EV Digest 4111
Topics covered in this issue include:
1) RE: Side pull (Re: 42-volt...)
by "Roger Stockton" <[EMAIL PROTECTED]>
2) Re: NEDRA Wattage Classes
by Otmar <[EMAIL PROTECTED]>
3) posted ProEV's first Lithium Polymer test drive
by "ProEV" <[EMAIL PROTECTED]>
4) RE: 42-volt starting batteries
by "Roger Stockton" <[EMAIL PROTECTED]>
5) Re: New venting batt
by Lee Hart <[EMAIL PROTECTED]>
6) Re: Battery resting voltage...
by Lee Hart <[EMAIL PROTECTED]>
7) Re: Stuffing the brains into my variac
by Lee Hart <[EMAIL PROTECTED]>
8) RE: Torque Steer
by David Dymaxion <[EMAIL PROTECTED]>
9) Re: NEDRA Wattage Classes
by "Roderick Wilde" <[EMAIL PROTECTED]>
10) Re: 144vdc charger options needed, was Re: help
by Lee Hart <[EMAIL PROTECTED]>
11) Re: NEDRA Wattage Classes
by Otmar <[EMAIL PROTECTED]>
12) Re: Is Dennis getting bored?
by [EMAIL PROTECTED]
13) Re: 144vdc charger options needed, was Re: help
by russco <[EMAIL PROTECTED]>
14) RE: Torque Steer
by "Roger Stockton" <[EMAIL PROTECTED]>
15) Re: Is Dennis getting bored?
by "Rich Rudman" <[EMAIL PROTECTED]>
16) Re: Vespa conversion candidate on eBay
by [EMAIL PROTECTED]
17) Thanks
by "goodsharonwbird" <[EMAIL PROTECTED]>
18) Cluttered and Complicated...White Zombie Mods
by John Wayland <[EMAIL PROTECTED]>
19) Re: Side pull (Re: 42-volt...)
by Victor Tikhonov <[EMAIL PROTECTED]>
20) Re: Torque Steer
by Victor Tikhonov <[EMAIL PROTECTED]>
21) Re: Side pull (Re: 42-volt...)
by "M.G." <[EMAIL PROTECTED]>
22) Re: Torque Steer
by Victor Tikhonov <[EMAIL PROTECTED]>
23) Re: Side pull (Re: 42-volt...)
by Victor Tikhonov <[EMAIL PROTECTED]>
24) Re: What are the upper voltage limits of DC motors?
by "M.G." <[EMAIL PROTECTED]>
25) Re: 42-volt starting batteries
by Victor Tikhonov <[EMAIL PROTECTED]>
--- Begin Message ---
Victor Tikhonov [mailto:[EMAIL PROTECTED] wrote:
> I do not understand what length of the half shaft has to do
> with transmitting torque drom its one end to another.
Two things: the longer shaft may 'wrap up' (twist) more when torque is
applied; also the CV joints will operate at different angles on the
short shaft than on the long one (not sure how much effect this has, but
it is there).
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
I too would love to hear from others that I highly respect such as
Lee and Oat.
As I understand the question, it's how to best classify drag racing
vehicles.
That of course would depend on what the goal is.
Do you want them all to run close to the same speed? Spec. parts.
Do you want the most efficient one to win? Spec. power.
I think it's important to foster innovation, but also to provide some
areas where you can't just buy your way to a win. I don't know the
best way to do that, it's a difficult issue.
I think the voltage classes are pretty good because low voltage is
usually much cheaper. But of course lithium is going to allow people
to buy a win in any category. Yet, I don't want to penalize lithium
since I believe it will keep getting cheaper and better.
If you want low cost, innovative competitive racing, then I would
stick to the voltage classes but further limit some class to lead
acid only, or maybe even spec the battery model and quantity. (say,
12 Orbitals). Basically a power limit. That would keep cost down and
let people work on the details other than batteries which are
relatively cheap.
Really though, I don't know what is best. I am thankful that NEDRA
has already done such a great job thinking this out!
As for the solar race, I would think it's best benefit would be for
innovative experiments including thermal engines and the like.
Unfortunately the rule #1 does not allow that, so I don't see what
will be done to make it interesting.
just my 2 W*hr (thanks David D for the correction :-)
--
-Otmar-
http://www.CafeElectric.com
Mailto:[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
Hi Everybody,
We are filling in some gaps on our website.
Under Electic Imp Project, Testing Log, Vehicle testing log we added the
last of the information about our testing with the old hawker cyclon pack.
May 14, 2003 .... on is new.
June 24, 2004 covers our first test drive with the Kokam Lithium Polymer
cells.
Under Testing Log, Battery test log, we have posted a look at voltage under
load vs State of Charge on the Kokam's. Sorry about the Excel file, but it
was easiest to do the graphs in.
Cliff
www.ProEV.com
--- End Message ---
--- Begin Message ---
Victor Tikhonov [mailto:[EMAIL PROTECTED] wrote:
> OK, I can run it few times if you ask nicely :-)
> I'm afraid, though it may not pass formal safety inspection.
Please, please! ;^>
>From the pictures on your site, I suspect you would not have much
trouble passing tech. You will need to provide an emergency shutdown
switch (I believe a toggle switch on a little plate that you can secure
under the trunk/hatch lid is sufficient, but it must be in a red
triangle).
> Performance of ACRX is very good, but I don't care about *a number*.
The importance of a number is that I don't have any way of knowing what
'very good' performance means to you. (I used to be quite content
driving a 1970 VW van, so 'very good' performance might mean something
totally different to me than to Rich Rudman, for instance.)
If I were to approach you for an AC drive system, how do I know which
one to buy? I can ask you what you used in your car and how it
performs, but if the answer is 'very good' rather than something
quantifiable, I still don't know which one to buy (or worse, I buy the
wrong one). I know you offer simulations to assist in the process, but
unless you have numbers to verify that the performance of your car
matches your simulation of it, I can't rely on the simulation of my
vehicle.
If the numbers show that an 80-100kW AC system actually delivers
performance comparable to or better than a similarly priced DC system I
think you'd find more interest in the AC systems. Right now, I get the
impression that we really don't know, and that the assumption is that
the AC system will be wimpier...
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Richard wrote:
> I'm wrestling with a new battery in an old string right now too.
> Seems like I have the opposite problem. The new one takes
> significantly longer (extra hour) to reach acceptance voltage
> than the others. I'm trying to figure out if I simply got a
> stale battery, or if this is normal.
>
> Many sources state that new batteries have less capacity than
> "broken-in" ones.
>
> What I haven't been able to find is information on how new batteries
> react differently to charging vs broken in ones. What's the group
> consensus?
A new lead-acid battery will generally have slightly less than its rated
capacity. As you cycle it, its amphour capacity goes up for the first
few dozen cycles. After that there is a long plateau, and then in starts
to slowly decline as it goes into its "retirement years".
So, if you put a new battery in a slightly old pack, it will probably
have less capacity than the rest. It might be the one getting the
deepest discharge, and so can be damaged before the older but well
broken-in batteries.
Conversely, if you put a new battery in a very old pack, it probably has
*more* capacity even new. In this case, it will be batteries in the rest
of the pack that are the weak links.
There's another complication. The efficiency of a new battery is
generally the highest, and it slowly drops with time and age. When you
go for a drive, you take the same number of amphours out of each
battery. So when you recharge, the new battery will generally reach
"full" sooner. If you are charging harder and longer to keep an old
pack working, you can damage the new battery before it has time to get
broken in.
--
"The two most common elements in the universe
are hydrogen and stupidity." -- Harlan Ellison
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
[EMAIL PROTECTED] wrote:
> Do all multimeters have adjustable calibration? Or just the
> expensive ones?
Pretty much all of them do, though in some cases it might not be
obvious.
Old analog meters had hand-painted (or machine-painted) scales, custom
made for each one. Or, they hand-picked the resistors; you would see
wire-wound resistors so they could pick the length to get the desired
resistance, then wind it on the bobbin.
Digital meters usually have trimpots, one for each range. Sometimes they
use a file or laser to trim the resistance film on a metal film
resistor. A few use a microcomputer, and have a programmable memory chip
that they save the calibration data in at the factory.
> Also, I've seen meters that feature "self-calibration" or "auto
> calibration". What does this mean?
The classic Intersil ICM7106 digital multimeter chip and its derivitives
(used in 90% of all inexpensive digital meters) features auto-zero. It
periodically shorts its own input, and adjusts itself to display "0000".
With zero volts input, they typically display 0000 with an alternating
+/- sign.
But, it does *not* set its own full-scale value. In fact, these chips
have a built-in voltage reference that is not very good. The accuracy of
meters with these chips typically vary a lot with temperature.
--
"The two most common elements in the universe
are hydrogen and stupidity." -- Harlan Ellison
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
damon henry wrote:
> OK, I guess it will be as straight forward as I thougt it might.
> I am using a Basic Stamp 2 (BS2-IC) which does not have a built
> in ADC, so I guess I will need to pick a couple of those up.
Then I think I would get an inexpensive digital multimeter with an
isolated RS-232 output. This provides an accurate, inexpensive, isolated
way to measure charging voltage and/or current.
--
"The two most common elements in the universe
are hydrogen and stupidity." -- Harlan Ellison
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
I agree that most of the time a problem will show up for both cases,
motor torque and braking, but it is possible to have a case where
braking is different.
First the more mundane case: Before you stop, natural coasting
rearward force takes up that slack, so then braking doesn't make
things any worse.
Now for a less likely, but possible case:
Torque from the motor tends to pull the wheels fore or aft, and the
torque gets reacted through the transmission. The only torque about
the axle, on the suspension parts, is the very slight drag from the
bearings.
The brakes react their torque through suspension components, not the
transmission. This tries to rotate the suspension components about
the brake disk axis. Unlike the engine torque case, now the top of
the strut gets a significant forward force, and the lower control arm
ball joint gets a signficant rearward force. Movements of these
components could even cancel out!
You can get cases where things clunk loosely under engine torques,
but when tightened up by the braking torque don't clunk around.
--- Roger Stockton <[EMAIL PROTECTED]> wrote:
> Victor wasn't clear if the pull is transient or not, but I suspect
> loose
> parts are not the problem based on his description.
>
> He stated that the pull is experienced when he acclerates or
> decelerates
> using regen, but not when he decelerates using his brakes.
>
> Loose parts in the suspension would be forced one way under
> acceleration
> and the other way under deceleration; the behaviour would not
> depend on
> whether deceleration is applied at the wheel (brakes) or via the
> axles
> (motor).
=====
__________________________________
Do you Yahoo!?
Yahoo! Mail - You care about security. So do we.
http://promotions.yahoo.com/new_mail
--- End Message ---
--- Begin Message ---
Although I agree with much of what Rich said, I don't agree with his
statement on the one hand that there are too many classes and then on the
other that he is being pitted unfairly against race only cars as he said:
"I am tired of getting my butt kicked with rear drive cars, and Multi motors
and multi controllers. Not to say I couldn't vanquish them, it's just a LOT
of work. Classes are supposed to keep like same EVs in close competition.
Our voltage only classes, can put me against 2000 amps and twin motors and a
set of Wheelie bars. Something Goldie will never have."
First of all Rich you know darn well that we don't run voltage only. The
voltage divisions are a subcategory of different types of body types from
street conversions to full blown dragsters so that people like you with a
street car won't have to run against an all out race car with wheelie bars.
In fact the more classes we have the fairer it gets. We were very concerned
with fairness when we first wrote the classes. This was a great deal of work
and out of pocket expense to the people who flew to Arizona to form NEDRA.
The beginning was two days of all day long intense meetings. There had been
weeks of emailing ideas back and forth. We all took this very seriously.
As to your statement that: "Not to say I couldn't vanquish them, it's just
a LOT of work." You hit the nail on the head. It is a LOT of hard work and a
LOT of dedication to build a quick car. It certainly doesn't happen
overnight.
Roderick Wilde
NEDRA President
----- Original Message -----
From: "Rich Rudman" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, February 18, 2005 1:04 PM
Subject: Re: NEDRA Wattage Classes
----- Original Message -----
From: "Roy LeMeur" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, February 18, 2005 12:17 PM
Subject: Re: NEDRA Wattage Classes
Roderick Wilde wrote:
I figured this would get a reaction outta you Rod :^D
Gimme a break, I am playing devil's advocate here. You may be right
concerning NEDRA classifications, though there are some folks who would
disagree.
I am very aware of the difference between power density and energy
density,
some of us have lots of density.
I would love to see some other EVDL folks chime in on this.
Otmar? Rich Rudman? Joe Smalley? Lee Hart?
Who is real? We shall see.
See ya at the races!
Roy Rod, Nedra folks...listers..
A lot of time was spent figuring out the classes. Way back in what 97,
98??
That was then this is now I would think we all have a slightly better idea
of how to do it now.
There are way too many classes.
I am tired of getting my butt kicked with rear drive cars, and Multi
motors
and multi controllers. Not to say I couldn't vanquish them, it's just a
LOT
of work.
Classes are supposed to keep like same EVs in close competition. Our
voltage
only classes, can put me against 2000 amps and twin motors and a set of
Wheelie bars. Something Goldie will never have.
So I have my issues, but I am not crying foul, I am dealing with a NON
record carring EV.
As many of the good and Bad ideas, The Clouds seam to find ways of making
things harder, for thier compeditors, and easier for themselves. Hey
that's
one way to Race.
It's really clear that a Watt class is NOT going to work at all, there
will
be just too many ways to fool the judges and inspectors.
Some guide lines could be used:
Controller amps...number of motors, Rear Vs front drive....Street
legal...Battery chemistry. Total EV weight. Lots of good ideas. The
founders
chose battery voltage, It was not a bad idea at the time.
It still isn't at this time, though I do see some need to refine the ideas
for our future.
I have been also told that a 20 second time limit may be applied to REAL
NHRA tracks. If you can't do 20 seconds, you get shown to the trailer.
Power and energy density have little to do with the rules, and everything
to
do with the actual race.
The tech inspector and the NEDRA excutive board need to talk this over,
and
come out with a sane angle of approach. Having 4 times as many classes as
actual entrants, Says change is needed.
Goldie should be fighting with the Wabbit, and Robert Salem's VW truck.
All
single motor, tranny shifted ,front drivers. Voltage is kinda Moot when we
all have traction issues at 1/2 our peak power capabilities. And I could
tripple my power...with a Zilla 2K and 240 volts.
--
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--- End Message ---
--- Begin Message ---
jerry dycus wrote:
> What are the options to charge a 144vdc pack
> of t-105's that's automatic as the customer isn't that
> technical.
$300 doesn't buy much of a charger. It will of necessity depend on the
user for control. If the user is completely non-technical and can't be
trusted to do anything more than plug it in and turn it on, then you
*really* have a problem.
Let's see... here are some options for a cheap 144vdc charger. The one
with the worst charging algorithm is first, best is last.
1. Buy twelve 12v battery chargers for $25 each.
- straightforward, easy to find, many choices
- isolated outputs
- good battery balancing
- lots of wiring and mounting problems
- reliability problems (12 chargers will be 12 times less
reliable than one 144v charger)
- a $25 12v charger is either very low power (very slow)
or very poor quality
2. Build a "bad boy" charger with a buck-boost transformer.
- basically a bridge rectifier and transformer in a box
- dangerous; not isolated; must have GFCI
- charging voltage and current is unregulated; must be
manually watched and controlled
- has problems with dirty or wet batteries
3. Build a "third world" charger.
- basically, a suitable transformer and rectifier
- use a variac or switch transformer taps to control it
- can be set up to "approximately" charge the batteries right
- isolated
- needs a lot of experimenting
4. Modify a golf cart charger.
- most golf cart charger are 36v; rewire for 2x the voltage
(72v), and wire the 144v pack as two 72v packs for
charging.
- better charging algoritm
- isolated
- rather long charging times
5. Find a used 144v charger.
- depending on the charger, this could provide the best
overall results.
--
"The two most common elements in the universe
are hydrogen and stupidity." -- Harlan Ellison
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
At 1:53 PM -0800 2-18-05, Roderick Wilde wrote:
You hit the nail on the head. It is a LOT of hard work and a LOT of
dedication to build a quick car. It certainly doesn't happen
overnight.
Roderick Wilde
Hey Rod,
Why don't you tell that to that wild man that built a race car
overnight at Phoenix.
When was that? 1991 that you did that?
:-)
--
-Otmar-
http://www.CafeElectric.com
Mailto:[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
In a message dated 2/18/05 11:30:04 AM Pacific Standard Time,
[EMAIL PROTECTED] writes:
<< I venture ... enough to where Dennis can clobber Bill's Lithium with
> Hawkers. And have a EV that weighs about 2x Bill bike.
> I told Bill years ago... there's Magic to be made inside the motor case.
> >>
There is no way my Current Eliminator could get a better et with hawkers then
a Properly prepared drag bike with hi power denisty any kind of battery.We
are to heavy and lack the horse power to compete in that game.CE at best now
9something Dennis Berube
--- End Message ---
--- Begin Message ---
The four most popular chargers for a 144 volt system, are, in order of
price:
RUSSCO SC18-120 (USA non isolated with GFCI) with boost $812.
K & W BC-20 (USA non isolated with GFCI) with boost $820.
ZIVAN NG3 (Italy isolated) $879.
PFC PFC-20 (USA non isolated without GFCI) $1500
Prices are from EV Parts and KTA Services.
Russ Kaufmann
RUSSCO Engineering
The other PFC Charger
----- Original Message -----
From: "jerry dycus" <[EMAIL PROTECTED]>
What are the options to charge a 144vdc pack
of t-105's that's automatic as the customer isn't that
technical.
Do Lesters go this high?
What other chargers will work. Price?
Anyone have a used one for sale?
Sharon really needs help here and we should
give it as they are one of the few people building
EV's now!!!
Thanks,
jerry dycus
--- End Message ---
--- Begin Message ---
David Dymaxion [mailto:[EMAIL PROTECTED] wrote:
> First the more mundane case: Before you stop, natural
> coasting rearward force takes up that slack, so then braking
> doesn't make things any worse.
Hmmm... I don't see this as a possible explanation, at least in this
particular case. If there were slop that gets taken up by natural
braking forces such as coasting such that there is no pull while
coasting or braking, then it doesn't seem possible that that slop could
result in a pull while regenning.
> Now for a less likely, but possible case:
>
> Torque from the motor tends to pull the wheels fore or aft,
> and the torque gets reacted through the transmission. The
> only torque about the axle, on the suspension parts, is the
> very slight drag from the bearings.
This is an interesting possibility. I don't see how the reaction of the
braking torque through the suspension components would result in a pull
given that it would only act to very slightly reduce castor. If the
wheels were cranked hard over, it could affect camber also, but it seems
unlikely that there could be enough play to cause a this pulling problem
without Victor noticing more severe problems.
While I still think the obvious suspect is the unequal length axles
(perhaps compounded by some change Victor made during the conversion,
ride height, weight, tires, etc.), I wonder if your observation that
drive/regen torque is reacted through the tranny/motor mounts might not
be another clue. Perhaps the motor/tranny is shifting slightly under
acceleration/regen and causes a slight change to the steering geometry?
This change would not occur under braking and could also explain the
symptoms Victor is reporting.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
I know that Dennis!!
But you said "properley"... didn't you ???
My bet is with 4 times the power and 1/2 the weight, Bill still is going to
have issues putting that power to the ground.
Let alone actually turning all that battery power into mechanical power.
Dennis 9 something??? What yer getting slow in your old age!!!
Tired and abused Hawkers against something really secret and spiffy, but un
prepared motors and tires.....
Batteries can only take you so Far. Trade tick tock for Knock knock!
A fresh set of batteries is only a check away.
Now if Bill had been spending time working in his motors for the last 4
years... he would be ready to take you down a peg Dennis.
Getting tires to stick is just basic home work...If he only needs to do
that, Fear him Dennis.
Just a little time on the GoodSmear website... and Well maybe he could use
that growing tire with speed trick.....a couple inches Does matter... so
they say.
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, February 18, 2005 3:13 PM
Subject: Re: Is Dennis getting bored?
> In a message dated 2/18/05 11:30:04 AM Pacific Standard Time,
> [EMAIL PROTECTED] writes:
>
> << I venture ... enough to where Dennis can clobber Bill's Lithium with
> > Hawkers. And have a EV that weighs about 2x Bill bike.
> > I told Bill years ago... there's Magic to be made inside the motor
case.
> > >>
> There is no way my Current Eliminator could get a better et with hawkers
then
> a Properly prepared drag bike with hi power denisty any kind of battery.We
> are to heavy and lack the horse power to compete in that game.CE at best
now
> 9something Dennis Berube
>
--- End Message ---
--- Begin Message ---
<<< Question is where will everything go? If you could take out the Gastank and
put batteries maybe.?????? It does look like you could put an ETEK where the
fan is. Wonder if you could keep the transmission. LR.......>>>
Actually, you'd replace the entire drive unit, since the swing arm is also the
engine and tranny case. This was the situation with the eLamby; I altered a
REVI's swing arm to fit, but had to mount the Etek **underneath** it. For a
Vespa, I would mount batteries inside both side cowls and make sure their
attachment to the body was tough enough to handle the weight (and while at it,
probably make fiberglass copies of the original parts) - obviously I'd be
thinking of numerous li-ion cells (a'la Tzero) or li-poly (which could be
mildly bent to the curve of the cowl without damage). Put controller and
charger where the gas tank went and it would still look stock. You can do
without a tranny - with 48V/300A fed into an Etek, my eLamby is almost too
torquey at take-off and hits over 50mph, so I will be replacing the 23T
sprocket with a 28T one and expect a top end over 60mph.
--- End Message ---
--- Begin Message ---
Hi Guys, I want to tell you all "thanks", we found a good used
charger from the site, again you all came through, Thanks again..
and I do know that a good charger cost alot, we now have a guy
from here that will be mnakeing them for us. again Thanks .. Sharon
--- End Message ---
--- Begin Message ---
Hello to All,
>From Lawrence:
> You might take a look at Al Godfrey's latest porsche. While the front is
> full it is hardly cluttered. You can compare it to John's Zombie on page 4
> though that might be unfair.
> The Zombie is neat but designed for quick access as a drag car.
>
>
>From Damon:
> This picture also does not include the new SCR that John installed for his
> afterburner bypass mode. It is fairly large and looks like something
> straight out of Dr. Frankenstein's lab.
>
Interesting reading...I too, admire Al Godfrey's work. He's told me, that the
inspiration
for the way he puts his EVs together came from his first meeting with Blue
Meanie at one
of the early days VEVA electric car shows. Al does a great job with design,
layout, and
detail.
Uh hmmmm...as to White Zombie, yes, quick access is extremely important when
designing and
building a racing machine, but it's also important to do sano work, so that
those who come
to watch the car race, then gather around it in the pits, see quality
workmanship and can
get a good view of things. I've often thought of putting both motors in the
back of the
car, just ahead of the rear end and under a new, widened driveline tunnel. This
would
eliminate lots of rotational mass in a long driveline, and would really open up
the
under-hood area, but, it would also get rid of the most exciting aspect for
gasser dudes
first being exposed to electric power....seeing those two electric motors under
the hood!
Additionally, it would make it nearly impossible to check the brushes,
connectors, coms,
etc.....all VERY important track side! It's also helpful that once under way
down the
track, through the wide-open radiator grill, the motors get cooled off with 100
mph wind.
Several of my good friends have recently pointed out, how the Zombie is
starting to loose
it's clean look under the hood, and that I need to tidy things up a bit...I
agree. In
fact, I'm currently doing just that, as together with my friend and coworker
Tim Brehm,
we have been working long weekend days and nights redesigning areas of the car.
After the last 13.6 second run at Woodburn, that old bug-a-boo of mine, that
relentless
power train vibration the car's always had, got much worse. We've torn the car
down and
have checked everything again. Problems found this past Saturday:
(1) The rear motor's output shaft flanged hub had come loose, even though all
three of its
set screws are doped with red Loctite, and it had slid back a half inch on the
shaft towards
the rear of the car.
(2) Repositioned and re-secured, the hub still has a wobble that 'may' be the
source of
all the past and present vibration problems. This weekend, a dial indicator
will be used to
further check this out.
(3) The first half of the two piece driveline, due to the slid-back motor hub,
had shifted
back against the carrier bearing to where the grease cup was scraping against
the
bearing's outer race.
(4) One of the emergency disconnect's BIG power cables had moved a bit and was
being ground
on by the front driveline stub...not good!
(5) The front motor's splined output shaft hub that is part of the three piece
motor-to-motor coupler, had come loose and allowed lots of slack between the
motor shafts.
(6) Both rear brake drums were dragging badly, to where it took two people to
push the
car on level ground. Once the wheels are unbolted, the drums fit freely and do
not drag
at all....we're still investigating this.
Finding all the above, and considering a battery pack that was tired and needed
to be cycled
several times to bring them back up to high power levels, it's amazing that the
car was
able to
run a 13.6 at Woodburn!
Good things to report:
(1) The car is now fully loaded up with the 2005 race season's 288V pack of
Orbitals. Tim and
I ran the Orbitals through the table saw and made up all new 4/0 wiring for the
extra 4
back batteries. Although there's 160 extra lbs. of weight in the car, it gained
another 80
hp of battery
power bringing the total pack power up to 494 hp of electrical energy (each
Orbital pulled
to 7 volts at ~ 2200 amps)...hopefully, about 350 hp can be realized at the
motors!
(2) The motors will be removed. The motor support mount will be shortened about
4 inches.
The motor-to-motor coupler may be swapped out for a different type that will be
strong,
but shorter in length so the motors can sit closer to each other to fit in the
shortened
motor support mount.
(3) To make it so the motors can sit lower in the engine bay and be positioned
horizontally instead of at their present ~ 15 degree rake that is causing
incorrect
driveline angles, the car's cross member is being drastically modified with a
dropped center
section to allow the motor support mount to sit 3 inches lower. The steering
idler arm and
tie rod are being redesigned to be dropped accordingly as well.
(4) A new, custom machined rear motor output shaft hub with an interference fit
is planned
as part of the new design.
(5) Now that the Dutchman rear end setup has the Ford 9 inch input flange dead
centered in
the car's driveline tunnel (it used to be offset to the passenger side by 4
inches), the
two piece driveline and center carrier bearing are being dumped in favor of an
all new,
large diameter single piece aluminum driveline.
(7) The Afterburner bypass will be perfected, with a new SCR and improved
turn-off
features.
(8) If the pack seems to have any problems (batteries are now 1.5 years old),
Exide will be contacted for a new set. I'm also working with others towards
trying a 336V
pack of 26 ahr Hawkers that will shave 400+ lbs. out of the car, but possibly
bring back battery
destruction problems :-)
Along with all this, the motors will be dressed up with new eye candy type
paint and
polished aluminum end bells. The under-hood high power wring will be totally
redone. The
control wiring looms will be tidied up and better organized. Under-hood lights
will make
nighttime viewing much better for race fans. Lots of other improvements are in
store, too,
including a freshened-up interior. I had an offer last Fall, from a small local
body and paint
shop, to repair some minor dings and repaint the car, so that might happen, too.
I'm determined to go deeper into the 12's, and am shooting for a 110 mph trap
speed.
The above mods should go a long way to helping me achieve this, but if there's
one thing
I've learned as I continue to gain more experience with EV drag racing, it's to
be more realistic
about achieving my goals. I know that a 12.2 @ 110 mph isn't going to happen
instantly .
More than likely, it will take many trips to the track just to get back into
the 12's, but,
you'll certainly hear me hootn' and hollern' when the car does anything better
than a
12.99 ... it 'will' happen. Maybe by the time Wooodburn comes around in late
July, mid
12's @ 104-105 mph will be on hand.
This should be a fun year of EV drag racing. I'm planning the Wayland
Invitational, a
NEDRA sanctioned EVent to coincide with the Woodburn races. Imagine the
reaction from
hundreds of race fans, as on a Friday nightvtricked out high power EVs descend
on PIR to
mix it up with the rice burners and muscle cars. Could you imagine what these
guys and
gals will do, if Maniac Mazda rolled onto the track? Imagine, Rudman with
showing up with
a Z2K, Orbital powered, 200+V Goldie. Geez, it makes me salivate, just thinking
of seeing
a Camaro get dusted by a little 'ol Fiesta with batteries! Bob Salem, bring
that VW pickup
back with
sticky meats and axles work...show those import freaks what an electric pickup
can do. Mr.
Hall, got that twin motor sedan ready at 240V...low 12s, high 11s?? Rich Brown,
any chance
of getting Dual'n 7 up here? Hmm, maybe Father Time will have his BIG motored,
narrowed VW
bug
finished by then!!vAll video cameras are welcome, as the footage will be
priceless!
See Ya.....John Wayland
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Frank Schmitt wrote:
This is what's happening: the long half shaft momentarily winds up,
while the short one doesn't (or to a lesser extent, anyway). This is
enough to make you feel a momentary tug on the steering (I'm assuming
it's momentary -- if not, then something else must be going on).
It pulls *continuously* while I accelerate - if it takes 5 sec
to go from still to 40mph, all 5 seconds it pulls. When I coast,
it rolls straight. When I brake using regen up to the stop
it pulls other way also continuously until stop.
THe road is flat, no perceivable ups and downs of the wheels.
I think something else is going on...
Victor
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David Dymaxion wrote:
I 2nd looking for loose parts in the front and rear suspensions.
The "torque steer" due to unequal length axle shafts is transient.
You apply torque, and at the first instant the shorter stiffer shaft
transmits more torque than the longer "twistier" shaft, turning the
car a little bit for a moment. Quickly everything hits steady state,
and both wheels are getting the same torque. The driver
subconsciously learns to correct for this and doesn't even notice it
after a while. Most modern cars are well designed and have very
little of this effect.
Twist of the shaft metal itself> It is probably fraction of mm
and lasts for first 50 usec or so.
It pulls seconds at the time - as lond as it takes to accelerate
or brake.
Victor
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Comments inserted..
Victor Tikhonov wrote:
I do not understand what length of the half shaft has to do with
transmitting torque drom its one end to another. Of course twisting
shaft is negligible phenomena here.
Can you elaborate then?
Torque steer has been a problem ever since front wheel drives with
independent front suspension came about.
About torsion flex: if one half shaft flexes more, so the CV joint
has to work harder, naturally it eats away some torque to overcome
extra friction there, and net to the wheel will be slightly less.
The engineers , if they have enough money work very hard to eliminate
this. I know SAAB has special valving in their steering rack to help
combat this issue.
That explains it except the fact that before ACRX didn't do it.
Well, may be riding height was different, which brings another
question:
Suspension height can disturb the steering geometry greatly . I
personally would not lower my car without doing a lot of homework.
Shouldn't this be the case (e.g. different torque at wheels) only
if the shafts are *normally* run at some angle?
If it is straight line out, it should be the same
torque as with rigid half-shafts (that is unless clever
engineers overcompensated one side internally knowing that
suspension has to travel and normal half-shafts
position is already at the angle, so the easier rolling
side (with less friction in CV joint) has to be slowed down
inside the gear box somehow, so the torque at the wheels is
equal? Now, if the car is lowered and shafts are straight,
equilibrium is off since "internal" compensation is still in
effect for normally angled shafts, but they are no longer angled.
Does anyone know for fact if something like this is the case?
From what I have seen they usually make the longer shaft larger in
diameter or they install a damper.
I can always raise front to the stock riding height (I have
coilovers) and check if anything changes, but if someone knows,
I may save trouble doing so.
I would advise doing so to help diagnose this type of problem. I would
suggest checking in your local for a good alignment shop which has
suspension modification experience and have them check your car
completely for any worn components, repairing whatever is necessary
without going overboard (i.e.; not everything can be bad to the point of
needing replaced) , and then performing a 4 wheel alignment setting
everything to factory specs. especially the front end. I seem to
remember you might have two different size tires on the front of your
car this would be the first place to start as the contact patch is
probably different side to side.
Good Luck !
Mike G.
Feel free to contact me off list and I will help as much as I can.
[EMAIL PROTECTED]
Thanks,
Victor
Roger Stockton wrote:
Typical FWD torque steer due to unequal length drive axles?
When accelerating or regenning, the torque is applied through the
unequal length drive axles; when braking the torque is applied right at
the wheel, so axle lengths have no effect.
Cheers,
Roger.
Frank Schmitt also wrote:
> My guess is the right half shaft, being the shorter one (this is a
> Honda after all) has less torsional flex than the left one.
>
> (Some people call this torque-steer, but that's actually a different
> phenomenon related to the location of the contact patch versus where
> the steering axis intersects the ground).
>
> -Frank
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Roger Stockton wrote:
David Dymaxion [mailto:[EMAIL PROTECTED] wrote:
I 2nd looking for loose parts in the front and rear suspensions.
Victor wasn't clear if the pull is transient or not, but I suspect loose
parts are not the problem based on his description.
Sorry if it wasn't clear - the pull is not transient but rather
continuous during entire acceleration or regen-slowing down time.
Coasting and braking with disk pads is OK (no pull).
Victor
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Of course, we're talking about strady state time,
not initial transient, and straight out shafts.
Victor
Roger Stockton wrote:
Victor Tikhonov [mailto:[EMAIL PROTECTED] wrote:
I do not understand what length of the half shaft has to do
with transmitting torque drom its one end to another.
Two things: the longer shaft may 'wrap up' (twist) more when torque is
applied; also the CV joints will operate at different angles on the
short shaft than on the long one (not sure how much effect this has, but
it is there).
Cheers,
Roger.
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Yes but which has a higher melting point?
Mike G.
Lee Hart wrote:
Peter VanDerWal wrote:
True; but higher efficiency is not always better. The above changes
lower efficiency, but increase the power-to-weight ratio. If they also
reduced cost, you would have *lots* of people that saw the motor as
"better".
Ok, ok, I see your point. However, since I'm primarily interested in
efficiency, "I" wouldn't call it an improvement ;-)
Ok; if efficiency is your god, then wind your motor with silver wire!
Silver also happens to be mechanically stronger than copper, which also
helps.
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Roger Stockton wrote:
Victor Tikhonov [mailto:[EMAIL PROTECTED] wrote:
OK, I can run it few times if you ask nicely :-)
I'm afraid, though it may not pass formal safety inspection.
Please, please! ;^>
OK Roger, I'll make a note. :-)
From the pictures on your site, I suspect you would not have much
trouble passing tech. You will need to provide an emergency shutdown
switch (I believe a toggle switch on a little plate that you can secure
under the trunk/hatch lid is sufficient, but it must be in a red
triangle).
Performance of ACRX is very good, but I don't care about *a number*.
The importance of a number is that I don't have any way of knowing what
'very good' performance means to you.
If I don't care abiut number, why should I care to race just
to supply this number to others? Sorry if this sounds rude, it's
not to say I don't care about others in general. It's just they make
me do extra work for what they want.
(I used to be quite content
driving a 1970 VW van, so 'very good' performance might mean something
totally different to me than to Rich Rudman, for instance.)
Again, why do you care what performance of *your* car as you define
it means to Rich if he isn't going to drive it? I won't cry if
Ormar won't tell me how fast his Porche is - what difference does
it make to me? Am I going to re-test it?
If I were to approach you for an AC drive system, how do I know which
one to buy?
This is entirely different issue - if you're talking to the vendor
you have right to demand performance numbers sold to you for money.
In this respect I must provide numbers. There are specs for them
though, and seeing actual vehicle's numbers may be more misleading
than beneficial since exposes other weak links (too hight R_int
of the batteries so the powerful drive system is underutilised
giving spectators wronf impression.
But I see your point.
If the numbers show that an 80-100kW AC system actually delivers
performance comparable to or better than a similarly priced DC system I
think you'd find more interest in the AC systems. Right now, I get the
impression that we really don't know, and that the assumption is that
the AC system will be wimpier...
Again, participating for marketing purposes is different animal.
And, it doesn't have to be *me*, it just have to be AC driven
car with somebody like Wayland behind the wheel.
It takes special kind of people to enjoy drags as much as John,
and I'm just not one of them. Not to say that I can't build
it for someone else to demo...
Cheers,
Roger.
Victor
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