway. It is up one and down one then all over again. I don't understand the process, but with a thirty four foot Classic loaded to 10,300 lbs. it told me all I needed to know.
__________________
Why settle for anything less?
1995 34ft Classic Excella 1000
2012 Kings Ranch F-250 FX-4, 6.7 diesel, 6 speed auto trans.
TAC # MS-8
Hodum is offline   Reply With Quote
Old 01-11-2015, 05:09 PM   #37
Rivet Master
 
tjdonahoe's Avatar
 
2013 31' Classic
billings , Montana
Join Date: Feb 2010
Posts: 1,844
Too technical for me too ,and I have a dodge 2500 with a 6.7 with an exhaust brake and 6 speed automatic and it has towed our as's 50000 with no problems and I also don't worry what the weights are, we just go....no worries..big is sometimes better.....
__________________
tjdonahoe is offline   Reply With Quote
Old 01-11-2015, 06:44 PM   #38
Rivet Master
 
Aerowood's Avatar

 
1971 21' Globetrotter
Arvada , Colorado
Join Date: May 2006
Posts: 2,841
I don't even think about it anymore, downshifting in the Colorado mountains is just what you do, trailer or no trailer. When going up the passes I don't pay any attention to the speedometer and drive the tachometer. I couldn't tell you how many times trucks and trailers and even cars wipe themselves out by not downshifting going down the mountain passes. I think some people rely to much on technology instead of paying attention to the environment them. Safety is not just throwing a switch on the dash.
Aerowood is offline   Reply With Quote
Old 01-14-2015, 08:50 PM   #39
Rivet Master
 
tjdonahoe's Avatar
 
2013 31' Classic
billings , Montana
Join Date: Feb 2010
Posts: 1,844
You are correct, you slow down on the down side,I have been to Ouray up and down the million dollar highway and over to Silverton and Durango.It sure does feel good with the exhaust brake on, you seldom have to use the service brakes..my big truck gets 550000 miles between brake replacement.you should try a tv with an exhaust brake, you might like it....
__________________
tjdonahoe is offline   Reply With Quote
Old 01-20-2015, 09:17 PM   #40
4 Rivet Member

 
2003 31' Classic
Terra Alta , West Virginia
Join Date: Jan 2015
Posts: 266
I have a similar tow vehicle. A 96 7.3 F 250 SC. I have not investigated too far but my son had one that used the factory butterfly in the exhaust that is the warm up method from the factory. The device was some sort of programmer/software that was plug and play. It closed off the exhaust and locked the converter. Worked well and cost was reasonable. If I learn more I will let you know. The old 7.3 is hard to beat-towing or not. I am at 160K and with good care, plan on another 160K.
__________________

__________________
wvstreamer is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Losing engine elec. engine dies while driving ccgartman Airstream Motorhome Forums 4 12-10-2011 09:46 AM
Diesel Engine Braking guy99 Mechanics Corner - Engines, Transmission & More... 5 02-10-2006 02:42 PM
Toad Saturn braking questions pbnjsellers General Motorhome Topics 5 06-02-2005 08:49 AM
Braking systems question? zduke4x General Motorhome Topics 7 03-29-2004 09:05 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 12:17 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.