Well to correctly state it, electric motor have max torque(100%)at start up from zero RPM and less after that. There is nothing to create torque multiplication! Max is 100% and everything after that is less. There are drive system considerations that will have to be handled. Driving in low traction situations will need a complex computer torque management system.
Electrics should have 100% torque throughout it's RPM range...from Zero RPM to specified max RPM
As for the higher torque than spec...it depends on the controller. Good to great controllers
can over drive to attain +300% torque...but the down side is thermal and the reduced
That great controller will have regenerative braking and understand coasting to several
levels of braking. That also depends on the battery or storage device's ability to
absorb (recharge rate). Why many will have resistive disapation to suppliment the
storage device's recharge for high rates of regenerative braking
Your comments/thoughts/thinking is common and is from ICE's, gear multiplication
and hydraulic multiplication (TC). Had the same issues with the two large OEMs engineers
when consulting on the, then, next gen hybrid SUV
Terminated that contract when I realized that there were not going to use my teams
stuff and just cramming knowledge from my engineers. Mostly regenerative stuff.
Plus when their marketing folks laughed at my suggestion to put in a charge cord
as my controller system could recharge with little changes...they said their customers
don't want a charge cord....guess what...most all hybrids now come with a charge cord...
Yup...why I passed on diesel back in the late 90's reading/learning
about diesel's. Saw the power wars going head on with SMOG requirements
coming down the tracks. It is all coming true...
Wait till self ignition (dieseling...no spark plug) and stratified charge (direct
injection, but variation of what is out there now for gasser ICEs) gassers come
out for gasser towing engines
It's already here for cars and just like direct injection...will make it's way
to truck engines soon
That might be short lived...as electric motors can do it now (more torque than
diesel and sooner in the RPM range...like +300% torque at ZERO RPM). Issue is
all in the storage IP...not there yet for towing
Plus no need for a tranny (either manual or automatic)...maybe an over drive
gear box. No gear box if weakened field is employed, but then that then reduces
torque (withing duty cycle rating...reduce duty cycle and amount of torque
in a weakened field state can be higher)
Torque management will be in the electric motor controller
An extreme minority vs the fashion statement crowd that demands 'car' attributes
Knew that when ordering my 1996 8.6K GVWR Suburban...dealers/sales
people kept on pitching the number of cup holders and ride quality.
They didn't know the difference between a 'half ton' and a '3/4 ton'
All of those salesman walked over from the 'car' side of the showroom
to service me. Had deposits at several dealerships (SUV's were a hot
item then) and when they started coming in...all half tons and they
truly did NOT know the difference, plus that the contract stated an
8,600 GVWR (I insisted that the write that)
Ordered mine from a semi-truck broker who also sold cars and light duty trucks
That salesman really knew his stuff and actually called the area whomever trying
to special order a manual for me, but they all told him not allowed.
To that PM asking why I dissed the GMT900...well just my preference. As dislike
the 1K tongue limit on such a magnificent vehicle...and gone is the truck attributes
Hidden in ride quality stuff...and yes, am on the extreme minority there too
Love all of my four vehicles. My first brand new car...a 2 seater rocket and still
have it. That one I'll keep forever. Between the 7 seat mini van, Silverado and
the Suburban...I'd keep the Suburban. Will also keep the S65 that is
on order a looong time
Again, speaking to the choir...as most do not understand the difference between
all half ton vs an 8.6K GVWR Full sized SUV
Hope you all keep yours a loooooooooong time, as there is nothing out there
except for Bryan's 1 ton full sized van and if my Sub should get totaled that
is what I'm going to replace it with
Yes, a very sad situation for the longest continuous automotive model
line/badge at over 75 years
The market ID folks no longer understand towing
chipping away at the 8.6K GVWR Sub with that very poor GMT800 receiver,
then the 1K max tongue receiver on the GMT900
I keep mine forever...did noodle the Excursion when it came out, but
it had less payload than mine...then noodled the 8.1K, but that very
poor receiver thing...
Mine used to be my daily 70-80 mile round trip commute (Silicone Valley
so dead stopped to creeping about half of that each day) and now just
my weekend/towing/etc fun vehicle. So not many miles are going to be
Like you, am stuck because of the need for the room and tow rating.
A 1 ton full sized van, but no good 4x4...Bryan's is of interest, but
not going to let go of my Sub for a long while. That was my first
choice when looking and ordered my Sub when found no OEM 4x4
Nothing wrong with keeping them and just fixing them. The GMT800 and
GMT900's seem smaller on the inside for me.
Mine is at +160,000 extremely hard miles and the day it needs or I
want to rebuild the 7.4L...it's getting the works. Headers (long tube),
cam...maybe forced induction of some sort...etc
Take care of yours and it will last...it is a TRUCK and built to work
and last (or at least from the GM800 back)
Welcome to the forum !
First decide if you believe in the OEM ratings or not
If not, then do whatever and note that you have taken the liability
and the OEM's are off the hook
If yes, then read up and this quote/diagram should help you 'see' the
whole picture of the ratings system(s). Really easy and simple math
once you understand both how the system works and some of the terms
which are to be followed or are meaningless
Then figure out which advisor believes in the ratings or not to base
your decision using their advice
http://img.photobucket.com/albums/v77/bentoy/Towing/howmuchcanItowdiagramB4.jpg width=640 howmuchcanitow howmuchshoulditow
That your wheels won't instantly fall off if over loaded...just sooner
and that your PERFORMANCE will be reduced
Above quote from this thread: Trailer Weight Calculations & Load Estimator Utility...five pages of discussion
The OEMs use 'stripper' models (curb or dry) to derive the ratings
The only way to know for sure where you are in reference to those
ratings is to actually go out and weigh the whole setup axle by axle
So many folks have a hard time understanding and/or accepting that
the OEMs do this and in reality the OEMs have no choice because of
the buyers who only look at the brochure numbers/ratings. To decide
their purchase based on the 'King of the Hill' comparison numbers
No one knows you and how you pack. From nothing to taking the kitchen
sink plus the dog... :B
So you can do the simple math using the GVWR's (the rated maximum of
both the TV and the trailer). Some will argue never will reach GVWR
to some who will advise it's okay to exceed because they designed in
'safety factor'....which is true...but how much and will you reach that?
Keith, I do know more, but both my eng short hand and why I don't come
by as often...
FWIW...my consulting team worked on the, then, next gen hybrid and the
automatic redesign. We were called in late, as they were having thermal problems
Found that they wanted the controller inside the automatic and use the
ATF as coolant :E
Talked shop with several of their tranny guys and did cover T/H. So,
yes understand 'their' genesis for the T/H function (warranty) and
most of the stuff it does (PSI is only one aspect). They did NOT want
to have two electric motors, but space was at a premium...boy is that
automatic going to be pricey to fix...
Ordered the 'F60' option when ordering my Suburban. For those who
don't know...the F60 option is the snow plow prep package and begets
the 1 ton front torsion bars, etc.
Since my rear diff assembly is 'almost' identical to the 1 ton dually
of that year (the difference is in the brakes...cylinders are larger
bore and the MC has larger bores, proportioning valve is different, etc)
Tongue on cheek call mine a K3500...
Turtle is an old salt and knows his stuff. He has more patience than
I, as I'd rather have been able to order mine with manual 5 speed.
What bothers him is the kind of stuff I dislike about automatics
and the 'new' bells and whistles for the non-manual owners...
Best way to settle this for 'your' setup is go out and actually weigh it without
anything loaded in/on/etc. Just as you got it from the dealer
Then compare it to the brochure or sticker/label 'dry' weight
'Dry' is the 'TV curb weight' version for a trailer....AKA stripper model that
is not sold, but used for certification testing
An example is for the 'curb' for my TV and is an official Calif State DMV certificate
that gets it's info from the VIN# and that then gets info from the OEM (GM)
provided to the state of Calif DMV against that VIN#
Note that it lists my 'as tested' vehicle weight, but in fact it is the listed
'curb' weight. My TV's curb is listed in several other places as 5,400, 5,600
and 5,800 pounds. In this case it is listed at 5,250 pounds
Most 'half ton' Suburbans with a small block will weigh more than
5,250 pounds WITHOUT any cargo/people/etc. Mine has a big block,
4x4 and the highest option package orderable
I've weighed it with me (180), toolbox (+200) and misc stuff (about 50) at the
local garden scales (county weights and measure certification sticker
on the scale) at around 7,200 pounds (it's been a while and can't
remember the exact number)
so minus the approx 400 lbs would have it 'around' 6,800 pounds vs the CA EMV/GM
listed of 5,250 pounds. That is 'around' or 'approx' 1,550 pounds over the 'curb'
To get mine down the the official 'curb' would have to unbolt and either toss
or replace with 'standard' equipment:
Big Block replaced with a small block
Replace the automatic with a manual tranny
Toss the 4x4
Highest option level (toss the 2nd and 3rd row seats, rugs, power windows,
power seats, power door locks, roof rack, ceiling console, insulation package,
and a big ETC, as who knows what is on the stripper model)
The Tow/Haul button/function was invented for those who do NOT know HOW2 manage
their automatics by manually shifting....to do down a gear or more...to hold a
gear longer, etc
Pretty soon the OEMs will increase the cost/price and complexity to manage folks
who will NOT and/or do NOT understand HOW2 use the Tow/Haul button.
My guess is electrical. Strain gauge and/or when the trailer plug has
a connection. The TV will then automatically switch on the Tow/Haul function for
the Automatic transmission
I like it after read a couple of threads on this. I'll be seriously looking
at the Blue Ox for my next setup
Love how they designed that nifty chain latch assemblyThat latch assembly also shortens the chain's moveable range to increase the anti sway resistanceProof of that was in another thread where someone said their bars bent turning tight. Reaffirms #2See how they have forged the bar ends to additionally add to the anti sway control.
Other than someone hauling these units for a lving,from the manufacturer to the dealer, Then, then empty or dry weight is a joke....No person who has purchased a TT or a 5er to camp in WILL NOT tow it empty or dry. I see post after post after post when people are wanting to know if their truck "will tow it", and they give a dry weight or empty weight number and even go as far as using the "dry pin weight" when talking about a 5er...It's a bit deceptive....one would think that one would understand that number means the truck is empty of water, propane, clothese, outdoor chairs, dry good's, pots pans and on and on and on....the EMPTY or DRY weight number is useless IF that number is what the consumer is looking at and trying if they can tow it...the "empty" and/or "dry" weight is useless when trying to match a tow vehicle to the unit
Anyone purchasing a TT or 5er to tow SHOULD use the 5er's GVW when trying to figure out "if their truck and tow it"....not the empty weight...same with pin weight...dry pin weight is yet another joke that people fall into looking at....Common sense would dictate that when one goes camping, they'll be loading up their TT or 5er when they drive off....Again, please do yourselves a favor and use the rv's GVWR when trying to figure out what to tow it with. Until one has purchased a brand new unit and transferred everything from one unit to another, I believe most would be surprised at just how much "stuff" they store in their 5er, especially if they have children....just my .02 and worth much less than that....Common sense seems to have taken a back seat at times when trying to match a tow vehicle to a TT or a 5er and one uses "dry weight" or "empty weight" as the number they're figuring on. It's a number that is almost irrelevant to what one is trying to figure out..
Agree and is the safest way
Try looking at it from the OEM's point of view selling to the public
That public is hell bent on mine's bigger than yours, so the various
bragging points are marketing's demographics
'Dry' is the stripper and so many think since it can't be ordered, nor
sold, it does NOT exist. Ditto for the 'curb' on TV's
These 'Ratings' (the 'R' in the acronyms) are real and part of the OEMs
contract to their buyers.
In order to have the highest CCC/Payload/etc, they take the GVWR and
strip it down to the bare essentials. That provides the maximum bragging
rights and marketing positioning
The Fed's are coming and hope sooner than later. Betcha the OEMs will
continue to figure out workarounds, as their customers will continue
to demand or buy via bragging rights of the biggest, fastest, etc
Oh, on the 'standard' stuff that folks 'think' are included because it
is part of the 'package' or that is the only way you can order one...well
they most likely used the stripper devoid of all those options during
their certification testing...
Also, am sure there are good OEMs out there who do it right or more
correctly, but haven't found one yet...
A good thread !
Braking is more important to me than 'go' and am a boy racer who loves 'go'
Integrated controller, so ask if it is MC hydraulic sensed or brake pedal
Both my TV's (the 1996 Sub and the 1980 Silverado) have performance
brakes and can out stop most or lots of cars. So they need to have the
trailer lead in braking by lots...
My P3 and system is setup to lead by lots and even leads MC Hydraulic
Can modulate the trailer brakes via the TV's brake pedal and NEVER
have the TV's brakes come on.
#1 What condition is your trailer brake harness in? Betcha stock and
minimally sized wire gauge...plus marginal connectors to even stake
type connectors (that is what I call them...they do NOT cut the wire,
but poke a split tab that pushes the wire insulation outa the way to
then touch the wire)
#2 What type of friction material does the trailer shoes have? Condition
of the drums? Self adjusters usually don't, so I manually adjust
often during a trip. Normally at each pit or fuel stop
#3 Integrated, so not a DIY and the worrisome (to me) bleeding of the
sensor line, but MC Hydraulic sensors do leak and go bad. Or you have
an air bubble between the sensor and the MC piston
#4 Does your integrated controller also sense the brake pedal? If so,
that might be able to be readjusted to provide more lead
#5 Trailer grease on the shoes or drum. Even a greasy finger when
working on it can make a difference
#6 Trailer brake magnets...they do wear out and/or get rusty and
not provide full force
I can't think of anything that would be gained by decomposing the sources of the various limits on our TV's. The manufacturers have an incentive to make these ratings as high as possible, since truck purchasers are looking for the best payload and tow capacities. I worry that the margins of error may be made too small in order to accommodate the marketing department.
I don't agree with what you're saying here. Sure I get manufactures are free to establish their own benchmark for tow ratings, and therefore free to inflate numbers as they desire.
Back to my earlier posts on this...decide either you believe in the
OEM's ratings or not. Also note that GCWR has an 'R' in there
If no, then do whatever, but know that you have taken the OEMs (yes
more than one) off the hook and taken that liability
If yes, then learn how that system works and goes to that picture posted
Both liability and warranty are baked into all ratings
Hopefully this will soon change starting in 2015 as Toyota, Ford, GM, and Chrysler begin aligning with the SAE International Standard J2807 (Performance Requirements for Determining Tow-Vehicle Gross Combination Weight Rating and Trailer Weight Rating).
But to your point above, deciphering your axle or total vehicle gross weight rating is very much a combination of the underlying component parts that make up that rating, with the lowest common denominator limiting the rating. Take my little 1/2 ton pickup for example:
Rear Axle unit w/E-locker and 3.73 = 4800#
Rear Springs = 4050#
Rear wheels (20" 6-lug) = 4050# (2025ea)
Rear Tires 275/55R20 (P-scorpion) = 4806# (2403ea)
The axle housing itself can support up to 4800# gross weight however the limiting components are the springs and wheels which hold back the rear GAWR to 4050# as a result.
Over analysis to lose the over all picture....a rat hole and need to
go back up to 60,000 feet to see the system
We will NEVER know which is the weak link dictating these ratings.
All we can do is guess
On that, a weak link can be a shorter MTBF that the EOM lowers to gain
more 'RATING'. They knowingly do that all the time and for folks out
here think pulled out of the sky...
My rear GAWR is 6,000 and is the OEM rating (GM), but GM purchases this
AAM rates this assembly they ship to GM at 10,000 GAWR.
Some see that the OEM tires are approx 3,000 rated each...so they assume
that is the limiting factor...maybe...maybe not...again we'll never
that kind of thinking would have them go out and purchase 5,000 lb
rated tires...but wait...how about the wheels? How about the brakes?
How about the springs? How about the bolts for those springs? How
about the frame hanger? How about the frame itself? and a BIG ETC...
Again, decide if you believe in the OEMs ratings or not...then the
liability issues when you re-engineer. Yes it is a multiple faceted
'SYSTEM' comprised of many systems and components
My ratings and should be same/similar to that Sub you are looking at
CURB............5,400 - 6,000
Actual.............7,200...with me (180), toolbox (+200), misc (apprx..50-75)
MTWR......10,000.....meaningless unless that Sub actual weight is 6,000
My door label has been posted, but not at home and using iPad...so search isn't working
Here is a typical GMT800 'half ton' Suburban's door label
Here is the 2000 (GMT800) GM GCWR matrix chart
That is a GMT400, just like my 1996 K3500 7.4L
Made my own harness initially, but sold the boat/trailer and the new
owner insisted on the harness and modified receiver. So my receiver is
his old one from his GMT400 5.7L 3/4 ton
Here is the link to my HOW2 use the OEM harness and the modifications
I made to personalize it
1996 Suburban tow harness
The 4.1 and makes more of a difference with the small block...note
that going over sized tires will effectively reduce numerically that
GMT400's do have issues, but none that can't be fixed or adjusted
Brakes are not very good, but mine are very good after my modifications.
Mainly to lube the front caliper slide tubes/bolts and keep that in
good order. The front brake hoses do need changing at around 100K miles
Mine are stainless braided. Other is that the frame clips rust to
pinch off the hose. So make sure the frame clips are not rusty.
Rear brake self adjusters don't, so expect to manually adjust them
often. Mine need adjusting every 2K miles or so
Have performance (race) friction materials, but note that they don't
have much braking when cold. Can out stop most vehicles out there on
dry and good pavement
Assume the previous owner(s) have changed out the intake manifold
gaskets. Very poor design and the new ones very good. Felpro is my
fav, but the OEM is also good
This era small block does do well with intake and exhaust mods
I do NOT advise tuners, as they consume margins.
I've made my own cold, ram air intake and other simple mods and is
spelled out on this thread: Chevy 454 maintenance
Blind acceptance of any OEM design or specification....
I question anything and everything, but do accept MOST of them
Like the Andersen WD Hitch.
I think an innovative and elegant architecture, but very poor execution there of.
So understand keeping an open mind on things and also know my limits and strengths
Key is that YOU are willing to see the other side and MAYBE change or adjust your position
Take that thread whether to grease or not...goes to the thread where I decided to leave for a while
Same topic, but know most won't get that either
The torque wrench used to tighten that ball to OEM spec (in some cases...+400 ft/lbs) is in the three feet range....if the trailer coupler needs grease and the general advice
here is to NOT grease...has the potential of a +20 feet lever arm loosening the ball
Some even say to ignore the OEM torque spec and just tighten it REAL GOOD...or some such
Worse if folks listened to advice that they can lightly tighten and then glue the nut on
How long will it take a bit of grit between the ball and coupler to further loosen it ?
Or this discussion where some folks chimed in to say OEM has dialed in margin...even 2X or more...so okay to go over is the potential assumption that some might take...as there is extra margin....or to ignore the RATINGS because there is margin...or that they have for decades or thousands of miles with no issue
Again, congratulate you for an open mind
That the designers design to the worse case scenario their specification dictates
That worse day out there when Mr Murphy crosses your or the other guys path
Most advice are for the good days out there when Mr Murphy isn't around
That is where the bean counter management comes in...twice
They decide what the specification shall be....then they approve the final design
AFTER the engineering management/team approves
http://img.photobucket.com/albums/v77/bentoy/Towing/howmuchcanItowdiagramB4.jpg width=640 howmuchcanitow howmuchshoulditow
That your wheels won't instantly fall off if over loaded...just sooner
and that your PERFORMANCE will be reduced
So to the root of these last 4 posts; this utility is very simply based on the math and nothing more. It's a tool where a member of the towing community can hit the CAT scale, plug in their raw data against the corresponding manufacture specifications, and walk away with an understanding of where they fall in comparison. There is no 20% safety margin or subject of towing best practices involved in this tool. That responsibility falls to the user based on their level of comfort. For example this tool will tell you if you're at 99% of your GVWR, but does that mean it's a good idea to be at the bleeding edge of your vehicle limits? That's a question only the user can answer based on their comfort level....
Repeat that those trying to figure this out, first decide if they
believe in 'ratings' or not
If no, then do whatever, but know that they have taken the OEM(s) off
the liability hook (mostly...our court system is whacky)
If yes, then understand how any ratings system works. That the weakest
link dictates the over all rating of the 'system'
Here is a diagram of how the vehicle ratings systems looks like in
Note that the diagram shows how2 using the actual weights...then
compare the results to the 'ratings'
http://img.photobucket.com/albums/v77/bentoy/Towing/howmuchcanItowdiagramB4.jpg wideth=600howmuchcanitow howmuchshoulditow