EV Digest 6414
Topics covered in this issue include:
1) Re: Brake Pressure Multiplier?
by "David Roden" <[EMAIL PROTECTED]>
2) RE: White Zombie History
by Mike Willmon <[EMAIL PROTECTED]>
3) RE: Brake Pressure Multiplier?
by Cor van de Water <[EMAIL PROTECTED]>
4) Re: Brake Pressure Multiplier?
by Nick <[EMAIL PROTECTED]>
5) Re: Brake Pressure Multiplier?
by "Peter Gabrielsson" <[EMAIL PROTECTED]>
6) Re: noob help
by lyle sloan <[EMAIL PROTECTED]>
7) Re: Looking for a message in the archive and I can't find it
by Matthew Milliron <[EMAIL PROTECTED]>
8) Loud Hybrid Legislation (was: Re: Chain Noise Re: Personal Electric
Transport)
by Doug Weathers <[EMAIL PROTECTED]>
9) Re: aero dynamics
by Doug Weathers <[EMAIL PROTECTED]>
10) Re: aero dynamics
by "jerryd" <[EMAIL PROTECTED]>
11) EV's on Boston Legal , Re: Free Publicity
by "jerryd" <[EMAIL PROTECTED]>
12) Re: Brake Pressure Multiplier?
by Rich Long <[EMAIL PROTECTED]>
13) Re: Speaking of Hybrids
by Frank John <[EMAIL PROTECTED]>
14) Re: Chain Noise Re: Personal Electric Transport
by Frank John <[EMAIL PROTECTED]>
15) Re: Brake Pressure Multiplier?
by Frank John <[EMAIL PROTECTED]>
16) Re: Chain Noise Re: Personal Electric Transport
by Mike Chancey <[EMAIL PROTECTED]>
17) RE: Cost to drive a EV
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
18) Re: Brake Pressure Multiplier?
by Jeff Shanab <[EMAIL PROTECTED]>
19) Re: Brake Pressure Multiplier -brake drag
by "Phil Marino" <[EMAIL PROTECTED]>
20) Re: aero dynamics
by "Peter VanDerWal" <[EMAIL PROTECTED]>
21) Re: Brake Pressure Multiplier?
by "Peter VanDerWal" <[EMAIL PROTECTED]>
22) Car and Driver EV Racing Article Debute Delayed
by John Wayland <[EMAIL PROTECTED]>
23) Re: HV 3Ph AC to get round 9Ah NiMH limit?
by Martin Klingensmith <[EMAIL PROTECTED]>
24) what does unsprung mass or weight mean?
by "Jonathan Perret" <[EMAIL PROTECTED]>
25) Re: White Zombie History
by John Wayland <[EMAIL PROTECTED]>
26) Re: Brake Pressure Multiplier?
by "Peter VanDerWal" <[EMAIL PROTECTED]>
27) Re: what does unsprung mass or weight mean?
by "Peter VanDerWal" <[EMAIL PROTECTED]>
28) Re: Brake Pressure Multiplier?
by "Roland Wiench" <[EMAIL PROTECTED]>
--- Begin Message ---
On 13 Feb 2007 at 0:00, Lee Hart wrote:
> How would people feel if I used drum brakes on the Sunrise kit car?
For some reason, I'm thinking of the Citicar - it started out with aircraft
disc brakes in front, but gave them up in favor of drums all round.
David Roden - Akron, Ohio, USA
EV List Administrator
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--- Begin Message ---
Tim,
I've got my eye on the Curie 9-Plus "Race Case" for $392
http://www.currieenterprises.com/cestore/gearcases.aspx#94028
The local junk yard has a heavy wall 9" housing with the 31 spline axles
hanging out of it for $80.
I would like to have known if it had the nodular iron "N" case in it, but it
has since been scavenged. No matter though, I'd much
rather build up my own case.
I see you guys have been all up and down the gear ratios in the Zombie and
finally settled on 4.11. Any thought of raising up
slightly to a 3.89 or so? I'm wondering if you hit the 4.11 and a good
compromise for the torque on launch of the Siamese 8's.
If you had a bit more torque from a pair of WarP 9's do you think a 3.89 gear
would be an acceptable match to get a little more
top end speed?
Something else I didn't see is if the Zombie is running the HEPI assembly or a
Potbox? I like the HEPI assembly in my truck and
wonder how the throttle response differs. Maybe Otmar can comment on which one
give the more aggressive response.
Thanks for the blood, sweat, and tears (and wasted plasma) by those who have
worked on the Zombie to give us such a good model of
excellence.
It won't be too long before you guys will have to travel to Alaska Raceway Park
to defend your titles (or take them back) from the
muy pronto Pinto :-)
Mike,
Anchorage, Ak.
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Behalf Of Tim Brehm
> Sent: Tuesday, February 13, 2007 8:02 PM
> To: ev@listproc.sjsu.edu
> Subject: Re: White Zombie History
>
>
> Hello Mike, this post is regarding the first 9" housing in White Zombie,
> since John has disappeared from the list : )
> I believe John purchased the complete rearend from somebodies project V8
> Chevy LUV. The housing did have the smaller
> bearings and 28 spline axles. The previous owner had it narrowed and splined.
> The carrier was also about two inches to
> the right making drive line clearances very tight, as far as I know John
> didn't have to do do any machine work, he just
> bolted it in and later added a spool. I know John will correct me if I'm
> wrong on that.
> The new rearend is a much better setup with bigger bearings, Detroit
> locker and 31 spline Dutchman axles, Now all
> we need is a stronger carrier to keep from cracking the pinion support !
>
--- End Message ---
--- Begin Message ---
Lee,
1.Drum brakes on the Sunrise is likely a very good idea,
as I cannot imagine someone racing it (the main reason
for disk brakes) and without power assist, but having
a low weight overall, drum brakes are a very good
choice, generally good to maintain all by ourself and
with either auto-adjust (ratchet on adjust screw) or
easy reachable manual adjust, should work very reliably.
Only issue I once had with a drum brake was when I tried
to back out of my driveway in freezing weather after I
parked the night before with wet brakes (it rained the
day before - this was in The Netherlands).
It took a bit of careful rocking the car back and forth
to break the frost and free the drum, so I could use
the car (with care, because the street was frozen).
I'd be happy to buy a Sunshine some day, drum brakes all
around! (Others can feel free to upgrade to disks and
vacuum assist)
Cor.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lee Hart
Sent: Tuesday, February 13, 2007 8:31 PM
To: ev@listproc.sjsu.edu
Subject: Re: Brake Pressure Multiplier?
From: Nick
> I know many cars - Volvos come to mind - have multiple pistons in each
> caliper. In these set-ups the caliper is fixed and each pad has one or
> more pistons to put pressure on it. I would think that by eliminating
> the sliding caliper, that would eliminate the possibility of those
> surfaces seizing, and the multiple pistons with a rubber o-ring on
> each might retract more overall than a single o-ring for the entire
caliper.
> I know the added complexity of these systems can lead to other
> problems, but like anything mechanical, maintenance is critical.
The Volvo is the one car I've heard of that does this. Are there others?
Does anyone know if the Volvo system does in fact reduce dragging brakes?
I suspect that brakes drag because car companies haven't bothered to design
ones that don't drag. It's cheaper to build that way.
The GM EV1 had front disk brakes. I wonder how they were designed? It's
probably one of the rare vehicles where someone actually thought about the
problem, and may have tried to eliminate it.
How would people feel if I used drum brakes on the Sunrise kit car?
1. Great idea! Eliminates dragging brakes, and probably cheaper too.
2. Horrible idea! No one would even consider not having disk brakes nowdays.
--
Lee Hart
--- End Message ---
--- Begin Message ---
I have only worked on these kinds of calipers on the Volvo 240 series,
but I have seen them on some sports cars, like Porsches and Corvettes.
The Volvo calipers are made by ATE and Girling (depending on front or
rear axle and model year). I have been driving vehicles with four-wheel
disc brakes for years, and others with drum brakes, and I would much
prefer disc brakes over drum.
Lee Hart wrote:
From: Nick
I know many cars - Volvos come to mind - have multiple pistons in each
caliper. In these set-ups the caliper is fixed and each pad has one or
more pistons to put pressure on it. I would think that by eliminating
the sliding caliper, that would eliminate the possibility of those
surfaces seizing, and the multiple pistons with a rubber o-ring on each
might retract more overall than a single o-ring for the entire caliper.
I know the added complexity of these systems can lead to other problems,
but like anything mechanical, maintenance is critical.
The Volvo is the one car I've heard of that does this. Are there others? Does
anyone know if the Volvo system does in fact reduce dragging brakes?
I suspect that brakes drag because car companies haven't bothered to design
ones that don't drag. It's cheaper to build that way.
The GM EV1 had front disk brakes. I wonder how they were designed? It's
probably one of the rare vehicles where someone actually thought about the
problem, and may have tried to eliminate it.
How would people feel if I used drum brakes on the Sunrise kit car?
1. Great idea! Eliminates dragging brakes, and probably cheaper too.
2. Horrible idea! No one would even consider not having disk brakes nowdays.
--
Lee Hart
--- End Message ---
--- Begin Message ---
The EV1 had a electro hydraulic disc brakes in addition to regen, the
brakes were indeed designed not to drag. Some info can be gleamed from
this PDF
http://www.thejaffes.org/rory/ev1/ev1.pdf
The GM EV1 had front disk brakes. I wonder how they were designed? It's
probably one of the rare vehicles where someone actually thought about the
problem, and may have tried to eliminate it.
How would people feel if I used drum brakes on the Sunrise kit car?
1. Great idea! Eliminates dragging brakes, and probably cheaper too.
2. Horrible idea! No one would even consider not having disk brakes nowdays.
--
Lee Hart
--
www.electric-lemon.com
--- End Message ---
--- Begin Message ---
If you look through the photo album and the links of
the individual builders, they have done a fair amount
of documentation on their builds.
http://www.austinev.org/evalbum/type/MTCY And there is
one guy in the blogs of
http://www.electricmotorcycles.net that is building an
el ninja off of Bidwell's plans.
Specifically, if you want good reviews of the
Bidwell's el ninja or el chopper plans or where to
purchase them look at http://www.21wheels.com/ or
http://www.megawattmotorworks.com
--- Jay wrote:
> Has anyone read through the el ninja documentation?
> I have only just become interested in all this in
> the last 2 days so im trying to suck up all the
> information I can. I was thinking of building
> something really small first. However I do work in
> the electrical industry, so I do have some idea of
> whats going on. Anyone have any hints because I
> have been looking around the net and no one seems to
> be posting plans or a good break down on how they
> are building their vehicles. I have thus far only
> found 2 main pages they are
> http://jerryrig.com/convert/ and
> http://www.austinev.org/evalbum/build most of the
> others just talk how good they are and how smart
> they are, but no plans or anything described in
> detail. Anything would be very helpful
>
> Thanks
>
_________________________________________________________________
> Live Search: Better results, fast
> http://get.live.com/search/overview
>
>
____________________________________________________________________________________
TV dinner still cooling?
Check out "Tonight's Picks" on Yahoo! TV.
http://tv.yahoo.com/
--- End Message ---
--- Begin Message ---
On Tue, 13 Feb 2007 03:27:12 -0800 (PST), you wrote:
>I am looking for the message that Lee wrote describing his battery shunts.
Here's a pictorial step by step
http://controller.junkymagi.com/Zener_Regs.pdf
R. Matt Milliron
1981 Jet Electrica
http://www.austinev.org/evalbum/702
My daughter named it, "Pikachu". It's yellow and black,
electric and contains Japanese parts, so I went with it.
--- End Message ---
--- Begin Message ---
On Feb 13, 2007, at 9:36 PM, Kip C. Anderson wrote:
I swear I'm not making this up, but I can't find any reference to it
now and don't recall the source:.
Wall Street Journal, via Salon.
<http://online.wsj.com/public/article/SB117133115592406662
-4gKiXEZVH0RXATvUvpkVpLUsbx8_20080213.html?mod=tff_main_tff_top>
or the tiny version:
<http://tinyurl.com/33qqsz>
I read just the other day that a blind advocacy group was actually
attempting to get some legislation into play that would require
vehicles to make a minimal amount of noise.
From the article:
"The National Federation of the Blind, an advocacy group, says all
hybrid vehicles should emit a sound while turned on and is calling on
the auto industry to make changes. The group says the sound should be
loud enough to be heard over the din of other ambient noise."
So as noisy hybrids become more prevalent, the "din" gets louder, the
volume knob on the hybrids must be turned up, and voila! we have a
vicious circle of noise. Eventually the din drowns out everything else
and the blind people might as well be deaf, too. This is just dumb,
IMHO.
Hey, maybe you can't hear the hybrid because it's next to the city bus
or the garbage truck or the honkytonk bar. How about legislation that
makes everything else quieter i.e. stricter noise pollution laws?
Perhaps somebody can debunk this. I'd rather it not come to be.
It hasn't happened yet. Hopefully it won't. Remember the bill that
tried to ban box knives after 9/11? And if it does, hopefully it will
be written to only apply to hybrids, which will make EVs look better.
--
Doug Weathers
Las Cruces, NM, USA
http://www.gdunge.com/
--- End Message ---
--- Begin Message ---
On Feb 13, 2007, at 7:27 PM, Lee Hart wrote:
I think it would help. You have a Bradley GT as I recall, which is
fairly well streamlined on top. So streamlining the bottom would
definitely help.
Bradley GTs are based on the Beetle chassis, which is already pretty
streamlined underneath. You could probably stand to block off the
underside of the engine compartment - you no longer need the airflow
there to cool the ICE.
Or maybe not - aerodynamics are not necessarily intuitive. Ask Jerry
Dycus.
Victor has details of the belly pan he put on his Honda CRX. Great web
site, Victor!
<http://www.metricmind.com/ac_honda/pan.htm>
--
Doug Weathers
Las Cruces, NM, USA
http://www.gdunge.com/
--- End Message ---
--- Begin Message ---
Hi Doug and All,
----- Original Message Follows -----
From: Doug Weathers <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Subject: Re: aero dynamics
Date: Wed, 14 Feb 2007 02:05:35 -0700
>On Feb 13, 2007, at 7:27 PM, Lee Hart wrote:
>
>> I think it would help. You have a Bradley GT as I recall,
>> which is fairly well streamlined on top. So streamlining
>> the bottom would definitely help.
>
>Bradley GTs are based on the Beetle chassis, which is
>already pretty streamlined underneath. You could probably
>stand to block off the underside of the engine compartment
>- you no longer need the airflow there to cool the ICE.
While a VW chassis is much better, it can usually be
helped. Aero is funny sometimes a a little thing can change
a large area. And since it's rather cheap to do, give it a
try in controlled conditions, ie no wind, similar temps,
same road, same speed to see if it has the desired effect.
Or do coast down tests to see power required before and
after. You'll have to ask others for that technic details.
It would probably reduce snow drag too since a Bradley
GT is so low if you drive in it.
Jerry Dycus
>
>Or maybe not - aerodynamics are not necessarily intuitive.
>Ask Jerry Dycus.
>
>Victor has details of the belly pan he put on his Honda
>CRX. Great web site, Victor!
>
><http://www.metricmind.com/ac_honda/pan.htm>
>
>--
>Doug Weathers
>Las Cruces, NM, USA
>http://www.gdunge.com/
>
--- End Message ---
--- Begin Message ---
Hi Sean and All,
----- Original Message Follows -----
From: "Sean Korb" <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Subject: Free Publicity
Date: Tue, 13 Feb 2007 23:03:36 -0500
>I'm addicted to the Shatner-Spader show Boston Legal. In
>the closing argument, Spader exclaims:
I like the show but as a 4 am early morning person
I don't get to watch much. But I was up watching our 10pm
news which goes to sports late when I switched around to see
if anything interesting was on and just caught this below,
he was very good speaking it while going on about alt fuels.
Apparently Denny? started making biodiesel from
lipsuction wastes and was arrested for not properly
desposing of medical waste!! Another great but wierd story
line they are known for.
>
>"--Electricity, which we don't use simply because...
>
>I've forgotten; why don't' we have electric cars?
>
>Did we get rid of them because they're the most efficient?
>
>I bet it's because: those who actually drove them claimed
>to love them."
>
>
>Nice.
Also at the end sitting with Denny, he ased 'Who
killed the electric car, the oil companies?' Apparently a
writer or actor there saw WKTEC ;^D
Jerry Dycus
>
>--
>Sean Korb [EMAIL PROTECTED] http://www.spkorb.org
>'65, '68 Mustangs, '68 Cougar, '78 R100/7, '71 Pantera
>#1382 "The more you drive, the less intelligent you get"
>--Miller "Computers are useless. They can only give you
>answers." -P. Picasso
>
--- End Message ---
--- Begin Message ---
On Tue, 2007-02-13 at 20:31 -0800, Lee Hart wrote:
> How would people feel if I used drum brakes on the Sunrise kit car?
>
> 1. Great idea! Eliminates dragging brakes, and probably cheaper too.
>
> 2. Horrible idea! No one would even consider not having disk brakes nowdays.
>
I'd like to assemble one of your kits and I vote #1.
--- End Message ---
--- Begin Message ---
Lee, that sounds like a good test - the only way to really know is to try it.
I hope you post your results.
thanks
----- Original Message ----
From: Lee Hart <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Sent: Tuesday, February 13, 2007 2:16:50 PM
Subject: Re: Speaking of Hybrids
thomas ward wrote [lots more good advice]:
Thanks again, Thomas. I'm interested in trying your idea to use a
composite tube and epoxy to connect the cut ends of the axles. If it
works, it could be a better solution than new custom axles ($300+ each)
or the machining required to put new splines on the cut end (the
opposite end's CV joint doesn't come off; which complicates things).
Here's my EE's naive take on this ME problem.
A composite torque tube would be wound like a toilet paper tube; with
fibers at a 45 deg. angle, 2 or more layers spiraling in opposite
directions.
The adhesive to attach it to the steel would be challenging. The steel
shaft would "wind up" under torque, so the composite tube would need to
have the same torque stiffness, or the adhesive joint between them would
"peel away" from one end to the other.
It would probably be easier to use a steel tube, since it could be more
easily matched to the stiffness of the existing steel axle.
I don't know what we'd use for the adhesive between the two. I imagine
the auto industry has inspired dozens of candidates, but adhesives are
not my specialty.
So, my thought is to do some testing. Buy some 3/8" long extensions for
a socket wrench; they should be hardened similar to the axle. Measure
their stress-strain (what torque for what deflection) to failure. Cut
one, weld it, and test again. Cut one, glue it with a steel tube, and
test again. Also try brazing it with a steel tube, and epoxying it with
a composite fiberglass tube. See what the results are!
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
____________________________________________________________________________________
Bored stiff? Loosen up...
Download and play hundreds of games for free on Yahoo! Games.
http://games.yahoo.com/games/front
--- End Message ---
--- Begin Message ---
I recall reading the same thing (not where I read it though).
----- Original Message ----
From: Kip C. Anderson <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Sent: Tuesday, February 13, 2007 11:36:43 PM
Subject: Re: Chain Noise Re: Personal Electric Transport
I swear I'm not making this up, but I can't find any reference to it now and
don't recall the source:.
I read just the other day that a blind advocacy group was actually
attempting to get some legislation into play that would require vehicles to
make a minimal amount of noise.
Perhaps somebody can debunk this. I'd rather it not come to be.
And I believe that there is still one state that has or had until a
recently, a law requiring a warning flag waver in front of a vehicle driven
by a woman.
- Kip
----- Original Message -----
From: "David Roden" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, February 13, 2007 8:14 PM
Subject: Re: Chain Noise Re: Personal Electric Transport
> On 13 Feb 2007 at 7:02, Kip C. Anderson wrote:
>
>> I would not be surprised if a noise making device of low volume becomes
>> mandatory on hybrids and electrics in the future.
>
> Good grief. We're trying to reduce noise pollution with EVs, not
> introduce
> new forms of it.
>
> This reminds me a bit of the infamous laws passed in the early years of
> vehicular travel, requiring that a person walk in front of an automobile
> holding a lantern to warn of its approach. Such laws are well meaning,
> but
> in the end they're really prompted by fear of change.
>
> EVs are quiet. That's their nature, and it's a good thing. It also means
> that we, as their drivers, have to take all the greater responsibility for
> pedestrians' well being, be they sighted or no.
>
>
> David Roden - Akron, Ohio, USA
> EV List Administrator
____________________________________________________________________________________
Don't pick lemons.
See all the new 2007 cars at Yahoo! Autos.
http://autos.yahoo.com/new_cars.html
--- End Message ---
--- Begin Message ---
Lee: what is estimated final weight? The only "real" way to tell is to build
one and test, then compare to similar offerings. If 60-0 performance is poor
then it'd be hard to justify.
----- Original Message ----
From: Rich Long <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Sent: Wednesday, February 14, 2007 6:12:31 AM
Subject: Re: Brake Pressure Multiplier?
On Tue, 2007-02-13 at 20:31 -0800, Lee Hart wrote:
> How would people feel if I used drum brakes on the Sunrise kit car?
>
> 1. Great idea! Eliminates dragging brakes, and probably cheaper too.
>
> 2. Horrible idea! No one would even consider not having disk brakes nowdays.
>
I'd like to assemble one of your kits and I vote #1.
____________________________________________________________________________________
Do you Yahoo!?
Everyone is raving about the all-new Yahoo! Mail beta.
http://new.mail.yahoo.com
--- End Message ---
--- Begin Message ---
This subject came up a few years back on the EVDL. Somebody had a
link to a test done by or for the government I think. They tested
about 20 cars for low speed noise. There was an EV included in the
test, I believe it was an EV-1. It wasn't the quietest vehicle in
the test. That honor went to an Infiniti if I recall
correctly. Shall we ban quiet gas cars too?
Didn't the EV-1 have a gentle pedestrian horn as well as a conventional one?
Thanks,
Mike Chancey,
'88 Civic EV
Kansas City, Missouri
EV Photo Album at: http://evalbum.com
My Electric Car at: http://www.geocities.com/electric_honda
Mid-America EAA chapter at: http://maeaa.org
Join the EV List at: http://www.madkatz.com/ev/evlist.html
In medio stat virtus - Virtue is in the moderate, not the extreme
position. (Horace)
--- End Message ---
--- Begin Message ---
Also, when the batteries charge and discharge since they are chemically
different and their internal resistance is not the same they will react
differently. One will always take a charge faster and so it will cook
while the other catches up. If the weaker doesn't get the full charge
before the charger cuts off it will go deeper than the other or the
stronger battery will charge it up and equalize costing power. With
regulators across the pair you will still have the same problem. The
regulator will not cut the current off to the stronger battery so the
weaker can get more charge. Believe me - there will always be a weaker
and a stronger battery in a buddy pair. As the batteries age the
difference will become greater and eventually the buddy pair will kill
both batteries. I would really recommend separating the buddy pairs
into strings of series batteries that can be connected in parallel
during use or charging. That way your pack won't prematurely kill
itself. I would hate to see your batteries die a year or so early.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of David Roden
Sent: Wednesday, February 14, 2007 0:26
To: ev@listproc.sjsu.edu
Subject: Re: Cost to drive a EV
On 13 Feb 2007 at 20:50, Ralph Merwin wrote:
> An
> islator is not required because both batteries are getting the same
> discharge and charge cycles.
I'm not so sure. If a battery develops a shorted cell, its partner will
empty itself trying to charge it. I even had this happen with two
parallel 96v strings once.
David Roden - Akron, Ohio, USA
EV List Administrator
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--- End Message ---
--- Begin Message ---
I think this device is like a jack that I have it moves fast until it
encounters resistance then the second piston moves slow and generates
the high pressure. This is needed to get the pad to the disk then
pressurize the lines, after that it is ok, indeed desirable, to have a
more travel to build pressure. this added travel is only after pressure
build so it becomes un-noticeable.
ironically BMW is advertising that their disk brakes drag with just the
right amount when wet weather is detected so that they are dry and
available for max braking when needed. Although this is a good thing,
This advertisement can be miss-interpreted.
--- End Message ---
--- Begin Message ---
The Volve 140 series actually had four pistons in each front caliper ( and
two in each rear caliper). They also had small drum brakes in the rear ( as
well as the main service disks) that were used only for parking brakes.
The redundant hydraulic systems were set up so that any hydraulic failure
would still leave you with working brakes on both front wheels and one rear
wheel.
As far as brake drag, have people measured this, and is it really a
significant source of drag?
It seems to me ( I haven't done any measurements, but I will when the
temperature here goes positive again) that, whenever I spin an unloaded
wheel - when changing tires, for example- there is not a lot of drag.
I suspect that the torque due to brake drag would be too low to measure
with a torque wrench ( at least, the ones I have).
Phil
From: Nick <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: Brake Pressure Multiplier?
Date: Tue, 13 Feb 2007 22:19:26 -0800
I have only worked on these kinds of calipers on the Volvo 240 series, but
I have seen them on some sports cars, like Porsches and Corvettes. The
Volvo calipers are made by ATE and Girling (depending on front or rear axle
and model year). I have been driving vehicles with four-wheel disc brakes
for years, and others with drum brakes, and I would much prefer disc brakes
over drum.
Lee Hart wrote:
From: Nick
I know many cars - Volvos come to mind - have multiple pistons in each
caliper. In these set-ups the caliper is fixed and each pad has one or
more pistons to put pressure on it. I would think that by eliminating the
sliding caliper, that would eliminate the possibility of those surfaces
seizing, and the multiple pistons with a rubber o-ring on each might
retract more overall than a single o-ring for the entire caliper. I know
the added complexity of these systems can lead to other problems, but
like anything mechanical, maintenance is critical.
The Volvo is the one car I've heard of that does this. Are there others?
Does anyone know if the Volvo system does in fact reduce dragging brakes?
_________________________________________________________________
Check out all that glitters with the MSN Entertainment Guide to the Academy
Awards® http://movies.msn.com/movies/oscars2007/?icid=ncoscartagline2
--- End Message ---
--- Begin Message ---
> Or maybe not - aerodynamics are not necessarily intuitive. Ask Jerry
> Dycus.
Im confused, are you serious or poking fun at Jerry?
Because Jerry claims that he DOES intuitively know aerodynamics, that is
how he can state with authority what the Cd of his various vehicles is
without having to take measurements or perform calculations.
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
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wish with the message. By posting the message you agree that your long
legalistic signature is void.
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--- Begin Message ---
> The GM EV1 had front disk brakes. I wonder how they were designed? It's
> probably one of the rare vehicles where someone actually thought about the
> problem, and may have tried to eliminate it.
I seem to recall that they redisigned the seals slightly to give a bit
more pull-back. I think they might have used the extra brake travel for
regen.
Might be worth looking into what some of the more efficient hybrids are
doing.
> How would people feel if I used drum brakes on the Sunrise kit car?
How about a compromise, drums in the back and discs in front?
1/2 the drag and all the stopping power.
--
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
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legalistic signature is void.
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--- Begin Message ---
Hello to All,
I had been assured by the editors at Car and Driver, that the
anticipated EV racing story was slated for the April issue that's about
to hit the stands in the next week or two...then I got the phone call.
For whatever reason, the story got bumped I'm now told, to the May issue
:-(
It was sad news for me, as White Zombie is returning to the Portland
Roadster show this year and will be on display at the Oregon Convention
Center March 2nd, 3rd, and 4th. With the April issue to be on the stands
at the same time, the timing 'was' perfect! There's nothing better, than
to have your car in a BIG show while at the same time, it is featured in
a major magazine.... oh well.
The good news, is that Bill Dube's exciting Killacycle is in the current
April issue of Hot Rod magazine! Congrats to Bill and the crew for their
recent success.
See Ya.....John Wayland
--- End Message ---
--- Begin Message ---
360v * 9Ah = 3.24kWh
Significantly less useful. Now maybe you could parallel the battery
strings when driving and charge the two (or 3) strings separately..
--
Martin K
brougham Baker wrote:
> I'm new to this, and haven't seen/found any mention of this elsewhere so I
> guess I must be missing something.
>
> I've seen the 9Ah artificial limit on NiMH cells and have read that they
> don't like being paralleled at all. So I was thinking, high volt system like
> about 360v (300 cell string) At 9Ah cells would give a 3240kWh pack, not a
> lot really but how about if the inverter was split so you could have one
> string per phase. Is this possible? Is it easy to mod the inverter? This
> would give a fairly useable pack of 9720kWh.
>
> I've found some 9Ah Sanyo D size Cells that will do High discharge rates
> (their pdf has graphs for over 5C discharge rate). They only have a 100% DoD
> chart that doesn't drop till 500 cycles but no charts for lower DoD. A 3
> string pack of 300 cells per string would weigh 160 kg for unpacked cells.
>
> Each cell is 34mm in diameter and 59.3mm tall- for 900 cells I make this 0.2
> cu ft in size (that seems far too small.
>
> I haven't been able to get a good price though- one small volume supplier
> I've found would want £10,728 (~21k USD) so a moot point really.
>
> Brougham
>
> "I'm sick and tired of hearing that 'health and safety' is stopping people
> doing worthwhile and enjoyable things. If you're using health and safety to
> stop everyday activities, get a life and let others get on with theirs."
> Bill Callaghan (Health and Safety Commission chair)
>
>
--- End Message ---
--- Begin Message ---
Hi,
I have a basic mechanical question:
in discussions about direct drive electric motors it's often mentioned
that one of the design problems (or drawbacks) to this approach
is that the motor (presents) an unsprung mass (or weight) (to the wheel?)
can someone explain what this refers to / what it means and potential
work-arounds / solutions?
I'm interested in pursuing front wheel direct drive
I asked a friend of mine who is a mechanical engineer
(and BTW a self-styled genius) and he wasn't familiar with the term.
thanks,
Jonathan
--- End Message ---
--- Begin Message ---
Hello to All,
Thanks for this post Dennis. I'm glad you and everyone else who's
reported on stumbling into the new link, seems to like it. It's been a
lot of work, believe me! There's a lot more stuff to put up, especially
in the more recent year sections, so I hope my list friends will check
in every once in a while to see the newest pictures and additions. I
work on it nightly and a lot on the weekends.
I've wanted to do this for some time, but the soon-to-be-released Car
and Driver magazine article is what's really prompted me to get it done.
With over 10 million readers and with the Plasma Boy web page address
clearly placed in the middle of the piece for all to see, the number of
hits on the site will be very large. I want all those new to hi pro EVs
to be able to get up to speed (pun intended), and I feel a history of
the car is a great way to accomplish this.
Plea for pictures...it's hard to believe, but I'm having a hard time
finding pictures of the Kostov motor under the Zombie's hood. It's
really odd, as I've found rare pictures from the mid eighties when the
car was a stock econocar gas machine, pictures of when I had it set up
as a lowered street import with a 120+hp 10,400 rpm built 1200cc four
banger and an autocross capable suspension system, pictures of it when
it was entered in sound-off competitions, and all other kinds of stuff
up through the mid 90's that I didn't remember having. That 11 inch
motor was in there from '97 through 2000, and yet, I cannot dig up any
more under-hood pictures than the two not-so-clear installation pictures
I have at the '97 page :-( At all the Woodburn EVents during this
period, there were lots of folks with cameras, so I know 'somebody' out
there must have some great photos we could use. Anyone?
All photos of any version of the car, whether recent or from back years,
would be greatly appreciated and can only help make the 'White Zombie
History' better. Not all pictures received will make it to the pages,
but those I feel will add something, will.
Thanks for the interest, everyone!
See Ya....John 'Plasma Boy 'Wayland
Pestka, Dennis J wrote:
Just looked at the new "White Zombie History" link on John Waylands
Website.
Fantastic !
Thanks for all the time spent to put "that" together.
Really helps you appreciate all the time and engineering that went into
getting to where you are today.
Great Job !
Dennis
Elsberry, MO
http://www.plasmaboyracing.com/reviews.php
--- End Message ---
--- Begin Message ---
> When ya'll buy special stepped cylinders, might I also suggest "multi
> fire"
> spark plugs... guaranteed to increase your MPG and performance by 20%???
> <vbg>
Yeah, I was going to get some of those, but they don't make the correct
size for my electric truck yet.
--
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.
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--- Begin Message ---
Ok for the moment we'll ignore the fact that car size hub motors are
basically unavailable.
The main part of the car is "sprung" it rides on the suspension and
doesn't move up/down (much) when you hit a bump.
Unsprung mass is the weight in the wheels, tires. axle, etc. that is not
carried by the suspension.
I.e. it's the mass that HAS to move up/down when you hit a bump regardless
of how good your shocks/springs are.
This is bad for efficiency because it takes energy to move mass. Some (but
not all) of this energy is stored in the springs. The rest is wasted as
heat in the shocks (that's their job). The more comfortable the ride, the
more energy that gets wasted.
Its bad for handling because the more mass you have that is unprung, the
harder it is to keep it on the ground when you are on a bumpy road. If
the mass is high enough, and the suspension is soft enough, and the bump
is harsh enough, then the wheel can actually leave the road temporarily.
If the wheel isn't on the road, then it can' provide any cornering or
stopping ability.t
Even if the wheel doesn't actually leave the road, if the downward
pressure drops (sort of half leaving the road) then the cornering and
braking are decreased.
You can stiffen up the springs to help hold the wheels down, but then more
of the bumps get transfered to the vehicle, which makes it more
uncomfortable. I think this also reduces efficiency since even more mass
is being made to move.
Probably the best work around is to mount the motor to the chasis at an
inboard location and drive the wheel through a drive shaft. This takes up
a bit more room, but makes the motor 'sprung' weight. Of course you still
have the problem with finding a motor that can direct drive the wheel.
These are extremely expensive which makes them basically unavailable.
So you need to add a gearbox or something to reduce the motor's RPM to
something appropriate for the wheels. Probably in the neighborhood of a
5:1 reduction.
If you are going to go with individual motors for each wheel, then you'll
need individual gearboxes. This will take up more room and wieght. So
you are better off using a single larger motor (probably more efficienct
than multiple small motors) and a single larger gearbox (lighter than
multiple gearboxes) and split the drive force to the wheels using a
differential.
Hmm, this seems to be the way that most folks build EVs.
>
> in discussions about direct drive electric motors it's often mentioned
> that one of the design problems (or drawbacks) to this approach
> is that the motor (presents) an unsprung mass (or weight) (to the wheel?)
>
> can someone explain what this refers to / what it means and potential
> work-arounds / solutions?
>
> I'm interested in pursuing front wheel direct drive
>
>
> I asked a friend of mine who is a mechanical engineer
> (and BTW a self-styled genius) and he wasn't familiar with the term.
>
> thanks,
>
> Jonathan
>
>
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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.
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--- Begin Message ---
That's what my EV uses, disc brakes in the front and drums in the back. In
mixing these two brake systems, normally all cars have a proportional valve
that equalize the pressure to the front brakes and the rear brakes.
In this type of braking system, there are two lines coming from the master
brake cylinder that goes to the proportional valve. One line is the
pressure line and the other line is a relief line which is smaller, that
returns the brake fluid.
There are two separate front brake lines that come from the proportional
valve and one larger line that goes to the rear brake drums.
Sometimes the proportional valve is use for front and rear brakes.
The brake bleeding order is to bleed the 1st one closes to the proportional
valve and proceed to the brake that is further from the proportional valve.
Roland
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, February 14, 2007 9:24 AM
Subject: Re: Brake Pressure Multiplier?
> > The GM EV1 had front disk brakes. I wonder how they were designed? It's
> > probably one of the rare vehicles where someone actually thought about
> > the
> > problem, and may have tried to eliminate it.
>
> I seem to recall that they redisigned the seals slightly to give a bit
> more pull-back. I think they might have used the extra brake travel for
> regen.
> Might be worth looking into what some of the more efficient hybrids are
> doing.
>
> > How would people feel if I used drum brakes on the Sunrise kit car?
>
> How about a compromise, drums in the back and discs in front?
>
> 1/2 the drag and all the stopping power.
>
> --
> 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.
>
>
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