Electric motor with no tranny for conversion

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Re: Electric motor hybred something.

Peter Shabino
If you need a example of Mark's suggestion look at any Pontiac Fiero. The factory engine/tranny setup in those is from a different FWD vehicle installed in the rear as a mid engine steering knuckles and all (tied off to the frame). We have always joked about adding a second rack and pinion to the card and have 4 wheel steering for easy parallel parking and wicked lane changes. :)

Later,
Peter



> From: [hidden email]
> To: [hidden email]
> Date: Fri, 23 May 2008 08:06:33 -0600
> Subject: Re: [EVDL] Electric motor hybred something.
>
>
> Did you consider mounting any of the front wheel drive transmissions in the
> rear of the car?
>
> Mark Grasser
>
>
> Just about did this method back in 1985 before I experiment with a with a
> v-6 engine that can drive the vehicle either by itself, or as a helper to
> the electric motor or electric power only.  The engine was place in front of
> a GE-11 motor which was couple to the input shaft of the motor with a In and
> Out clutch.
>
> It work great for climbing these mountain roads, but city driving not so
> great, because the average mpg drop and using it as a electric only, the
> range was cut in half because of the weight.
>
> So I came across a front wheel drive Buick with only 900 miles on it that
> the rear of the vehicle was gone.  I was thinking of getting another new
> front wheel drive Buick and connect the two back to back.
>
> Have one driven by electric and the other end driven by the engine. I Either
> one can become a helper while the other becomes the prime mover.
>
> We had one guy did this with two Chevy pickups, but left the engines in
> place and the driving direction is forward either in either direction,
> having two steering wheels, controls and etc. Had the two boxes connected
> together at the tail gate for a very large cargo space.
>
> Now if I did that, I could get 80 batteries in there and use two 13 inchers
> and to get over the rocks.
>
> Roland
>
>
>  
>
> _______________________________________________
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Re: Electric motor with no tranny for conversion

Adrian DeLeon
In reply to this post by chazersize
> Seems to depend where you look ;^>

Haven't checked the Cafe Electric website in a while... I wonder if the  
lower numbers could be for light vehicles without water cooling? I suppose  
someone could actually bother to ask Otmar.

> What sort of EV do you have (weight, voltage, etc.)?
http://www.evalbum.com/776

It's an '87 VW Cabriolet with Impulse9, Z1k-LV, and 114V of T-105  
batteries. Typical weight with passengers is 3,600 pounds! I'll try some  
hills in 3rd and 4th to see what the difference is. I could probably  
calculate the difference if I could find my original design spreadsheet.

-Adrian

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Re: Electric motor with no tranny for conversion

Roger Stockton
Adrian DeLeon wrote:

> Haven't checked the Cafe Electric website in a while... I
> wonder if the lower numbers could be for light vehicles
> without water cooling?

I doubt it, since in both places it states a "coolant" temp of 50C.  One of the other specs refers to a "heatsink" temp of 50C instead.  It looks very much to me as if the specs changed at some point and were only updated in one of the two places.  We just don't know if they increased or decreased.

> I suppose someone could actually bother to ask Otmar.

Ask the manufacturer?  Too obvious ;^>

> > What sort of EV do you have (weight, voltage, etc.)?
> http://www.evalbum.com/776
>
> It's an '87 VW Cabriolet with Impulse9, Z1k-LV, and 114V of
> T-105 batteries. Typical weight with passengers is 3,600
> pounds! I'll try some hills in 3rd and 4th to see what the
> difference is. I could probably calculate the difference if I
> could find my original design spreadsheet.

Be careful; I suspect that the 400A current you were reporting is battery side, not motor current.  Your 'Zilla may survive but your motor may be wounded as a result of the experiment since it is not designed to take these kinds of currents for long, and motor current will be greater than or equal to the battery current.

If you have a Palm or other means of logging/monitoring the 'Zilla data output, it might be safer to just see what the 'Zilla reports its temperature and motor current to be, and see how the temperature behaves over the course of your commute and/or this 400A+ hill.

Thanks again for the datapoint!

Cheers,

Roger.

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Re: Electric motor with no tranny for conversion

Roger Stockton
In reply to this post by Tim Medeck
Tim Medeck wrote:

> There is no room for a transmission in the Sunrise-EV2. With
> the central battery tunnel, and the differential rotated 180
> degrees so the motor points toward the rear of the car, it is
> still a tight squeeze to get everything crammed in the
> available space.

Understood, but this is a design decision.  Remember, the vehicle was designed to be FWD and it has been a design decision to convert it to trannyless RWD.  My observation is merely that a tranny with a smaller motor and controller would very likely be cheaper overall for a given level of performance.  As far as space goes, bear in mind that a RWD or FWD transaxle in place of the chosen RWD IRS diff is a space-efficient possibility.

There are lots of reasons for doing something other than cost, and I appreciate that it is these other considerations that justify the decision to go for a trannyless RWD setup in the Sunrise-EV2.

> > Even in the case of a trannyless 'Vette, it still doesn't
> > seem to make financial sense.
>
> Yeah, but cost is not the sticking point. SPACE for the parts
> is the problem.

Understood.  My point is not that there are not valid reasons for going trannyless, just that even with a missing tranny to start with it is not necessarily cheaper to go trannyless (which is what appeared to be being suggested).

> > Well, why on earth would someone convert a sportscar into
> > an EV with econobox performance? ;^>
>
> Michael is building this car to promote EVs. He is going to
> take it to a lot of "Green" shows and even Corvette shows and
> meets. He is willing to sacrifice driving range so that he
> can present an EV to the public that is NOT a cheese wedge or
> econobox.

I'm not sure that is was your intent, but you are just making my point. ;^>

I wasn't suggesting that Michael's 'Vette has econobox performance (with a TW11 and Z2K that outcome would make a grown man cry ;^), but rather addressing Lee's suggestion that these parts in the Mustang conversion would result in a rather quick EV.

Given Micheal's intention, I think he has made good decisions about the performance level of his conversion.  My personal belief is that someone who chooses a sportscar donor for a conversion does the cause no favour if they give it only econobox performance.

> This is his choice and I think that he should applauded for
> it, not vilified.

Absolutely!  This discussion is NOT about Michael or his 'Vette; it was offering guidance to someone contemplating a trannyless Mustang conversion.  Lee offered Michael's 'Vette as an example of the performance level a trannyless conversion can offer.

> > I suspect that if one went with a pair of 9's (e.g one
> > Transwarp and one Warp) that a Z1K with series/parallel would
> > be adequate in a trannyless (heavy) sportscar.
>
> Again, space is the issue. With conversions, or even scratch
> built  EVs ,it comes down to space, space, space.

Agreed.  Just bear in mind that space constraints come in different shapes and sizes.  Michael seems to be more constrained by motor length, but others might find an 11" too large in diameter to squeeze into a drivetrain hump, and a pair of 8's or 9's coupled end-to-end could provide similar power handling in a form factor more compatible with the space constraints.

Cheers,

Roger.

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Re: Electric motor with no tranny for conversion

Roger Stockton
In reply to this post by Lee Hart
Lee Hart wrote:

> We considered it; but the Sunrise is designed to be an EV;
> there isn't any place for a transmission.

Sorry, but I don't accept this statement.  The Sunrise was designed as a FWD EV, and had a transaxle with a fixed reduction (i.e. a single-speed tranny).  It was a design decision to convert this to a RWD trannyless configuration for the EV2 re-incarnation.

There may not be any place for a conventional RWD tranny because the car was designed to be FWD, but being designed as an EV does not automatically equate to having to be designed without space for a tranny.

> The car we are using as a donor only comes with a large heavy
> automatic transmission. It doesn't have a locking torque
> converter, and is heavier than the motor itself, and so a
> poor choice for an EV.

Understood.  My suggestion was not to use whatever tranny happens to be in the donor used for the suspension, but to source a common tranny from another donor if required.

(I know, this conflicts with the goal of using a single donor vehicle, but my point has only ever been that including a tranny is likely to be *cheaper* for a given performance level than upsizing the motor and controller to go trannyless.  Of course there may be other considerations that trump any cost advantage that including a tranny might offer.)

> We're using a WarP 9" motor, which is no bigger than what
> most EV conversions use. Rather than upsizing the motor,
> we're downsizing the car. The Sunrise EV2 is considerably
> lighter than a regular car.

Well, I suppose we'll be sure of that once you have one finished ;^>

I suspect that it may not come out all that different in curb weight when it is finished, though more of that weight may be in batteries.  More weight in batteries may help the range, but the drivetrain can't tell the difference between being asked to move 1000lbs of batts and 1000lbs of car or 500lbs of batts and 1500lbs of car.

> > If the 'Vette doesn't have a tranny at present, then *any* suitable
> > Chevy or Ford, etc. tranny could be used.  No need to fork out big
> > bucks for a 'Vette specific 5 or 6 speed when we know the
> > EV is likely to use only a couple of gears anyway.
>
> The Corvette has a unique engine, transmission, and
> differential layout.
> None of them are interchangeable with any other GM vehicles.

I don't follow you at all.  I don't recall if you mentioned what year the 'Vette is, but the 84-88 'Vette tranny I suggested clearly is compatible with any common front-engine RWD configuration.  It has an input shaft at one end to couple to the engine, and a splined output shaft at the other to accept a standard driveshaft yoke.  The shifter location might make use of a top-shifter tranny more of a challenge, but any side shifter model could be adapted.

> The 'Vette manual transmission is stupefyingly expensive.
> Michael saved over $2000 by buying one with an automatic transmission.

So, he could have bought a manual tranny donor for $2K+ more, or could have bought a *new* manual tranny for $3K+, but instead spent almost $5K more to go trannyless?

Tim has explained the space rather than cost was the driver here, so I appreciate why Michael build the car as he did, but you are quite convincingly making the point that cost would not have been a very good reason for going trannyless in this case.

> One snag we didn't foresee; 'Vette's come with two different
> Dana differentials. One of them is easy to get other gearsets
> for; the other one has a very limited selection. Naturally,
> Michael's has the wrong one. Thus, we're stuck with the
> 2.73:1 ratio until we can find the other differential.

Oooohh, the cost argument just tilted *waaay* in favour of buying the manual tranny donor instead. ;^>  The 'Vette diff *is* unique and expensive, and now he has to not only buy a gearset but another diff.

Cheers,

Roger.

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Re: Electric motor with no transmission for conversion

Lee Hart
In reply to this post by Mark Grasser
Mark Grasser wrote:
> Lee,
> Not to keep pushing the transmission idea but did you consider a transaxle,
> granted a little more expensive than your usual transmission but uses barely
> any extra space. Porsche 944 and 928, the new corvettes also have them. Did
> you consider mounting any of the front wheel drive transmissions in the rear
> of the car?

Yes, we considered that, too. The original Sunrise has a transaxle from
a Geo Metro. This is a rather weak part, but they only had a 50kw peak
drive motor/controller. We wanted something stronger and more powerful,
but there wasn't much room under the hood. Trying to squeeze in a bigger
transaxle and/or a bigger motor would be a serious challenge.

So, we switched to rear wheel drive to get more room. (It also had the
advantage of shifting the battery weight forward, for normal car balance
and handling). I liked the idea of a front wheel drive package in the
rear, because the transaxle provided the needed reduction without new
gears, and the transverse ring/pinion is more efficient than a hypoid
ring/pinion. But, we didn't find any that we really liked.

We wound up choosing the T'bird rear end for a number of reasons. They
are common (over a million produced), inexpensive (these cars are not
popular), strong (used in 4500+lbs GVWR vehicles), and the Ford 8.8"
differential is a common racing part (lots of aftermarket parts).

There may be better choices. One good thing about our chassis is that
builders can try other setups if they like.
--
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

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Re: Electric motor with no tranny for conversion

Richard Marks
In reply to this post by Adrian DeLeon
Adrian,
    I am stepping into the middle of this and have just registered to join
the forum.  Otmar told me all of his controllers need to be water cooled.  I
had asked if it was necessary for a 1K running at less than 350A.  He said
it was necessary.  I suspect that he has a heat sink that is contained in
his cooling chamber and he runs water over it to cool it.  This is very
effective and much more effective than air cooling.  His recommended pump is
only 20W, so it is not a big hit on your efficiency.
    Richard
Best Regards,

            Richard W. Marks

            President

            EnVironmental Transportation Solutions, LLC

            313-717-4321

            www.EcoVElectric.com

            http://EcoVElectric.blogspot.com

----- Original Message -----
From: "Adrian DeLeon" <[hidden email]>
To: <[hidden email]>
Sent: Friday, May 23, 2008 1:08 PM
Subject: Re: [EVDL] Electric motor with no tranny for conversion


>> Seems to depend where you look ;^>
>
> Haven't checked the Cafe Electric website in a while... I wonder if the
> lower numbers could be for light vehicles without water cooling? I suppose
> someone could actually bother to ask Otmar.
>
>> What sort of EV do you have (weight, voltage, etc.)?
> http://www.evalbum.com/776
>
> It's an '87 VW Cabriolet with Impulse9, Z1k-LV, and 114V of T-105
> batteries. Typical weight with passengers is 3,600 pounds! I'll try some
> hills in 3rd and 4th to see what the difference is. I could probably
> calculate the difference if I could find my original design spreadsheet.
>
> -Adrian
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Re: Electric motor with no tranny for conversion

EVDL Administrator
In reply to this post by Roger Stockton
On 23 May 2008 at 11:33, Roger Stockton wrote:

> There may not be any place for a conventional RWD tranny because the car was
> designed to be FWD, but being designed as an EV does not automatically equate
> to having to be designed without space for a tranny.

Lee would obviously know more about this than I, but I think the Sunrise was
originally designed for the Solectria/Brusa fixed-ratio AT1200 transaxle
with integrated AC motor, mounted in the front and driving the front wheels.
 A similar item is still available under the Solectria marque and Brusa
appears to be developing a new one.  If Lee's mods haven't made it
impossible to fit, that would certainly be an option.

But then a single-speed transaxle and AC induction motor isn't what you're
after, is it?  You were thinking of a plain vanilla series DC motor, no?

David Roden - Akron, Ohio, USA
EVDL Administrator

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Re: Electric motor with no tranny for conversion

Morgan LaMoore
In reply to this post by Roger Stockton
On Fri, May 23, 2008 at 1:33 PM, Roger Stockton <[hidden email]> wrote:
> Lee Hart wrote:
>
>> We considered it; but the Sunrise is designed to be an EV;
>> there isn't any place for a transmission.
>
> Sorry, but I don't accept this statement.  The Sunrise was designed as a FWD EV, and had a transaxle with a fixed reduction (i.e. a single-speed tranny).  It was a design decision to convert this to a RWD trannyless configuration for the EV2 re-incarnation.

The original used NiMH batteries, and now they're trying to get 60
miles range with lead batteries. Much more space is required for
batteries, so less space is left for other components.

> There may not be any place for a conventional RWD tranny because the car was designed to be FWD, but being designed as an EV does not automatically equate to having to be designed without space for a tranny.

It wasn't designed with space for a standard RWD tranny. Are there
readily available, durable, cheap FWD transaxles that can easily mount
to a series-wound DC motor? If not, this doesn't seem like a good
option for the Sunrise.

Yes, you've emphasized that the tranny is the cheaper solution. I
don't think anyone is arguing with you on that point. As you said,
though, there's other reasons to go trannyless.

-Morgan LaMoore

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Re: Electric motor with no tranny for conversion

Roger Stockton
In reply to this post by EVDL Administrator
David Roden wrote

> Lee would obviously know more about this than I, but I think
> the Sunrise was originally designed for the Solectria/Brusa
> fixed-ratio AT1200 transaxle with integrated AC motor,
> mounted in the front and driving the front wheels.

Lee's website states that the original Sunrise used '94 Metro and Neon running gear (Metro in the front, Neon in the rear), and that it used a 50kW air-cooled AC motor with a Metro (presumably from the same '94 as the suspension bits) transaxle locked in 2nd gear.

> A similar item is still available under the Solectria marque
> and Brusa appears to be developing a new one.  If Lee's mods
> haven't made it impossible to fit, that would certainly be an option.

Lee's webpage (or an email of his?) has stated that he wants RWD to allow a longer battery box to fit that is easier to remove from the car.  He has indicated that he likes and considered using a transaxle, but couldn't find one he liked (the Metro transaxle was considered too weak, especially given that the EV2 version of the Sunrise is planned to have a curb weight well over the original Sunrise's GVWR).

I believe Lee's intention is for the EV2 to allow each builder to choose whatever drivetrain they wish to install (AC or DC), but I'm not sure changing the EV2 back to FWD would be feasible unless the individual builder was prepared to do a bunch of engineering work to undo much of the EV2 changes.

Cheers,

Roger.

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Re: Electric motor with no tranny for conversion

Lee Hart
In reply to this post by Roger Stockton
Roger Stockton wrote:
>> We considered it; but the Sunrise is designed to be an EV; there
>> isn't any place for a transmission.

> Sorry, but I don't accept this statement. The Sunrise was designed as
>  a FWD EV, and had a transaxle with a fixed reduction (i.e. a
> single-speed tranny).

The Sunrise is a "cab forward" design. The passenger space is pushed far
forward, with a very short low hood and very small front overhang. It
used a Geo Metro front transaxle and Solectria AC24 50kw induction
motor. These components are very small and light.

But, it was a 2979 lbs GVWR car. That's a mighty small drive system for
this much weight. I don't know of any other full-size car with this
small a drive package. Acceleration was weak; 0-60 mph in 17 seconds.

One of our goals in the Sunrise EV2 is to significantly improve on this.
We've doubled the power to 100kw, which means we also need a stronger
transaxle. Moreover, there may be builders who want to go even farther;
a Sunrise EV2 with a Zilla Z2K and 300vdc pack can hit 600kw and be a
serious contender on the drag strip!

We couldn't find a transaxle that would fit in front and handle this
kind of power. So, we changed it to rear wheel drive. The design of the
Sunrise has a lot more room in back.

> being designed as an EV does not automatically equate to having to be
>  designed without space for a tranny.

Agreed. But this particular car was designed without sufficient space
for a normal-sized transmission.

One could start with a blank sheet of paper and design an EV that did
have space for a transmission. But in the cases I know of, the designers
chose instead to make it a single-speed (transmissionless) design.

> my point has only ever been that including a tranny is likely to be
> *cheaper* for a given performance level than upsizing the motor and
> controller to go trannyless.

It all hinges on what you have to pay for that transmission. Not just
the cost of the transmission itself; but also the space, weight,
efficiency, and other factors.

Also, it depends on your performance requirements. The wider the range
of torques and speeds you need/want, the better a transmission looks. If
I live in the great plains and never drive over the speed limit,
transmissionless is hard to beat. If you live in the mountains and like
to go drag racing, then having a transmission is the winner.

> I suspect that it may not come out all that different in curb weight
> when it is finished, though more of that weight may be in batteries.

Right. We are building a efficient car that can carry more than its own
weight in batteries. That's the only way to get excellent range even
with affordable batteries.

>> The Corvette has a unique engine, transmission, and differential
>> layout. None of them are interchangeable with any other GM
>> vehicles.

> I don't follow you at all.  I don't recall if you mentioned what year
> the 'Vette is, but the 84-88 'Vette tranny I suggested clearly is
> compatible with any common front-engine RWD configuration.

It's a 1987 Corvette. I was told that it uses special transmissions,
different from every other GM product. The internals may be the same,
but the externals are certainly unique. For example, there is no
transmission mount; the rear of the transmission bolts to a huge
aluminum torque tube that extends to the differential.

> So, he could have bought a manual tranny donor for $2K+ more, or
> could have bought a *new* manual tranny for $3K+, but instead spent
> almost $5K more to go trannyless?

With transmission:
   $2000 premium for manual transmission Corvette
    $400 adapter plate and coupler
   $1975 Zilla Z1K-LV controller
   $1430 Netgain WarP 9" motor
   -----
   $5805 total

Without transmission:
   $3851 Zilla Z2K-LV controller
   $3825 Netgain TransWarP 11" motor
   -----
   $7676 total

So, Mike paid about $1871 more to go transmissionless. Some of this will
be recouped when he sells the automatic transmission that came with the car.

And as Tim said, there are other reasons besides financial for taking
this route (saved weight, more room for batteries, etc.).

>> One snag we didn't foresee; 'Vette's come with two different Dana
>> differentials. One of them is easy to get other gearsets for; the
>> other one has a very limited selection. Naturally, Michael's has
>> the wrong one. Thus, we're stuck with the 2.73:1 ratio until we can
>> find the other differential.

> Oooohh, the cost argument just tilted *waaay* in favour of buying the
> manual tranny donor instead.

Yes. Life always has its little surprises. :-( Then again, who knows
what the replacement will actually cost, and what he can get for the
present differential?
--
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

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Re: Electric motor with no tranny for conversion

Peter VanDerWal
>
> With transmission:
>    $2000 premium for manual transmission Corvette
>     $400 adapter plate and coupler
>    $1975 Zilla Z1K-LV controller
>    $1430 Netgain WarP 9" motor
>    -----
>    $5805 total
>

Where the heck do you get an adapter plate AND coupler for only $400?

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Re: Electric motor with no tranny for conversion

Roger Stockton
In reply to this post by Morgan LaMoore
Morgan LaMoore wrote:

> The original used NiMH batteries, and now they're trying to
> get 60 miles range with lead batteries. Much more space is
> required for batteries, so less space is left for other components.

Nope, not actually ;^>

Have a look at the Sunrise EV2 site. The EV2 increased the height and width of the battery box only slightly (0.5" wider and 1" taller) so that a wider variety of batteries would fit.  The big change has been to increase the length of the box by 12" (to 120" from 108").  This doesn't equate to "much more" battery space, but increasing the length of the battery box meant having to extend it either ahead of the front axle or further behind the rear axle (since the original box ran from just behind the front wheels to just behind the rear wheels).  Lee has stated that the original FWD configuration resulted in a bit more rearward weight bias than is desirable for good handling so the decision was to switch to a RWD arrangement.  With the drivetrain out of the way up front, the slightly longer battery box could be relocated to be entirely ahead of the rear axle.

> > There may not be any place for a conventional RWD tranny
> because the car was designed to be FWD, but being designed as
> an EV does not automatically equate to having to be designed
> without space for a tranny.
>
> It wasn't designed with space for a standard RWD tranny.

This *specific* vehicle wasn't. What I took exception to was the implication that *any* vehicle designed as an EV would not have space for a transmission.  The Sunrise, for instance *was* originally designed as an EV, with space for a FWD transaxle.

> Are
> there readily available, durable, cheap FWD transaxles that
> can easily mount to a series-wound DC motor? If not, this
> doesn't seem like a good option for the Sunrise.

The RWD configuration of the EV2 probably lends itself better to a rear or mid-engined transaxle, such as one from a VW or Porsche, etc.  As for FWD transaxles, the one behind the V6 in a '80 (IIRK) Chevy Citation that I punished in my teens held up very reliably.  This or a close cousin is likely the same as is found in the rear of the Fieros.  Not sure about the durability, but the transaxle out of a Dodge Caravan ought to be readily available.  I don't know about cheap, but I'd expect the transaxle out of a Honda Civic or Accord, etc. to be readily available and durable.  Similarly, one from a FWD VW could be a candidate.  Any of these mount easily to a series DC motor.

But, using any of these would result in the builder of a Sunrise EV2 having to source parts from two different donor vehicles, which is a big strike against it.

If Lee were to reconsider the tranny option, I think the biggest driver will be if he discovers that he really does need a Z2K without a tranny.  His website indicates he plans to use a 9" motor and Z2K-LV, however, the Caf? Electric site no longer lists the -LV model and the $2000 premium for the Z2K-HV could pay for a fairly decent tranny.  I don't know of any other 2000A-capable DC controllers, so relying on a single source for the controller might be more risky than using a tranny so that anything from a 500A Curtis to a Z2K could be used.

But, the intent of the Sunrise EV2 is to offer a kit that individual builders can customise as they see fit should they wish to try a different configuration than Lee's prototype.

Cheers,

Roger.



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Re: Electric motor with no tranny for conversion

Roger Stockton
In reply to this post by Lee Hart
Lee Hart wrote:

> > being designed as an EV does not automatically equate to
> > having to be designed without space for a tranny.
>
> Agreed. But this particular car was designed without
> sufficient space for a normal-sized transmission.

Agreed; I just couldn't let the suggestion that *all* EVs would necessarily be designed this way.

> One could start with a blank sheet of paper and design an EV
> that did have space for a transmission. But in the cases I
> know of, the designers chose instead to make it a
> single-speed (transmissionless) design.

And we know how well the Tropica worked out, don't we? ;^>

> If you live in the mountains and like to go drag racing, then
> having a transmission is the winner.

Even under far more modest usage, the tranny can come out the winner.  For instance, one lives in a hilly area such as Seattle or SF and also need to be able to get on the freeway for part of their commute.

> It's a 1987 Corvette. I was told that it uses special
> transmissions, different from every other GM product. The
> internals may be the same, but the externals are certainly
> unique. For example, there is no transmission mount; the rear
> of the transmission bolts to a huge aluminum torque tube that
> extends to the differential.

Was there a mount for the 11" motor? How about battery boxes? ;^>

I appreciate that the 'Vette used a tranny not found in any other GM vehicle, but the picture of the tranny for the 84-88 'Vette on the site I referenced shows a basically very standard manual transmission package.  It still connects to the diff with an ordinary driveshaft, so any other manual tranny could be used with varying amounts of fabrication to make brackets or other bits to adapt the shift linkage to the stock location and the tranny to the driveshaft and perhaps to the torque tube.

> With transmission:
>    $2000 premium for manual transmission Corvette
>     $400 adapter plate and coupler
>    $1975 Zilla Z1K-LV controller
>    $1430 Netgain WarP 9" motor
>    -----
>    $5805 total
>
> Without transmission:
>    $3851 Zilla Z2K-LV controller
>    $3825 Netgain TransWarP 11" motor
>    -----
>    $7676 total
>
> So, Mike paid about $1871 more to go transmissionless.

It appears he was fortunate in getting the lower-cost Z2K-LV; it is no longer listed by Café Electric.

It also appears that he doesn't plan to ever drive in reverse, since he didn't have to invest in a reversing contactor ($570), and you haven't included even the cost of the new gearset for the rear end ($400).  It seems his cost was likely nearer to $2841 with these incidentals included, and someone trying to copy his 'Vette today would have to use the more expensive Z2K-HV (Café Electric no longer lists the Z2K-LV) and so pay $3665 more than converting a manual tranny donor.

In reality the cost difference is likely less since you've budgeted very little for the adapter plate and coupler.  But the point was only that going trannyless didn't save any money.

> And as Tim said, there are other reasons besides financial
> for taking this route (saved weight, more room for batteries, etc.).

Of course, and I don't dispute that those are very valid reasons.

Cheers,

Roger.

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Re: Electric motor with no tranny for conversion

Lee Hart
In reply to this post by Peter VanDerWal
>> With transmission:
>>    $2000 premium for manual transmission Corvette
>>     $400 adapter plate and coupler
>>    $1975 Zilla Z1K-LV controller
>>    $1430 Netgain WarP 9" motor
>>    -----
>>    $5805 total

Peter VanDerWal wrote:
> Where the heck do you get an adapter plate AND coupler for only $400?

Just guessing. No one has one for a Corvette to get a price. I used a
low-ball guess so as not to put my "thumb on the scale" to favor the
transmissionless route.

--
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

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Re: Electric motor with no tranny for conversion

Lee Hart
In reply to this post by Roger Stockton
Roger Stockton wrote:
> I believe Lee's intention is for the EV2 to allow each builder to
> choose whatever drivetrain they wish to install (AC or DC), but I'm
> not sure changing the EV2 back to FWD would be feasible unless the
> individual builder was prepared to do a bunch of engineering work to
> undo much of the EV2 changes.

It would be a lot of work to go back to FWD; but the original Sunrise
shows you how to do it; there is a model to copy. The main challenge is:

  - Do you stick with the lightweight parts Solectria used?
    If so, you'll have to find lightweight batteries or suffer from
    short range.

  - Do you redesign it for heavier duty parts from some other FWD car?
    If so, you'll have to find something compact enough to fit.
--
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

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Re: Electric motor with no tranny for conversion

Lee Hart
In reply to this post by Roger Stockton
Roger Stockton wrote:
>> One could start with a blank sheet of paper and design an EV
>> that did have space for a transmission. But in the cases I
>> know of, the designers chose instead to make it a
>> single-speed (transmissionless) design.

> And we know how well the Tropica worked out, don't we? ;^>

The Tropica was not very well designed. It had two A89 motors, which are
too small for an EV even with a transmission. And, it had a 72v pack,
which was too low a voltage for these motors.

> Was there a mount for the 11" motor?

No; he made his own.

> How about battery boxes? ;^>

No, he made his own there as well. It appears that no one has converted
a Corvette of this vintage, so it was a venture into unexplored territory.

> I appreciate that the 'Vette used a tranny not found in any other
> GM vehicle, but the picture of the tranny for the 84-88 'Vette on the
> site I referenced shows a basically very standard manual transmission
> package. It still connects to the diff with an ordinary driveshaft,
> so any other manual tranny could be used with varying amounts of
> fabrication...

I would guess this to be true for the insides; but the transmission
case, drive shaft, differential, and torque tube are all specific to the
'Vettes. The Corvette transmission has no mounts to the frame at all. It
mounts to the engine via the bell housing in front, and to the torque
tube in back. The torque tube is actually a huge U-shaped beam that
surrounds the drive shaft and carries the load all the way back to the
differential.

>> ... So, Mike paid about $1871 more to go transmissionless.

> It appears he was fortunate in getting the lower-cost Z2K-LV; it is
> no longer listed by Café Electric. It also appears that he doesn't
> plan to ever drive in reverse, since he didn't have to invest in a
> reversing contactor ($570), and you haven't included even the cost
> of the new gearset for the rear end ($400).

The $3851 price *includes* the reversing contactors.

I didn't include a new gearset because he didn't buy one. He doesn't
think it's necessary yet. I think he will change his mind on this later. :-)

--
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

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Re: Electric motor with no tranny for conversion

Roger Stockton
Lee Hart wrote:

> The Tropica was not very well designed. It had two A89 motors, which are
> too small for an EV even with a transmission. And, it had a 72v pack,
> which was too low a voltage for these motors.

Yes, I was somewhat tongue-in-cheek observing that just because some EVs are built without trannies doesn't automatically make it a good idea or successful.

I think it very arguable that a pair of A89's driving through a multispeed tranny would have been much better even with the same 72V pack.  This would have allowed for improved hillclimbing and acceleration without sacrificing top speed.

> > Was there a mount for the 11" motor?
>
> No; he made his own.
>
> > How about battery boxes? ;^>
>
> No, he made his own there as well. It appears that no one has converted
> a Corvette of this vintage, so it was a venture into unexplored territory.

I can't tell if you missed the sarcastic humour I intended or not ;^>

Of course, he made these himself!  Just as he would have had to make his own mounting brackets and adapt a shift linkage in order to use a non-Vette tranny.  Offering the fact that the 'Vette didn't have a rear mount for the tranny as an excuse for not being able to use a non-Vette tranny is really grasping at straws ;^>

> > I appreciate that the 'Vette used a tranny not found in any other
> > GM vehicle, but the picture of the tranny for the 84-88 'Vette on the
> > site I referenced shows a basically very standard manual transmission
> > package. It still connects to the diff with an ordinary driveshaft,
> > so any other manual tranny could be used with varying amounts of
> > fabrication...
>
> I would guess this to be true for the insides; but the transmission
> case, drive shaft, differential, and torque tube are all specific to the
> 'Vettes.

No, no, no, the picture I refer to is of the outside of a fully assembled 'Vette transmission.  The insides are irrelevant.  The differential is irrelevant.  The driveshaft is somewhat relevant; the picture I refer to also shows the driveshaft yoke by which this driveshaft connects to the tranny output shaft.  This confirms that the driveshaft is conventional in design, and uses a U-joint between the shaft and yoke such that a yoke compatible with the spline on any RWD tranny can be substituted for the original 'Vette yoke if necessary.

> The Corvette transmission has no mounts to the frame at all. It
> mounts to the engine via the bell housing in front, and to the torque
> tube in back. The torque tube is actually a huge U-shaped beam that
> surrounds the drive shaft and carries the load all the way back to the
> differential.

I understand.  Most RWD trannies I've seen have a tailshaft housing that bolts on; these bolts could provide a convenient means of attaching an adapter plate to the output end of the tranny to allow it to bolt up to the 'Vette torque tube.  This then supports the rear of the tranny as originally intended.  The bellhousing on the front couples the tranny to the motor via the usual adapter plate.  Finally, since the motor ends up somewhere in the vicinity of the original engine mounts, some sort of crossmember can be fabricated to allow the motor and front of the tranny to be supported as originally intended.  It is all very doable.  The greatest challenge is adapting the tranny to use a 'Vette shifter or to at least locate the shifter in the stock 'Vette location.

Again, I appreciate that there are reasons why it was a good idea to convert the vehicle as was done, but there *were* feasible alternatives that could have allowed a tranny to be used for no more money, and possible less, and without sacrificing performance.

Cheers,

Roger.




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Re: Electric motor with no tranny for conversion

Lee Hart
Roger Stockton wrote:
> I was somewhat tongue-in-cheek observing that just because some
> EVs are built without trannies doesn't automatically make it a good
> idea or successful.

I agree; one data point does not make a curve. But essentially *all* EVs
designed from scratch have no transmission. The exceptions are the rare
ones.

> I think it very arguable that a pair of A89's driving through a
> multispeed tranny would have been much better even with the same 72V
> pack.  This would have allowed for improved hillclimbing and
> acceleration without sacrificing top speed.

Again, I agree. If you have undersized motors or controllers, a
transmission will let you get more out of them.

 >> he made his own motor mount... he made his own battery boxes.

> I can't tell if you missed the sarcastic humour I intended or not ;^>

Good! :-)

> Of course, he made these himself!  Just as he would have had to make
> his own mounting brackets and adapt a shift linkage in order to use a
> non-Vette tranny.  Offering the fact that the 'Vette didn't have a
> rear mount for the tranny as an excuse for not being able to use a
> non-Vette tranny is really grasping at straws ;^>

Hmm... you need to look at the situation under a 'Vette. The frame
doesn't come anywhere near the transmission. The steel frame rails are
way out in the rocker panels, about 5 feet apart, and the fiberglass
floor dips down close to the road between them. The closest frame to the
rear is 3 feet away, at the differential. The closest frame in front is
about 2 feet forward, at the engine mounts.

Chevy used the engine to mount the front of the transmission, and the
torque tube to mount the rear of it.

Michael chose to make a 5 foot wide piece of 2" x 4" steel U-channel,
with two vertical pieces on each side of the motor, diagonally braced to
the main piece, like this. ___/|__|\___ The motor sat in the center. He
bolted it to the steel U-channel with the field mounting bolts. The
U-channel reaches out to the frame in the region where the floor slopes
up under your feet. It's a rather crude setup, and mounts the motor so
half is under the hood and half in the old transmission hump.

Tim and I have our doubts, but it's Michael's project and that's how he
wanted to do it. This is his first EV conversion, and he's getting lots
of contradictory advice from many people who likewise have never done an
EV conversion before. Ah well... it's a good learning experience.

On the battery boxes: He made cardboard battery mockups, and kept
juggling and packing until he found a workable arrangement. He then made
Styrofoam battery boxes, and test-fit them. Then he fiberglassed them
inside and out with West System epoxy and glass cloth. They sit on
pieces of aluminum angle, bolted to the 'Vette's frame.

> I appreciate that there are reasons why it was a good idea to
> convert the vehicle as was done, but there *were* feasible
> alternatives that could have allowed a tranny to be used for no more
> money, and possible less, and without sacrificing performance.

Sure; there are always other ways to do it. Doing it for the first time,
there is no "prior art" to draw upon. It's a judgement call; you have to
pick what seems best to you, and try it. Time will tell if it's a good
choice or not!
--
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

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Re: Electric motor with no tranny for conversion

EVDL Administrator
On 24 May 2008 at 12:26, Lee Hart wrote:

> But essentially *all* EVs designed from scratch have no transmission.
> The exceptions are the rare ones.

I can think of two more or less recent examples offhand : the Comuta-Van and
the Chrysler TEVan.  The C-van had a 3-speed Borg Warner transmission that
Jim Tervort once told me had originally been designed for a 1930s vintage
Dodge (!).  The Chrysler had a 2-speed gearbox about which I know nothing
more.  Rod Hower had one and was involved in designing the vehicle, so he
might know more details, if you care.

No doubt there are other examples, but my impression is in accord with
Lee's; most factory EVs (not conversions) in recent years have had single
speed drives.  The obviation of the need for a multispeed transmission was
(and is)  considered a significant advantage of electric motors over ICEs.  

David Roden - Akron, Ohio, USA
EVDL Administrator

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