DIY Electric Car Forums banner

1 - 20 of 21 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter #1
Hi,
=

I was talking with Chip about EV's that are over the gross vehicle weight w=
here a cop wouldn't approve a friend's Ev at inspection since he said the c=
ar can't be operated over the GVW. Are *any* conversions under the gross v=
ehicle weight rating? I don't know of any car I've converted when adding 7=
00-1000 lbs is still under the GVW. I normally remove the rear pressure re=
gulator which helps, get the springs beefed up in St. Mary's Kansas (or equ=
iv) *but* the stopping distance and handling are always worse than when it =
was a gas vehicle. Even most electric trucks I've seen, S-10 & Rangers wit=
h 65 x 20 =3D 1300lbs are over their GVW. Hmm
=

Have a renewable energy day,
Mark in Roanoke, VA
_________________________________________________________________
Boo!Scare away worms, viruses and so much more! Try Windows Live OneCare!
http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=3Dwl_hotma=
ilnews
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #2
My Jeep CJ-7 project is well under on paper. So far, body, frame and axles
are about 2000 lbs, GVW is 4500.

----- Original Message -----
From: "Mark Hanson" <[email protected]>
To: <[email protected]>
Sent: Tuesday, October 16, 2007 7:53 AM
Subject: [EVDL] More Than Gross Vehicle Weight



Hi,

I was talking with Chip about EV's that are over the gross vehicle weight
where a cop wouldn't approve a friend's Ev at inspection since he said the
car can't be operated over the GVW. Are *any* conversions under the gross
vehicle weight rating? I don't know of any car I've converted when adding
700-1000 lbs is still under the GVW. I normally remove the rear pressure
regulator which helps, get the springs beefed up in St. Mary's Kansas (or
equiv) *but* the stopping distance and handling are always worse than when
it was a gas vehicle. Even most electric trucks I've seen, S-10 & Rangers
with 65 x 20 = 1300lbs are over their GVW. Hmm

Have a renewable energy day,
Mark in Roanoke, VA
_________________________________________________________________
Boo! Scare away worms, viruses and so much more! Try Windows Live OneCare!
http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=wl_hotmailnews
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #3
On 16 Oct 2007 at 8:53, Mark Hanson wrote:

> Are *any* conversions under the gross vehicle
> weight rating?

Solectria designed the Force to stay under GVWR. With one model - I think
it was a long-range car fitted with NiMH modules - they had to cut down or
block part of the back seat, making it a 3-place car, in order to stay under
GVWR.

> Even most electric trucks I've seen, S-10 & Rangers with 65 x 20 =
> 1300lbs are over their GVW.

It seems to me that payloads on small pickup trucks used to be much larger
through the 1970s. If you could find one of these venerables in good shape,
it might give you a better shot at making a safe, legal lead sled.

And of course there are purpose-built EVs in the wings - Jerry's Freedom and
Lee's Sunrise - if I'm not mistaken both are designed to carry a substantial
mass of batteries.

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
EVDL Information: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Note: mail sent to "evpost" or "etpost" addresses will not
reach me. To send a private message, please obtain my
email address from the webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =


_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #4
If you reinforce the frame by adding frame members, installing heavy duty
suspension units, spindles, axles, larger brakes, wheels with the correct
load rating, tires at the correct load rating.

You can build a new frame and suspension from scratch and put any body on
it. You have to present all the specifications of these items to the
vehicle inspector. You can either down load the weight limits of steel
beams or channel or get them from a steel yard. The suspensions and related
items will have the maximum load limits for that item.

My El Camino had a Gross weight limit of 5500 lbs. Change the wheels from a
1800 lb rating to 3500 lb rating, tires to a 2600 lb rating, the axils from
1.25 inch diameter to 3 inch diameter using 3 inch roller bearings with
inner and outer races design for 4000 lbs each. Front spindles change to
4000 lb rating, suspension systems change from 1800 lb to 3500 lb rating and
reinforce the frame with sections of 6 inch I beams with additional 6 inch
by 4 inch 1/4 inch thick square tubing cross members that are welded to the
frame that was also box with 1/4 inch steel plates.

This info was only in one 2 inch thick folder which I had a stack of these
folders on this vehicle about 2 foot high. The vehicle inspector eyes glaze
over and sign it off and got out of there.

Roland


----- Original Message -----
From: "Mark Hanson" <[email protected]>
To: <[email protected]>
Sent: Tuesday, October 16, 2007 6:53 AM
Subject: [EVDL] More Than Gross Vehicle Weight



Hi,

I was talking with Chip about EV's that are over the gross vehicle weight
where a cop wouldn't approve a friend's Ev at inspection since he said the
car can't be operated over the GVW. Are *any* conversions under the gross
vehicle weight rating? I don't know of any car I've converted when adding
700-1000 lbs is still under the GVW. I normally remove the rear pressure
regulator which helps, get the springs beefed up in St. Mary's Kansas (or
equiv) *but* the stopping distance and handling are always worse than when
it was a gas vehicle. Even most electric trucks I've seen, S-10 & Rangers
with 65 x 20 = 1300lbs are over their GVW. Hmm

Have a renewable energy day,
Mark in Roanoke, VA
_________________________________________________________________
Boo! Scare away worms, viruses and so much more! Try Windows Live OneCare!
http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=wl_hotmailnews
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #5
Mark,

The below message is regarding a Fiat 500 conversion in Italy. Same curb w=
eight as original, but better weight distribution, Lithium batteries had a =
lot to do with this.

Alan

http://www.youtube.com/watch?v=3Dp1W757i_cD4
http://www.austinev.org/evalbum/1347

Marco eat your heart out. Orginal weight and 50/50 weight distribution wit=
h a 60 mile range. With such a small pack this car using a better charger =
would be capable of sub one hour charge times. I don't have Marcos email. =
I think he might be interested in seeing this one. Lawrence Rhodes....


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behal=
f Of Mark Hanson
Sent: Tuesday, October 16, 2007 5:54 AM
To: [email protected]
Subject: [EVDL] More Than Gross Vehicle Weight


Hi,
=

I was talking with Chip about EV's that are over the gross vehicle weight w=
here a cop wouldn't approve a friend's Ev at inspection since he said the c=
ar can't be operated over the GVW. Are *any* conversions under the gross v=
ehicle weight rating? I don't know of any car I've converted when adding 7=
00-1000 lbs is still under the GVW. I normally remove the rear pressure re=
gulator which helps, get the springs beefed up in St. Mary's Kansas (or equ=
iv) *but* the stopping distance and handling are always worse than when it =
was a gas vehicle. Even most electric trucks I've seen, S-10 & Rangers wit=
h 65 x 20 =3D 1300lbs are over their GVW. Hmm
=

Have a renewable energy day,
Mark in Roanoke, VA
_________________________________________________________________
Boo!Scare away worms, viruses and so much more! Try Windows Live OneCare!
http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=3Dwl_hotma=
ilnews
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #6
Mark,
It is posible. Im just 100lbs over stock weight with
1/3 tank of gas and 600lbs. below gross weight. This
is with 1300lbs. of lead !
http://www.austinev.org/evalbum/736
Jeff McCabe






--- Mark Hanson <[email protected]> wrote:

> =

> Hi,
> =

> I was talking with Chip about EV's that are over the
> gross vehicle weight where a cop wouldn't approve a
> friend's Ev at inspection since he said the car
> can't be operated over the GVW. Are *any*
> conversions under the gross vehicle weight rating? =

> I don't know of any car I've converted when adding
> 700-1000 lbs is still under the GVW. I normally
> remove the rear pressure regulator which helps, get
> the springs beefed up in St. Mary's Kansas (or
> equiv) *but* the stopping distance and handling are
> always worse than when it was a gas vehicle. Even
> most electric trucks I've seen, S-10 & Rangers with
> 65 x 20 =3D 1300lbs are over their GVW. Hmm
> =

> Have a renewable energy day,
> Mark in Roanoke, VA
>
_________________________________________________________________
> Boo!Scare away worms, viruses and so much more! Try
> Windows Live OneCare!
>
http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=3Dwl_hotma=
ilnews
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
> =


_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #7
From: Mark Hanson
> Are *any* conversions under the gross vehicle weight rating?

My EVs have all been under the GVWR. This is probably because I have never tried to load it full of batteries to maximize range.

For example, my 1974 Datsun pickup was rated to carry 1300 lbs, but I only had twelve 6v golf cart batteries in it (800 lbs). My LeCar was rated for 750 lbs, and I have 680 lbs of batteries.

The consequence is of course a shorter range (20-40 miles depending on speed).


--
"Excellence does not require perfection." -- Henry James
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #10
I think trucks are the easiest to accomplish this, since they normally have=
a higher GVW ratio to curb weight

My 1965 Datsun truck weighed in at 2180#.
My estimate after conversion is ~ 2900#.
Gross vehicle weight is 3963#. This is a 156V system using 12 volt AGM batt=
eries.

If your willing to accept higher cost and shorter range by using 12 volt AG=
M's, you should be able to stay under the GVW.

Most of the cars/trucks exceeding their GVW are using 6 volt flooded batter=
ies.
They will although, give you the maximum range for the lowest initial cost.

Dennis
Elsberry, MO


-----Original Message-----
From: Mark Hanson [mailto:[email protected]] =

Sent: Tuesday, October 16, 2007 7:54 AM
To: [email protected]
Subject: [EVDL] More Than Gross Vehicle Weight


Hi,
=

I was talking with Chip about EV's that are over the gross vehicle weight w=
here a cop wouldn't approve a friend's Ev at inspection since he said the c=
ar can't be operated over the GVW. Are *any* conversions under the gross v=
ehicle weight rating? I don't know of any car I've converted when adding 7=
00-1000 lbs is still under the GVW. I normally remove the rear pressure re=
gulator which helps, get the springs beefed up in St. Mary's Kansas (or equ=
iv) *but* the stopping distance and handling are always worse than when it =
was a gas vehicle. Even most electric trucks I've seen, S-10 & Rangers wit=
h 65 x 20 =3D 1300lbs are over their GVW. Hmm
=

Have a renewable energy day,
Mark in Roanoke, VA
_________________________________________________________________
Boo!Scare away worms, viruses and so much more! Try Windows Live OneCare!
http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=3Dwl_hotma=
ilnews

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #11
I figure my truck is under it's GVWR. But then, since it's a "Self
Assembled Vehicle" it doesn't have a GVWR per se.

Your friend might try going to a different inspector and having the
vehicle re-classified as whatever your state calls a home-built vehicle.

FWIW My truck carries almost 1,000 lbs of batteries with a total vehicle
weight of about 3250 lbs. A lot of small, so called "economy cars" weigh
almost that much.


> From: Mark Hanson [mailto:[email protected]]
> Sent: Tuesday, October 16, 2007 7:54 AM
> To: [email protected]
> Subject: [EVDL] More Than Gross Vehicle Weight
>
>
> Hi,
>
> I was talking with Chip about EV's that are over the gross vehicle weight
> where a cop wouldn't approve a friend's Ev at inspection since he said the
> car can't be operated over the GVW. Are *any* conversions under the gross
> vehicle weight rating? I don't know of any car I've converted when adding
> 700-1000 lbs is still under the GVW. I normally remove the rear pressure
> regulator which helps, get the springs beefed up in St. Mary's Kansas (or
> equiv) *but* the stopping distance and handling are always worse than when
> it was a gas vehicle. Even most electric trucks I've seen, S-10 & Rangers
> with 65 x 20 =3D 1300lbs are over their GVW. Hmm
>
> Have a renewable energy day,
> Mark in Roanoke, VA
> _________________________________________________________________
> Boo!Scare away worms, viruses and so much more! Try Windows Live OneCa=
re!
> http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=3Dwl_hot=
mailnews
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>


-- =

If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #12
most vehicles gvw is 800-1000 pounds above curb weight to leave room for pa=
ssengers and cargo, and then you remove probably on average 5 or 6 hundred =
pounds worth of unnecessary engine, fuel and related components, so with th=
ought and planning staying under gvw by at least the weight of one passenge=
r shouldn't be hard and it should be considered and important part of the d=
esign. Of course if you start with a 2 seat sports car there is going to be=
less room between the cub weight and the gvw to begin with, also although =
there is a tendency to start with the lightest vehicle you can find, a heav=
ier vehicle will be better designed for handling the weight of the conversi=
on AND probably has more unnecessary stuff so that after stripping the diff=
erence in weight is much less than the difference to begin with

I have read many conversion pages online where the builder skips the vacuum=
pump and the ps pump and just manhandles the car and this is not only ille=
gal but scares me as someone who shares the roads DOT has braking and steer=
ing standards that must be met for the safety of everyone

as far as a conversion that is overweight read through the DOT website, you=
can get the gvw raised on converted vehicles (usually for things like tow =
truck and ambulance conversions) by submitting the vehicle for braking test=
s and such, just remember if you haven't improved the brakes you are not go=
nna stop any better than the manufacturer did
> =

> =

> --- Mark Hanson <[email protected]> wrote:
> =

> > =

> > Hi,
> > =

> > I was talking with Chip about EV's that are over the
> > gross vehicle weight where a cop wouldn't approve a
> > friend's Ev at inspection since he said the car
> > can't be operated over the GVW. Are *any*
> > conversions under the gross vehicle weight rating? =

> > I don't know of any car I've converted when adding
> > 700-1000 lbs is still under the GVW. I normally
> > remove the rear pressure regulator which helps, get
> > the springs beefed up in St. Mary's Kansas (or
> > equiv) *but* the stopping distance and handling are
> > always worse than when it was a gas vehicle. Even
> > most electric trucks I've seen, S-10 & Rangers with
> > 65 x 20 =3D 1300lbs are over their GVW. Hmm
> > =

> > Have a renewable energy day,
> > Mark in Roanoke, VA
> >
> _________________________________________________________________
> > Boo! Scare away worms, viruses and so much more! Try
> > Windows Live OneCare!
> >
> http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=3Dwl_hot=
mailnews
> > _______________________________________________
> > For subscription options, see
> > http://lists.sjsu.edu/mailman/listinfo/ev
> > =

> =

> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev

_________________________________________________________________
Boo!Scare away worms, viruses and so much more! Try Windows Live OneCare!
http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=3Dwl_hotma=
ilnews
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #13
You can build a new frame and suspension from scratch and put any body on
it. You have to present all the specifications of these items to the
vehicle inspector. You can either down load the weight limits of steel
beams or channel or get them from a steel yard. The suspensions and related
items will have the maximum load limits for that item.


You can't do that in Canada - an individual cannot 're-GVWR' a vehicle,
regardless of modifications, springs, whatever. Only the OEM can do that,
unless you are building a ground-up vehicle. This is a recent change -
within the last five or so years. Only certain cars have 'ok' GVWR to curb
difference, but in most cases a lead conversion of a car will be short range
if you stay under the limit. A 1998 Escort, 1991 Integra, 1994 Aspire are
just a hair over 420 kg difference. Most cars are under 350 kg.

-Dale

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #14
My first 2 conversion are under the GVWR. A beach buggy with 10
Optimas is still lighter than a stock Beetle! The Rabbit Pickup had a
GVWR of 4000 lb. with a starting weight of 2000 lb. allowing 20 GC
batteries to fit without issue. Now I'm working on a '66 Datsun with
a GVWR of 2723 lb. and expect it to weigh around 2500 lb. when
complete (13 Optimas is the plan.)

Its quite possible to build under the GVWR by converting a compact
pickup with a 3/4 ton rating or building a shorter range vehicle.

Paul Gooch

Mark Hanson wrote:

> Are *any* conversions under the gross vehicle weight rating?

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #15
Paul, where did you get that 4000lb GVWR from?
My 81 rabbit pickup is 3300lb GVWR With 20
T-125's it is right at 3300lb with no one in it.
P.S. I hope you upgraded the front brakes to 11"
rotors if you want to stop quickly.

Al

--- Original Message -----
From: "Paul" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Tuesday, October 16, 2007 8:09 PM
Subject: Re: [EVDL] More Than Gross Vehicle Weight


> My first 2 conversion are under the GVWR. A beach buggy with 10
> Optimas is still lighter than a stock Beetle! The Rabbit Pickup had a
> GVWR of 4000 lb. with a starting weight of 2000 lb. allowing 20 GC
> batteries to fit without issue. Now I'm working on a '66 Datsun with
> a GVWR of 2723 lb. and expect it to weigh around 2500 lb. when
> complete (13 Optimas is the plan.)
>
> Its quite possible to build under the GVWR by converting a compact
> pickup with a 3/4 ton rating or building a shorter range vehicle.
>
> Paul Gooch
>
>
Mark Hanson wrote:
>
>> Are *any* conversions under the gross vehicle weight rating?
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #16
Al wrote:

> Paul, where did you get that 4000lb GVWR from?
> My 81 rabbit pickup is 3300lb GVWR With 20
> T-125's it is right at 3300lb with no one in it.
> P.S. I hope you upgraded the front brakes to 11"
> rotors if you want to stop quickly.

Right off the WA title and registration. Some where listed at 4000
lb. though I didn't find any difference between the 1/2 ton and 3/4
ton rated versions, except perhaps the rear springs.

I was still running the non-vented stock front rotors and never had
any issues. GTI front rotors and pads wouldn't be a bad idea. I bet a
few quick stops in a row from 60 to 0 would have caused some brake
fade (but its generally a bad idea anyway.) With 13 of the batteries
in the front of the bed (7 under the hood) the back brakes finally
did some work.

Paul Gooch

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #17
Hey Paul,
Drum brakes fade cause they expand when heated. What would cause disks to
fade?

On 10/17/07, Paul <[email protected]> wrote:
>
>
Al wrote:
>
> > Paul, where did you get that 4000lb GVWR from?
> > My 81 rabbit pickup is 3300lb GVWR With 20
> > T-125's it is right at 3300lb with no one in it.
> > P.S. I hope you upgraded the front brakes to 11"
> > rotors if you want to stop quickly.
>
> Right off the WA title and registration. Some where listed at 4000
> lb. though I didn't find any difference between the 1/2 ton and 3/4
> ton rated versions, except perhaps the rear springs.
>
> I was still running the non-vented stock front rotors and never had
> any issues. GTI front rotors and pads wouldn't be a bad idea. I bet a
> few quick stops in a row from 60 to 0 would have caused some brake
> fade (but its generally a bad idea anyway.) With 13 of the batteries
> in the front of the bed (7 under the hood) the back brakes finally
> did some work.
>
> Paul Gooch
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>



--
http://www.austinev.org/evalbum/1059
http://stormselectric.blogspot.com/
Storm
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #18
Brakes, both disk and drum, can fade because of the pads outgassing when
they get hot. High performance discs are sometimes cross drilled to let the
gasses out from between the pad and the disk surface.

Marty
----- Original Message -----
From: "storm connors" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Monday, October 22, 2007 5:49 PM
Subject: Re: [EVDL] More Than Gross Vehicle Weight


> Hey Paul,
> Drum brakes fade cause they expand when heated. What would cause disks to
> fade?
>
> On 10/17/07, Paul <[email protected]> wrote:
>>
>>
Al wrote:
>>
>> > Paul, where did you get that 4000lb GVWR from?
>> > My 81 rabbit pickup is 3300lb GVWR With 20
>> > T-125's it is right at 3300lb with no one in it.
>> > P.S. I hope you upgraded the front brakes to 11"
>> > rotors if you want to stop quickly.
>>
>> Right off the WA title and registration. Some where listed at 4000
>> lb. though I didn't find any difference between the 1/2 ton and 3/4
>> ton rated versions, except perhaps the rear springs.
>>
>> I was still running the non-vented stock front rotors and never had
>> any issues. GTI front rotors and pads wouldn't be a bad idea. I bet a
>> few quick stops in a row from 60 to 0 would have caused some brake
>> fade (but its generally a bad idea anyway.) With 13 of the batteries
>> in the front of the bed (7 under the hood) the back brakes finally
>> did some work.
>>
>> Paul Gooch
>>
>> _______________________________________________
>> For subscription options, see
>> http://lists.sjsu.edu/mailman/listinfo/ev
>>
>
>
>
> --
> http://www.austinev.org/evalbum/1059
> http://stormselectric.blogspot.com/
> Storm
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>


_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #19
Storm,

Brakes can also fade when the fluid gets very hot and bubbles are
produced in the brake system. You get a soft spongy brake pedal when
this happens and very little braking. If you have water contamination
in your brake fluid, the heat required for fade will be less and you
will have problems earlier. This is called fluid fade.

With pad fade, the heat in the drum or disk and pad or shoe does not
affect the hard feel of the brake pedal. You get decreased breaking as
mentioned below from the melting or out gassing of the pad or shoe
material. Heat, smeared binding compounds in the pad, out gassing,
causes glazing of the metal disc or drum, and much less effective
braking. I have read about a coefficient of friction curve where the
friction surfaces in the brake are less effective when under very high
temperatures. Pad fade gives you a hard brake pedal as normal, but much
less braking. Diesel trucks coming down a long grade too fast will heat
up and glaze over the brake drums. You can get the brake system so hot
on a commercial truck that the wheel hub seal fails, the oil in the hub
leaks out, and a fire is started.

Lots of heat in a disc brake can cause the disc to warp, especially if
the steel or manufacturing process was not the best. A warped brake
disc produces a very strong vibration in the affected wheel. At speed,
or under aggressive braking it can be dangerous. You may think that you
need a tire balanced, but you need to resurface the disc or install a
new one.

Alan

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Marty Hewes
Sent: Monday, October 22, 2007 3:55 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] More Than Gross Vehicle Weight

Brakes, both disk and drum, can fade because of the pads outgassing when

they get hot. High performance discs are sometimes cross drilled to let
the
gasses out from between the pad and the disk surface.

Marty
----- Original Message -----
From: "storm connors" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Monday, October 22, 2007 5:49 PM
Subject: Re: [EVDL] More Than Gross Vehicle Weight


> Hey Paul,
> Drum brakes fade cause they expand when heated. What would cause disks
to
> fade?
>
> On 10/17/07, Paul <[email protected]> wrote:
>>
>>
Al wrote:
>>
>> > Paul, where did you get that 4000lb GVWR from?
>> > My 81 rabbit pickup is 3300lb GVWR With 20
>> > T-125's it is right at 3300lb with no one in it.
>> > P.S. I hope you upgraded the front brakes to 11"
>> > rotors if you want to stop quickly.
>>
>> Right off the WA title and registration. Some where listed at 4000
>> lb. though I didn't find any difference between the 1/2 ton and 3/4
>> ton rated versions, except perhaps the rear springs.
>>
>> I was still running the non-vented stock front rotors and never had
>> any issues. GTI front rotors and pads wouldn't be a bad idea. I bet a
>> few quick stops in a row from 60 to 0 would have caused some brake
>> fade (but its generally a bad idea anyway.) With 13 of the batteries
>> in the front of the bed (7 under the hood) the back brakes finally
>> did some work.
>>
>> Paul Gooch
>>
>> _______________________________________________
>> For subscription options, see
>> http://lists.sjsu.edu/mailman/listinfo/ev
>>
>
>
>
> --
> http://www.austinev.org/evalbum/1059
> http://stormselectric.blogspot.com/
> Storm
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
>


_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #20
Thanks guys. This is quite a classroom. Lesson learned: Change the brake
fluid annually. Buy high quality pads.

On 10/22/07, Alan Brinkman <[email protected]> wrote:
>
> Storm,
>
> Brakes can also fade when the fluid gets very hot and bubbles are
> produced in the brake system. You get a soft spongy brake pedal when
> this happens and very little braking. If you have water contamination
> in your brake fluid, the heat required for fade will be less and you
> will have problems earlier. This is called fluid fade.
>
> With pad fade, the heat in the drum or disk and pad or shoe does not
> affect the hard feel of the brake pedal. You get decreased breaking as
> mentioned below from the melting or out gassing of the pad or shoe
> material. Heat, smeared binding compounds in the pad, out gassing,
> causes glazing of the metal disc or drum, and much less effective
> braking. I have read about a coefficient of friction curve where the
> friction surfaces in the brake are less effective when under very high
> temperatures. Pad fade gives you a hard brake pedal as normal, but much
> less braking. Diesel trucks coming down a long grade too fast will heat
> up and glaze over the brake drums. You can get the brake system so hot
> on a commercial truck that the wheel hub seal fails, the oil in the hub
> leaks out, and a fire is started.
>
> Lots of heat in a disc brake can cause the disc to warp, especially if
> the steel or manufacturing process was not the best. A warped brake
> disc produces a very strong vibration in the affected wheel. At speed,
> or under aggressive braking it can be dangerous. You may think that you
> need a tire balanced, but you need to resurface the disc or install a
> new one.
>
> Alan
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Marty Hewes
> Sent: Monday, October 22, 2007 3:55 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] More Than Gross Vehicle Weight
>
> Brakes, both disk and drum, can fade because of the pads outgassing when
>
> they get hot. High performance discs are sometimes cross drilled to let
> the
> gasses out from between the pad and the disk surface.
>
> Marty
> ----- Original Message -----
> From: "storm connors" <[email protected]>
> To: "Electric Vehicle Discussion List" <[email protected]>
> Sent: Monday, October 22, 2007 5:49 PM
> Subject: Re: [EVDL] More Than Gross Vehicle Weight
>
>
> > Hey Paul,
> > Drum brakes fade cause they expand when heated. What would cause disks
> to
> > fade?
> >
> > On 10/17/07, Paul <[email protected]> wrote:
> >>
> >>
Al wrote:
> >>
> >> > Paul, where did you get that 4000lb GVWR from?
> >> > My 81 rabbit pickup is 3300lb GVWR With 20
> >> > T-125's it is right at 3300lb with no one in it.
> >> > P.S. I hope you upgraded the front brakes to 11"
> >> > rotors if you want to stop quickly.
> >>
> >> Right off the WA title and registration. Some where listed at 4000
> >> lb. though I didn't find any difference between the 1/2 ton and 3/4
> >> ton rated versions, except perhaps the rear springs.
> >>
> >> I was still running the non-vented stock front rotors and never had
> >> any issues. GTI front rotors and pads wouldn't be a bad idea. I bet a
> >> few quick stops in a row from 60 to 0 would have caused some brake
> >> fade (but its generally a bad idea anyway.) With 13 of the batteries
> >> in the front of the bed (7 under the hood) the back brakes finally
> >> did some work.
> >>
> >> Paul Gooch
> >>
> >> _______________________________________________
> >> For subscription options, see
> >> http://lists.sjsu.edu/mailman/listinfo/ev
> >>
> >
> >
> >
> > --
> > http://www.austinev.org/evalbum/1059
> > http://stormselectric.blogspot.com/
> > Storm
> > _______________________________________________
> > For subscription options, see
> > http://lists.sjsu.edu/mailman/listinfo/ev
> >
> >
>
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>



--
http://www.austinev.org/evalbum/1059
http://stormselectric.blogspot.com/
Storm
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 
1 - 20 of 21 Posts
Top