EV Digest 6844
Topics covered in this issue include:
1) Another BMW conversion (1994 318ti)
by "Ian Jordan" <[EMAIL PROTECTED]>
2) Re: Another BMW conversion (1994 318ti)
by MIKE WILLMON <[EMAIL PROTECTED]>
3) Re: Careful!! Re: Prius project
by "Dave Davidson" <[EMAIL PROTECTED]>
4) Re: New to list and electric motor mounting question
by "Roland Wiench" <[EMAIL PROTECTED]>
5) Chevy volt batteries
by Eduardo Kaftanski <[EMAIL PROTECTED]>
6) Re: Another BMW conversion (1994 318ti)
by "Ian Jordan" <[EMAIL PROTECTED]>
7) The Husted Motor (was Re: Power of DC)
by Chip Gribben <[EMAIL PROTECTED]>
8) RE: Another BMW conversion (1994 318ti)
by "Roger Stockton" <[EMAIL PROTECTED]>
9) RE: 95 BMW 525i conversion
by "Roger Stockton" <[EMAIL PROTECTED]>
10) Anybody tried battery switching from parallel strings to series strings?
by "Marty Hewes" <[EMAIL PROTECTED]>
11) Re: Another BMW conversion (1994 318ti)
by MIKE WILLMON <[EMAIL PROTECTED]>
12) Last choice is TL EV was Careful!! Re: Prius project
by [EMAIL PROTECTED]
13) Re: Power of DC - AutoCross long winded response
by Dave Cover <[EMAIL PROTECTED]>
14) Re: 95 BMW 525i conversion
by Paul <[EMAIL PROTECTED]>
15) Re: Another BMW conversion (1994 318ti)
by "Ian Jordan" <[EMAIL PROTECTED]>
--- Begin Message ---
I'm thinking of converting a 1994 BMW 318ti hatchback to an EV, but
I'm a newbie to the EV stuff. Can someone glance at my plan and see if
it seems possible?
1994 BMW 318ti. Curb 2850, Gross 3900, RWD.
Range 30 miles (I could maybe live with 20)
0-60 in 6.0 sec or less
75+ MPH top speed
Direct drive, no transmission. 3.91 rear end gives me 75MPH @ 4000
RPM. I can get rear ends from 2.93-5.85 easily.
NetGain TransWarp 11" motor (or would two 9" be better for my plan?
Cost is about the same)
Zilla 2K controller
Flooded batteries, no idea how many, or what size.
Will I be able to get my performance requirements with this setup?
Can you run an advanced timing motor like the Warps in reverse in
order to get reverse out of a direct drive system? I know you can't
run them full time without messing with the timing, but is it OK for
very low duty cycle stuff like reverse?
--- End Message ---
--- Begin Message ---
I think that the RPM hit you'd take using the Netgain 11" might justify the two
9"s if you were going to going for 1/4 mile times. Although you would have to
implement a series parallel switching to make most efficient use of the battery
power.
Of course if you won't be racing, the 11" motor may just be simpler to deal
with.
You can get both the 9" and 11" in the TransWarp configuration now.
Mike,
Anchorage, Ak.
----- Original Message -----
From: Ian Jordan <[EMAIL PROTECTED]>
Date: Tuesday, June 5, 2007 1:14 pm
Subject: Another BMW conversion (1994 318ti)
To: ev@listproc.sjsu.edu
> I'm thinking of converting a 1994 BMW 318ti hatchback to an EV, but
> I'm a newbie to the EV stuff. Can someone glance at my plan and see if
> it seems possible?
>
> 1994 BMW 318ti. Curb 2850, Gross 3900, RWD.
>
> Range 30 miles (I could maybe live with 20)
> 0-60 in 6.0 sec or less
> 75+ MPH top speed
>
> Direct drive, no transmission. 3.91 rear end gives me 75MPH @ 4000
> RPM. I can get rear ends from 2.93-5.85 easily.
>
> NetGain TransWarp 11" motor (or would two 9" be better for my plan?
> Cost is about the same)
>
> Zilla 2K controller
>
> Flooded batteries, no idea how many, or what size.
>
> Will I be able to get my performance requirements with this setup?
>
> Can you run an advanced timing motor like the Warps in reverse in
> order to get reverse out of a direct drive system? I know you can't
> run them full time without messing with the timing, but is it OK for
> very low duty cycle stuff like reverse?
>
>
--- End Message ---
--- Begin Message ---
Funny how the laws vary between states. I had a car totalled in Texas when
I was sideswiped. Just cosmetic damage, nothing structural at all. When I
bought the car back for salvage, the money was just deducted from the check
they issued me and the title was never exchanged. I never fixed the car and
drove it for several more years.
Dave
From: "chad plantenberg" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: Careful!! Re: Prius project
Date: Tue, 5 Jun 2007 09:22:28 -0700
a couple of notes:
i suspect that there is more than just one dented fender to the prius.
since insurance 'totals' a vehicle when estimated repair cost (of
course the inflated estimates) is greater than estimated value of the
car - i also had a car totaled for the reason (again, a deer) and
'salvaged' it so i could keep it (i think mine cost me $50 to buy
back. of course i got the $2000 insurance check and i fixed it for
less the $500, so i decided to get a nice paint job with the rest of
the money). that being said, i imagine a 04 prius is not going for
somewhere down near 2-$4000. so i imagine that there was quite a bit
more damage. (maybe he can share with us)
second note - i know here in cali you also only get to 'salvage' one
'vehicle' 3 times. after the third time, if it is considered a total
loss again by insurance, it is a mandatory off the road. thought i
would just throw that out for the common good.
On 6/5/07, Marty Hewes <[EMAIL PROTECTED]> wrote:
Yeah, I've got one car that's been totalled twice (a deer hit once, front
end sheet metal once), I repaired it both times, and still got years more
use out of it. It doesn't take much for the insurance company to call
something totalled, and I bought it back cheap both times. What a body
shop
bills an insurance company to repair a crunched car is a heck of a lot
higher than what it costs me to pick up used parts and do it myself.
Often
the insurance company will be very cooperative if what they are looking
for
out of the deal is a signature on a release form releasing them from
future
medical bills blamed on the crash. Their concern is more the liability of
a
trumped up injury case than the value of the junker.
When you hear that a friend totalled their car, ask questions quick! A
friend let a nearly new Corvette go cheap once, I'm still kicking myself.
Marty
----- Original Message -----
From: "Jeff Shanab" <[EMAIL PROTECTED]>
To: "Electric Vehicle Discussion List" <ev@listproc.sjsu.edu>
Sent: Tuesday, June 05, 2007 7:58 AM
Subject: Careful!! Re: Prius project
>I didn't catch where he is, but in California it usually means the
> vehicle was "totaled" by the insurance company. My 95 grand am was
> totaled by the insurance company, they gave me the check and then I
> bought it back for $161.00, The salvage value. The title goes to the
> insurance company then back to me as salvage without leaving my front
> yard. They like to do this, repair costs are comically inflated here.
> (dent to left front fender where off duty cop ran into it while it was
> parked. 3 estimates from "approved" body shops were within 10$ of each
> other at $3900 )
>
> I mention this because someone's EV may end up in a similar situation
> since most of us convert/recycle older vehicles.
> The first time I went through this I didn't know that I could buy it
> back for salvage value and lost a really good car, I wanted it fixed
but
> the insurance company insisted on totaling.(water damage to motor) I
> later found that the shop it got towed to bought it back for salvage
> value, fixed it, and resold it.
>
>
_________________________________________________________________
Get a preview of Live Earth, the hottest event this summer - only on MSN
http://liveearth.msn.com?source=msntaglineliveearthhm
--- End Message ---
--- Begin Message ---
Hello Brain,
I find its best to install the motor and transmission together as a unit. I
use a wood stand to hold the motor and transmission while I work on it.
Things to check out when mating a transmission to a motor adapter and
coupler.
The input shaft of the transmission should not butt tight into the pilot
bearing. You may to adjust the motor coupler if the pilot bearing is
install in the motor coupler.
Also you may have to shim the flywheel or shave off the back of the flywheel
so you have at least 1/8 inch of throw out bearing clearance.
You may have to use a short or long throw out bearing to get the clearance
to the pressure plate.
While this units is on your test stand and assembly, test out the rotation
with the transmission for these clearances. You may have to pull the
transmission several times to make these adjustments.
Other test you can do is, to rotate the motor with 12 volts, to see how much
ampere is draw. Then add the transmission again and load test it again.
There should be little change.
On the first initial installation of the motor, I first install motor and
transmission assemble from the top because the engine bay was gutted out at
that time.
Later if you have to remove the motor for maintenance, you will find that
your motor bay is jam pack with a controller, accessory drive units and etc.
It is best to engineer the motor and transmission mounts so you can remove
out the bottom.
What I did, was to shorten up the rear transmission cross member which
normally sat on top of the frame rails. Bolted on large steel plates to the
frame rails and then can lift up the motor and transmission with the
transmission cross member attach as one unit and bolt cross member right to
these plates from the bottom with 7/16 inch grade 8 bolts with no hassle.
I modified a floor jack that has a 3 inch U channel bolted into the jack
pad. A 2 inch square tubing that is about 40 inches long sets in this U
channel and can be pin at different holes.
At the motor end of the 2 inch channel, a motor mount is made from cutting a
large tubing in half so it can cradle the motor. At the transmission end it
mounts to the transmission cross member by either bolts or pins.
It takes less than 60 minutes for me to swap out motors and transmissions,
that is when I get the vehicle jack up on large heavy duty jack stands.
Roland
----- Original Message -----
From: "Brian Pikkula" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, June 05, 2007 2:59 PM
Subject: New to list and electric motor mounting question
> Hi, I'm rather new to EVs. So I thought I'd join the list and pick your
> brains.
>
> I've got a Jetta in which the ICE should be out this weekend.
> Here's my austive ev site http://www.austinev.org/evalbum/960
>
> I was wondering if it is 100% necessary to remove the transmission to
> mount
> the motor? I should have ample room to get around under the hood when
> the
> ICE is out. See http://www.austinev.org/evalbum/popupimg.php?49 for
> what
> it will look like when the ICE is out; however, in this this pic the owner
> did remove the transmission.
>
> Thanks,
> Brian in TX
>
--- End Message ---
--- Begin Message ---
http://www.autobloggreen.com/2007/06/05/breaking-gm-awards-two-battery-development-contracts-for-chevy/
--
Eduardo K. |
http://www.carfun.cl | I'm white and nerdy
http://ev.nn.cl | Weird Al
|
--- End Message ---
--- Begin Message ---
I'm really fine with a car that gets to 70 quick and then just runs
out of RPM/voltage/whatever. Not interested in total quarter mile
times, I just want a lot of oomph down low at normal 0-50 MPH city
speeds.
Is the tradeoff between a 9" and 11" motor the RPM limit? Can you spin
a 9" faster than an 11"?
I am sort of considering going to a single Transwarp 9" right now
knowing I could bolt on a normal Warp 9 at any time, once I have the
basics down.
--Ian
On 6/5/07, MIKE WILLMON <[EMAIL PROTECTED]> wrote:
I think that the RPM hit you'd take using the Netgain 11" might justify the two
9"s if you were going to going for 1/4 mile times. Although you would have to
implement a series parallel switching to make most efficient use of the battery power.
Of course if you won't be racing, the 11" motor may just be simpler to deal
with.
You can get both the 9" and 11" in the TransWarp configuration now.
Mike,
Anchorage, Ak.
----- Original Message -----
From: Ian Jordan <[EMAIL PROTECTED]>
Date: Tuesday, June 5, 2007 1:14 pm
Subject: Another BMW conversion (1994 318ti)
To: ev@listproc.sjsu.edu
> I'm thinking of converting a 1994 BMW 318ti hatchback to an EV, but
> I'm a newbie to the EV stuff. Can someone glance at my plan and see if
> it seems possible?
>
> 1994 BMW 318ti. Curb 2850, Gross 3900, RWD.
>
> Range 30 miles (I could maybe live with 20)
> 0-60 in 6.0 sec or less
> 75+ MPH top speed
>
> Direct drive, no transmission. 3.91 rear end gives me 75MPH @ 4000
> RPM. I can get rear ends from 2.93-5.85 easily.
>
> NetGain TransWarp 11" motor (or would two 9" be better for my plan?
> Cost is about the same)
>
> Zilla 2K controller
>
> Flooded batteries, no idea how many, or what size.
>
> Will I be able to get my performance requirements with this setup?
>
> Can you run an advanced timing motor like the Warps in reverse in
> order to get reverse out of a direct drive system? I know you can't
> run them full time without messing with the timing, but is it OK for
> very low duty cycle stuff like reverse?
>
>
--- End Message ---
--- Begin Message ---
Hey Mike,
It was Joe Lado. He won the motor. Joe is the guy in our EV club who
owns the bright yellow Dentiny 2000 electric Fiero.
Chip
On Jun 5, 2007, at 5:03 PM, Electric Vehicle Discussion List wrote:
From: MIKE WILLMON <[EMAIL PROTECTED]>
Date: June 5, 2007 4:14:02 PM EDT
To: ev@listproc.sjsu.edu
Subject: The Husted Motor (was Re: Power of DC)
Chip,
Who won the Husted motor?
I need to know what seller to look for on e-bay when it goes up for
bids ;-P
Mike Willmon
--- End Message ---
--- Begin Message ---
Ian Jordan wrote:
> I'm thinking of converting a 1994 BMW 318ti hatchback to an EV, but
> I'm a newbie to the EV stuff. Can someone glance at my plan and see if
> it seems possible?
>
> 1994 BMW 318ti. Curb 2850, Gross 3900, RWD.
>
> Range 30 miles (I could maybe live with 20)
> 0-60 in 6.0 sec or less
> 75+ MPH top speed
>
> Direct drive, no transmission. 3.91 rear end gives me 75MPH @ 4000
> RPM. I can get rear ends from 2.93-5.85 easily.
>
> NetGain TransWarp 11" motor (or would two 9" be better for my plan?
> Cost is about the same)
>
> Zilla 2K controller
> Flooded batteries, no idea how many, or what size.
Just as a WAG, figure you might need about 370Wh/mi, so 11.1kWh for 30mi
range. If you use floodies and don't take them below 70%DOD (for decent
life), a 120V or higher pack T105s should get you the range. This is
1300lbs of batteries. It is pretty much guaranteed that you can't meet
the 0-60 target with floodies.
The Z2K is overkill if you use floodies; you'll be paying for
performance that you can't take advantage of. A Z1K is probably a
better match to the flooded pack (a Z2K turned down to 1000-1500 motor
amps might live "forever", but Z1Ks aren't exactly known for dying
young...).
The Transwarp's output makes it very attractive for a direct drive
setup, but I expect a pair of 9's with a Z1K and series/parallel shift
would perform very well and might prove more reliable due to the greater
comm/brush area.
I'd think that 240v of AGMs such as Optimas (<1000lbs), a pair of 9's
and a Z2K would come closer to meeting all of your goals. 30mi should
be possible on occasion by pushing the pack to a deeper DOD, while 20mi
on a routine basis should be no problem. The 9's can be safely spun a
bit higher than the 11, which might let you gear to make the 0-60 easier
to meet.
Have a look at Matt Grahams 240SX; it's just about what you are hoping
for, I think:
<http://www.austinev.org/evalbum/836>
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
John Wayland wrote:
> I love it when Roger and I can have a little fun...
John, it is always a pleasure! There isn't any chance that you will be
in Vancouver (BC) this weekend (VEVA EV show) to continue it in person,
is there? You've got a place to stay if you need it.
> I actually thought about it, but dismissed the reality
> and practicality of it.
> In this heavy car, to get the same DC torque at the wheels
> with the proposed AC system, he's going to have to somehow,
> find a BMW rear gear set in the 7:00 ratio range.
Not (quite) so. I didn't have much luck digging up specs on the '95
model year, but the later years seem pretty consistent with the 2005
specs reading 175ft-lbs max, 3.15:1 final and
4.35/2.50/1.66/1.23/1.00/0.85 for 1st through 6th gear. The auto
version has a 3.73:1 final and the including the option of using a rear
end from another 5-series model there are 3 or 4 choices spanning the
range of 2.93:1 through 3.73:1.
A DC conversion typically ignores 1st gear, while the AC drive option
would use it and achieve a 1.74x additional torque multiplication over
the DC system in 2nd.
Extrapolating the ADC 9" torque curve out to 1000A, it looks to me like
your estimate of 300ft-lbs is a bit optimistic; 238ft-lbs looks more
probable (and may still be on the optimistic side). On 144V the 9" will
probably start going to sleep at much over 3000RPM (it looks like it
would be down to about 100ft-lb by 3500-3700RPM) - this gets the 525 to
about 30mph in 2nd. While one might not want to risk spinning the stock
flywheel & clutch assembly up to 10000RPM with the AC drive, it could
easily run to 6000RPM in 1st which gets the AC drive 525 going about the
same 30mph. While torque (and therefore acceleration) is falling off
most of the time the 9" is spinning up, the AC drive in 1st would be
delivering 20% more torque to the wheels (165ft-lbs x 1.74 = 287ft-lbs
vs the 9"'s 238ft-lbs) until it also hits constant power.
The 9" can't spin fast enough in 1st to hit 30mph, and so while one
could start in 1st with the DC drive and have even more torque than the
AC drive, it would mean having to shift to 2nd by 10-15mph to approach
the AC system's shiftless 0-30mph performance.
I just don't think it is quite as cut-and-dried as it might seem at
first glance.
Of course, I am assuming that nobody in their right mind would fork out
for an AC drive without feeding it from a proper battery pack, so yes,
it is a given that the AC drive would be fed from a 300v+ string, not
the same 144V string of floodies that the lower buck DC system could get
away with.
I looks very much to me as if the AC system and DC system would provide
very similar performance in terms of acceleration and top speed. The AC
system would cost more, so for the same dollars a higher performing DC
system could be had, however, Guy seems more concerned with range than
the best possible 0-60 time. I don't know that either system could meet
his range requirements, but the AC drive is generally acknowledged to be
a bit higher efficiency than the typical DC system, and regen could
offer 10% or better improvement to the range depending on the driving
conditions.
In terms of what's available now, the lower voltage DC system requires
that batteries capable of at least several hundred amps are used, which
pretty much limits it to large floodeds or a short list of the better
AGMs. A higher voltage AC system could use batteries with more modest
current capabilites, such as gels, or lighter options such as Valence
LiIon (a string of the 65Ah 18V modules or 12V 100Ah modules, for
instance), or Cobasys 85 or 100Ah 12V NiMH modules, etc. (Yes, I know
this is even more money...)
> Keep in mind, that while Guy is shopping around for these costly
> gears, he'll still have to now change his simple, easy, and low
> cost flooded cell pack to a more expensive AGM pack with 25-30
> BMS regs for each battery, too.....again, AC makes the cost of
> Guy's conversion go through the roof.
I don't know that a 144V flooded pack is even an option anyway: can it
physically fit? Remember, floodies have to be installed vertically, and
must be accessible from above for watering and cleaning, etc. Even
cramming the engine bay and trunk full may not be enough without tossing
the rear seat and stuffing more where it used to be.
If he goes higher voltage, he has options other than expensive AGMs
(though they may still be expensive options ;^). With a sufficiently
intelligent charger regs aren't a necessity, and if a chemistry other
than PbA is used the BMS/regs may be included in the battery or may not
be required.
Just as there are reasons other than economics for choosing one's donor
vehicle, there are factors other than cost that influence the drivetrain
choice. A 525i isn't the donor one chooses if cost is the most
important major consideration! ;^>
That said, I think the hand waving has shown that available AC or DC
could provide similar performance, but AC will cost more for the same
performance level. Since the range goal is quite aggressive, I would
suggest that it might be more prudent to use the cheapest drivetrain and
put the savings into the best possible battery pack unless the
additional features of the AC drive (regen, liquid cooling,
brushless/idiot-proof nature, etc.) justify the additional expense for
the guy who is actually footing the bill.
> Ever priced 1500 lbs. of AGMs 'and' their BMS?
About $4k ballpark for 20-21 group31's. Priced floodies lately? ;^>
> Again as I've already stated, I'd use AC in White Zombie in a
> heartbeat, if it were even remotely affordable at the 350kw+
> power levels I'm operating at...
Have you got that beast on a dyno yet? It would be really interesting
to know just how much of the battery kW makes it to the wheels. You
might be surprised at what a 10-20% more efficient drivetrain could do
to alter your perception of the battery HP required to match the preset
performance... (I don't know what sort of efficiency edge an AC system
might offer; that's what makes it interesting! ;^)
Remember, you are running 2 DC motors (let's not quibble over the
one-motor/2-motor 1shaft/2 shaft thing; you know what I mean and I
concede to however you want to spin it ;^) - the point is that you may
be getting away with a single controller, but you had to go to twice the
motor to reach your present performance level, so it might be reasonable
to consider a pair of AC drives in comparison... (yeah, this doesn't
help the "remotely affordable" bit, but you're the "sponsorship king",
so surely you have the best chance of anyone of being able to wrangle
some deal with Brusa or Siemens or ABB, etc. ;^)
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Maybe I'm misunderstanding controller operation. I'm assuming the current
limit on the motor side of the controller is limiting peak current during on
time, not average, since semiconductors are peak sensitive? The current
limit on the battery side (if it's programmable), is more concerned with
average, since that's what batteries care about?
I'm contemplating the fact that at low RPM with high battery voltage, it
seems like you'd be operating at very narrow pulse widths, with high
currents during the narrow pulses causing the controller to current limit,
limiting power, no? If the pulse width was at only 25%, and you want to be
able to use 500 amps of battery, then the motor would see 2000 amps during
the on time? If your controller limits to 1000, you're out of luck? If the
battery voltage was lower (cut the string in half and parallel the halves),
at the same power output, the pulse voltage would be lower but wider.
Therefore the current during the on time would be lower, 50% on time at 1000
amps in the case above? No controller current limit? Once the RPM rises
enough that the back EMF limits current, then you'd want to series the
battery strings? Seems like series/parallel switching battery strings may
act somewhat like dual motor switching without requiring two motors? Am I
misunderstanding the motor side current limiting functions of controllers?
Thanks in advance,
Marty
--- End Message ---
--- Begin Message ---
2000A from a Zilla to a TransWarp9 direct drive to a 3.91 rear end might get
you fairly decent acceleration.
With my truck and a 1000 amps to the single Warp9 with the Tranny in 4th (1:1)
to a 3.6something rear gear the accelerations was not dog slow, but I wouldn't
want to have to start off like that all the time. Starting off in 3rd was
quite acceptable when able to pull 1000 amps. However with 2000 amps on tap
the single 9" would probably give you a fairly reasonable acceleration *direct
drive* especially with your taller rear gear and presumably lighter weight than
mine.
As far as RPM goes between the 11" and 9" Netgains curves list the 11" at 4000
rpm and the 9" at 5600 rpm. Most likely the motors will safely exceed those
RPM's slightly, but I wouldn't count on it for warranty work.
2000 amps to a TransWarp11" will make you launch like a dragster but at 4000
rpm would top you out at around 67 mph.
2000 amps to the TransWarp9" will accelerate you fairly quickly but at 5600 rpm
you would be up to 94 mph.
Both assume 3.91 rear end and 22" tall tires.
Look at the motor curves on the Netgain site and you can see that at the same
currents, say 300 ish amps the 11" puts 80 lbs-ft and the 9" puts 60 lbs-ft.
approximately the same 25 horsepower though.
Or at the same rpm of 4000 ish RPM, the torque from the 9" is about 12 lbs-ft
and the 11" is down to 10 lbs-ft.
Now these are taken at 72V and presumably you will be hitting them hotter than
this. But the relative ratios will be about the same for making comparisons.
Mike,
Anchorage, Ak
----- Original Message -----
From: Ian Jordan <[EMAIL PROTECTED]>
Date: Tuesday, June 5, 2007 2:28 pm
Subject: Re: Another BMW conversion (1994 318ti)
To: ev@listproc.sjsu.edu
> I'm really fine with a car that gets to 70 quick and then just runs
> out of RPM/voltage/whatever. Not interested in total quarter mile
> times, I just want a lot of oomph down low at normal 0-50 MPH city
> speeds.
>
> Is the tradeoff between a 9" and 11" motor the RPM limit? Can you spin
> a 9" faster than an 11"?
>
> I am sort of considering going to a single Transwarp 9" right now
> knowing I could bolt on a normal Warp 9 at any time, once I have the
> basics down.
>
> --Ian
>
> On 6/5/07, MIKE WILLMON <[EMAIL PROTECTED]> wrote:
> > I think that the RPM hit you'd take using the Netgain 11" might
> justify the two 9"s if you were going to going for 1/4 mile times.
> Although you would have to implement a series parallel switching
> to make most efficient use of the battery power.
> >
> > Of course if you won't be racing, the 11" motor may just be
> simpler to deal with.
> >
> > You can get both the 9" and 11" in the TransWarp configuration now.
> >
> > Mike,
> > Anchorage, Ak.
> >
> > ----- Original Message -----
> > From: Ian Jordan <[EMAIL PROTECTED]>
> > Date: Tuesday, June 5, 2007 1:14 pm
> > Subject: Another BMW conversion (1994 318ti)
> > To: ev@listproc.sjsu.edu
> >
> > > I'm thinking of converting a 1994 BMW 318ti hatchback to an EV,
> but> > I'm a newbie to the EV stuff. Can someone glance at my plan
> and see if
> > > it seems possible?
> > >
> > > 1994 BMW 318ti. Curb 2850, Gross 3900, RWD.
> > >
> > > Range 30 miles (I could maybe live with 20)
> > > 0-60 in 6.0 sec or less
> > > 75+ MPH top speed
> > >
> > > Direct drive, no transmission. 3.91 rear end gives me 75MPH @ 4000
> > > RPM. I can get rear ends from 2.93-5.85 easily.
> > >
> > > NetGain TransWarp 11" motor (or would two 9" be better for my
> plan?> > Cost is about the same)
> > >
> > > Zilla 2K controller
> > >
> > > Flooded batteries, no idea how many, or what size.
> > >
> > > Will I be able to get my performance requirements with this setup?
> > >
> > > Can you run an advanced timing motor like the Warps in reverse in
> > > order to get reverse out of a direct drive system? I know you
> can't> > run them full time without messing with the timing, but is
> it OK for
> > > very low duty cycle stuff like reverse?
> > >
> > >
> >
> >
>
>
--- End Message ---
--- Begin Message ---
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* ---REMAINDER OF MESSAGE TRUNCATED--- *
* This post contains a forbidden message format *
* (such as an attached file, a v-card, HTML formatting) *
* Lists at sjsu.edu only accept PLAIN TEXT *
* If your postings display this message your mail program *
* is not set to send PLAIN TEXT ONLY and needs adjusting *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
--- End Message ---
--- Begin Message ---
Before lending my perspective to the days events, I just want to thank Chip and
Mike and Tracy and
everyone else who put this event together. There are a lot of details with a
weekend like this and
their planning made it a lot easier for me to attend. Thanks again for all you
guys have done.
This years PODC (my second time attending) was a sort of coming out party for
my car. It took a
lot scrambling to get the temporary plates so I could tow it down to MD. I was
hoping to have the
car registered, but CT DMV doesn't know their @$$ from a hole in the ground.
But that's another
story.
For me it was a long tow down and back. I have a towbar with permanent mounts
on the car. CT to MD
is over 8 hours, and it rained almost the whole time. Going down was
thunderstorm to thunderstorm.
Coming home, I had tropical storm Berry keeping me company. The last minute
plexiglass shield and
cloroplast belly pan kept my electronics dry. Whew!
As mentioned, my car is an 87 Porsche 944 with a 9" ADC, a Z1k and 144 BB600
cells. The motor is
connected to the original clutch and bell housing. The existing transaxle is
still in the rear.
Charging is courtesy of one of Rich's PFC-30s. All the cells are in the rear
where the gas tank
used to be. I installed a pair of air shocks to get the rear back up to level.
> Dave Cover and I had a little competition going. I can't recall all
> his times but we kept going back and forth for first and second place
> throughout the day.
I arrived a little late and was still unhooking the car when they called for
the driver walk thru.
IIRC, by the time I was ready to go, the others all had a turn at the course. I
wasn't really
paying too much attention to the times, I was just happy to be there with a
running car. One thing
about my car is that, right now, the weight distribution is less than ideal.
The front end is
light and the rear is heavy. All the weight over the rear axle makes for great
traction, too much
for me to put on a smoke show. With a light front end and a wallowing rear end,
it was very good
at screeching through the corners. In fact the whole course was a controlled
slide. The front ends
understeering was balanced by the rear end whipping around from the packs
momentum. But it was
FUN!
When I went to hook up to the spider to get a little charge time in, I was
unpleasantly suprised
to find that everyone but me uses a 3 prong plug. Rat's, I'd have to get by on
the charge I
brought with me. I even scrambled to try to make a 110 connection, but that
didn't work either. So
here I am, my pack getting weaker with each run, and Chip getting faster. I had
to get inspired or
I wouldn't be able to keep my lead.
I finally had a brainstorm and made two adjustments for my last run. First, I
remembered that I
had the tires over inflated to reduce rolling resistance. Actually, I think
Darrin came up with
that idea, but I quickly brought all four corners down to around 25 psi. Even
though auto cross is
all about corners, and his specialty is going straight, I thought, "What would
Wayland do?" The
answer was obvious, I needed tunes, loud tunes. Now his taste tends to be a
little new for me, so
I went with one of the classics. Black Sabbath, Paranoid.
> But he finally threw down the gauntlet and turned
> in a 28.433 beating my best time of 29.192.
Bingo! Even with a diminishing pack, that did the trick. Boy was that run fun.
I didn't care about
the drag strip tomorrow, this was a blast! Now, I crossed my fingers and hoped
Chip wouldn't run
again.
>I decided to throw him a
> curve and let the SCCA professional driver take the wheel of my car
> without Dave knowing. He screached the tires and was tearing up the
> course with the car and turned in a 27 second time.
Boy, was I depressed to see Chips car come screeching into the trap and beat me
again. How the
hell did he keep doing that? But wait, that's not Chip behind the wheel!
> Dave saw the timer and couldn't believe it. I had him going there for
> a couple minutes when he finally caught on. So he let the guy drive
> his Porsche and turned in a 26 second time. So he bettered both Dave
> and I by 2 seconds on our best runs.
But, you know Chip, we both forgot an important point. We let him drive our
cars, he owes us a
ride in his hot rod Boxster. Maybe we can collect next year.
Thanks again for all the work an event like this requires. I don't know if my
car will ever make
it to a drag strip, but you know it's going to autocross again.
Dave Cover
--- End Message ---
--- Begin Message ---
On Jun 5, 2007, at 7:34 AM, John Wayland wrote:
As a stand-alone, Roger's point on this is partially true. The
problem with Roger's take on this though, is that he has
'conveniently' overlooked the context of this entire
discussion...Guy's BMW conversion. In this heavy car, to get the
same DC torque at the wheels with the proposed AC system, he's
going to have to somehow, find a BMW rear gear set in the 7:00
ratio range. Roger, do you have a handle on the whereabouts of
these mythical super-low differential gears that will fit his BMW's
rear end? If Guy could find a set (doubtful) they'd surely be $2000
just for the ring and pinion...more cost, just to justify AC. Keep
in mind, that while Guy is shopping around for these costly gears,
he'll still have to now change his simple, easy, and low cost
flooded cell pack to a more expensive AGM pack with 25-30 BMS regs
for each battery, too.....again, AC makes the cost of Guy's
conversion go through the roof.
Yea, but do you expect that 1st gear will be used with a the proposed
144 volt system and an ADC 9 inch motor? The suggested zilla setup
(1000 amp motor limit, 500 amp battery limit to keep GC batteries
alive) would provide maximum torque up to around 63 motor volts. What
rpm is a 9 inch turning at 63 volts and 1000 amps? I suspect its to
low to make 1st gear useful. With the higher revving AC system a most
of the needed extra multiplication could be provided by using 1st.
I'm going to take a WAG at the rpm range the proposed system would
get full torque out of the 9 inch motor based on the following:
1. You know the ADC 9 inch, I've never used one - you say about 300
ft/lb. of torque (previous post in this thread) so I will use that as
the torque at 1000 amps.
2. At 1000 amps and 63 (motor) volts the motor is about 80% efficient
- I suspect I'm being generous.
3. The GC batteries will sag to 1.75 vpc at 500 amps (that is my
experience.)
4. Power in will equal power out minus efficiency losses.
Conclusion: I get 300 ft/lb. of torque (1000 motor amps) up to about
1200 rpm.
This is a bit of my experience for Guy. GC (golf cart) batteries do
not add up to "good" performance in any vehicle. Even with 1/2 the
weight of the converted car in GC batteries you will have less than 1
horsepower available per 40 lb. of vehicle weight (a Geo Metro is
better.) With 1/3 of the converted vehicle weight in GC batteries
performance will be in the range of an old 36 HP Beetle. (I've owned
2 of them, they are fine but in no way "performance".) Sorry for
being a downer on this point; I don't want to create false expectations.
Paul "neon" G.
--- End Message ---
--- Begin Message ---
Hmm. Looks like dual 9's might be better for my desires. NetGain sells
the TransWarp in 9" and 11" now, so I can buy a TransWarp 9", bolt it
up, get running, then bolt a standard Warp 9" on later when I feel the
need for speed. It's $600 more, but probably more than 2X the
performance.
My commute is only 15 miles RT per day, so the 20-30 need is just so I
can run an errand now and then.
Thanks for the pointer to the 240SX. I'd found his main home page
before, but I don't remember seeing such a concise list of the
drivetrain before. It does look like what I want. Not sure I can stay
that low on my curb weight though.
--Ian
On 6/5/07, MIKE WILLMON <[EMAIL PROTECTED]> wrote:
2000A from a Zilla to a TransWarp9 direct drive to a 3.91 rear end might get
you fairly decent acceleration.
With my truck and a 1000 amps to the single Warp9 with the Tranny in 4th (1:1) to a
3.6something rear gear the accelerations was not dog slow, but I wouldn't want to
have to start off like that all the time. Starting off in 3rd was quite acceptable
when able to pull 1000 amps. However with 2000 amps on tap the single 9" would
probably give you a fairly reasonable acceleration *direct drive* especially with
your taller rear gear and presumably lighter weight than mine.
As far as RPM goes between the 11" and 9" Netgains curves list the 11" at 4000 rpm
and the 9" at 5600 rpm. Most likely the motors will safely exceed those RPM's slightly, but I
wouldn't count on it for warranty work.
2000 amps to a TransWarp11" will make you launch like a dragster but at 4000
rpm would top you out at around 67 mph.
2000 amps to the TransWarp9" will accelerate you fairly quickly but at 5600 rpm
you would be up to 94 mph.
Both assume 3.91 rear end and 22" tall tires.
Look at the motor curves on the Netgain site and you can see that at the same currents,
say 300 ish amps the 11" puts 80 lbs-ft and the 9" puts 60 lbs-ft.
approximately the same 25 horsepower though.
Or at the same rpm of 4000 ish RPM, the torque from the 9" is about 12 lbs-ft and
the 11" is down to 10 lbs-ft.
Now these are taken at 72V and presumably you will be hitting them hotter than
this. But the relative ratios will be about the same for making comparisons.
Mike,
Anchorage, Ak
----- Original Message -----
From: Ian Jordan <[EMAIL PROTECTED]>
Date: Tuesday, June 5, 2007 2:28 pm
Subject: Re: Another BMW conversion (1994 318ti)
To: ev@listproc.sjsu.edu
> I'm really fine with a car that gets to 70 quick and then just runs
> out of RPM/voltage/whatever. Not interested in total quarter mile
> times, I just want a lot of oomph down low at normal 0-50 MPH city
> speeds.
>
> Is the tradeoff between a 9" and 11" motor the RPM limit? Can you spin
> a 9" faster than an 11"?
>
> I am sort of considering going to a single Transwarp 9" right now
> knowing I could bolt on a normal Warp 9 at any time, once I have the
> basics down.
>
> --Ian
>
> On 6/5/07, MIKE WILLMON <[EMAIL PROTECTED]> wrote:
> > I think that the RPM hit you'd take using the Netgain 11" might
> justify the two 9"s if you were going to going for 1/4 mile times.
> Although you would have to implement a series parallel switching
> to make most efficient use of the battery power.
> >
> > Of course if you won't be racing, the 11" motor may just be
> simpler to deal with.
> >
> > You can get both the 9" and 11" in the TransWarp configuration now.
> >
> > Mike,
> > Anchorage, Ak.
> >
> > ----- Original Message -----
> > From: Ian Jordan <[EMAIL PROTECTED]>
> > Date: Tuesday, June 5, 2007 1:14 pm
> > Subject: Another BMW conversion (1994 318ti)
> > To: ev@listproc.sjsu.edu
> >
> > > I'm thinking of converting a 1994 BMW 318ti hatchback to an EV,
> but> > I'm a newbie to the EV stuff. Can someone glance at my plan
> and see if
> > > it seems possible?
> > >
> > > 1994 BMW 318ti. Curb 2850, Gross 3900, RWD.
> > >
> > > Range 30 miles (I could maybe live with 20)
> > > 0-60 in 6.0 sec or less
> > > 75+ MPH top speed
> > >
> > > Direct drive, no transmission. 3.91 rear end gives me 75MPH @ 4000
> > > RPM. I can get rear ends from 2.93-5.85 easily.
> > >
> > > NetGain TransWarp 11" motor (or would two 9" be better for my
> plan?> > Cost is about the same)
> > >
> > > Zilla 2K controller
> > >
> > > Flooded batteries, no idea how many, or what size.
> > >
> > > Will I be able to get my performance requirements with this setup?
> > >
> > > Can you run an advanced timing motor like the Warps in reverse in
> > > order to get reverse out of a direct drive system? I know you
> can't> > run them full time without messing with the timing, but is
> it OK for
> > > very low duty cycle stuff like reverse?
> > >
> > >
> >
> >
>
>
--- End Message ---
