Spec my powerplant: BMW E30 318is

Post by **Scotty T** » Thu, 19 Mar 2015, 21:31

I'm converting my beloved E30 BMW 318is which is in need of major work on the ICE, time for it to go!

I've been looking around, asking around with some vendors and generally trying to work out what I need, and of course I've now become a financial member of AEVA.

The main thing I want is bettering acceleration performance, mainly because I want to show people it can be done easily at a reasonable price, and the car will handle it well. I am keen to get E30 M3 speeds which is mid to low 7 seconds 0-100km, the stock 318is gets 9.1.

I was looking at direct drive and the typical 1K controller and Warp9 DC motor combo but after reading another thread (viewtopic.php?title=help-warp-9-sub-100 ... ive&t=4442) where Netgain recommended not running a direct drive unless racing, or running two motors I have more questions.

Does anyone run two DC motors and two controllers? Can it be (easily) done? Is it effective? With my budget, I thought about 2 x Zeva 600A controllers and two Kostov K9 motors. At about $6000 this is roughly a thousand bucks more than a single Zilla 1K LV and Warp9 (and no water cooling). I really want to do away with the gearbox because with 365000km on it I doubt it would last long.

I know that you can stick a 2k controller on a Warp9 (obviously costly) but I've also heard that is pushing the boundaries of the engine (which would be backed up by what Netgain said about two motors for direct drive).

I don't really want a White Zombie or Ian Hoopers RX7 so I'm looking for a middle ground which seems hard to find information about because most conversions I am finding are not quite what I'd call fast (10+ seconds) or way too fast (sub 5's).

Any help is appreciated.

Post by **Adverse Effects** » Thu, 19 Mar 2015, 21:44

why go DC?

this may help a bit

Damien Maguire Youtube channel

he is doing a BMW E31 840CI EV Conversion

Post by **Scotty T** » Thu, 19 Mar 2015, 22:10

I would like to go AC and do the regen braking but cost seems prohibitive for the same sort of performance.

I guess I would have to keep the transmission with the single AC motors that are available in order to get reasonable performance. The dual AC setups appear really expensive.

Post by **Scotty T** » Fri, 20 Mar 2015, 01:07

The wife levelled my head:

"Stick to your plan, it's your first one, we don't need regenerative braking for long distance and your next project can be making it the fast car" and "I want to tell people we don't even need a gearbox"

Post by **Adverse Effects** » Fri, 20 Mar 2015, 02:12

well there you go you have the bosses permission to make 2 EV's now

Post by **jonescg** » Fri, 20 Mar 2015, 03:04

I would argue that the higher price for going AC is still worth it. Regen in wonderful for saving brake pads. Sounds like your vehicle could use a 100 kW AC inverter, which can be had for $3k-$5k. If you want performance then I would recommend a 150 kW inverter, which sadly tends to be in the $7k-$9k range. Sevcon, Tritium and Rinehart are good options. Of course an industrial VFD will work too, they are just rather big and bulky.

Motors are out there which will take all this power, but they need not be exotic. Either a re-purposed industrial aluminium frame induction motor or an EV specific motor like an Evo, UQM, Ultramotive, Enstroj or Brusa will work. The EV-specific ones are generally more expensive though.

Making an AC drive spin backwards for reverse is a cinch - compared to using break-before-make contactors with a DC setup. Although I think some DC motor controllers do come with a reverse feature.

Post by **Scotty T** » Fri, 20 Mar 2015, 16:57

Hehe yes 2 EV's or a further evolution of the BMW

I can't find any 100Kw AC inverters listed for less than $4k USD. Anything under that is producing less power and torque than the ICE and way less than what can be had from a 1K/Warp9 combo. $9-10k just for the powerplant is well out of my budget. Totally not keen on running a re-purposed motor, I hope to get what I need from local EV suppliers off the shelf.

We don't really use the brakes much here in Canberra so brake pads aren't a big concern

Post by **Richo** » Fri, 20 Mar 2015, 20:55

Although I sold it before completing it you could look what I wrote up on my E30.
viewtopic.php?title=richos-ac-bmw-e30&t=1372
The motor probably still exists somewhere in WA.
But I still don't see any AC controllers that are good value for it anyway.
ebay 150HP Industrial Controllers are still around $7k so not much better value.

I'd probably stay away from using 2 controllers with 2 motors.

I'd probably ask Rob at ev works about his E30 with DD 9" for what it's like to drive and what he would do differently with the stuff he sells now.

Post by **jonescg** » Fri, 20 Mar 2015, 23:20

I know of a 100 kW Rinehart you can have for $3k. 360 V max. PM for details.

Post by **Adverse Effects** » Sat, 21 Mar 2015, 01:14

i always liked the idear of the Australian version of the Cougar open source controller

Post by **a4x4kiwi** » Sat, 21 Mar 2015, 01:31

If you are interested in an ac kit, I still have mine for sale.
See viewtopic.php?title=set-of-azure-dynami ... ale&t=3834

Mal.

Post by **Scotty T** » Sat, 21 Mar 2015, 04:43

I read that whole thread Richo and the other one who did the Baur Cabriolet on DC. Great info. I also looked at Renard's BMW. Some common-ish stuff to E30 so that was also useful.

I contacted EVWorks, and they confirmed that DD is OK with my proposed setup and I would get same or better than I have now. I've also been in contact with Ian from Zeva and he was very helpful too.

I appreciate that jonescg, but I really don't want to do my first build with second hand parts despite that huge saving. What I'm after is warranty and support and a simple build.

Post by **jonescg** » Sat, 21 Mar 2015, 04:46

Fair enough, but Rinehart have been enormously helpful, even if they can't offer a warranty.

Post by **Scotty T** » Wed, 29 May 2019, 17:16

@jonescg I've come full circle on this and want to start looking at getting bits. Kicking myself I missed @a4x4kiwi's kit, wondering who got it and if they finished their build. Then again it would have sat in my garage for years

I really like the idea of re-using purpose built motors and it seems pointless now to go DC.

Current thinking (pun intended):

Siemens motor: http://store.evtv.me/proddetail.php?prod=1PV5135

Controller. Either a Rinehart ($$$, good support). Liquid cooled AZD DMOC as shown on above page. ($$, no support, could pay someone to program). Air cooled AZD, why is it so much cheaper? That seems like heaps for liquid cooling but obviously it would be better, For my application, commuting <40km/day, maybe some longer trips on weekends, not flogging it but some spirited driving, thoughts?

Gearbox. Malcolm reckoned direct drive would give 7 seconds 0-100 with the right traction pack. Rough calculations say that would wind out around 269km/h top speed. A 2:1 reduction gearbox like the one EVTV sells would mean 135km/h top speed but I imagine the acceleration would be nuts. Speed limit it is 110 and no racing on tracks where I'd want faster so I guess it would be a matter of budget. I'm not sure if there's a cheaper option.

That's about as far as I've thought for now.

Post by **jonescg** » Wed, 29 May 2019, 21:33

Great to see you're back on the wagon! AC motors are the best, especially when made to work direct drive. Try and get a motor with enough torque so you can just avoid the gearbox all together. Settle for a sop speed of 140 km/h and you will have oodles of launch.

Post by **Scotty T** » Thu, 30 May 2019, 09:15

ThIs actually looks like a lot better package and 300Nm so probably wouldn't need a gearbox.

http://store.evtv.me/proddetail.php?prod=UQM100

Post by **jonescg** » Thu, 30 May 2019, 09:18

Yep - solid choice.

Post by **Richo** » Thu, 30 May 2019, 12:26

Ahhh what about the bus kits on the other thread.
Has the yoke output for direct drive.
140kW.
The torque seemed to be about the same as 2nd gear.

Post by **Richo** » Thu, 30 May 2019, 12:27

http://forums.aeva.asn.au/viewtopic.php?p=73170#p73170

Post by **Richo** » Thu, 30 May 2019, 12:33

Scotty T wrote: ↑
Thu, 30 May 2019, 09:15
ThIs actually looks like a lot better package and 300Nm so probably wouldn't need a gearbox.

http://store.evtv.me/proddetail.php?prod=UQM100

jonescg wrote: ↑
Thu, 30 May 2019, 09:18
Yep - solid choice.

Ouch AUD$18,000 + Shipping + duties and taxes
Didn't the UWA lotus have one of those?

Post by **jonescg** » Thu, 30 May 2019, 12:50

Well if the exchange rate wasn't so awful, yeah, it's not cheap. But lightweight, compact AC power is never cheap.

Post by **Scotty T** » Thu, 30 May 2019, 19:15

Richo wrote: ↑
Thu, 30 May 2019, 12:33

Scotty T wrote: ↑
Thu, 30 May 2019, 09:15
ThIs actually looks like a lot better package and 300Nm so probably wouldn't need a gearbox.

http://store.evtv.me/proddetail.php?prod=UQM100

jonescg wrote: ↑
Thu, 30 May 2019, 09:18
Yep - solid choice.
Ouch AUD$18,000 + Shipping + duties and taxes
Didn't the UWA lotus have one of those?

How does $6495 USD come to $18000 AUD? On today's USD price and it's $9375. Maybe a grand or two shipping? Maybe no tax because it is second hand? If there's one in Oz up for grabs I'm keen.

Post by **francisco.shi** » Thu, 30 May 2019, 19:37

Would you consider the motors I am using with the inline planetary gear box?
It will give you about 660Nm out of the gear box. You can connect it directly to the rear diff with a cv joint. You can see some pictures of how it fits and how it looks on my conversion thread. (Francisco's electric Pajero)
Also I am about to order some batteries if you are interested in getting some.

Post by **brendon_m** » Thu, 30 May 2019, 19:41

Scotty T wrote: ↑
Thu, 30 May 2019, 19:15
How does $6495 USD come to $18000 AUD? On today's USD price and it's $9375.

If you add all the ancillaries (gear box, water cooling etc) it comes to $13000usd, which is $18000aud. I'm guessing that's where the number came from

Post by **Richo** » Fri, 31 May 2019, 13:08

Well at the least the controller would have to be added.
But I added all the other stuff.

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