I've driven my Tesla Roadster 32,000 miles all over Europe in the past couple of years and have enjoyed every single mile
I'm ready for my next EV and intend it to outperform the Roadster. I would be interested in members views on achieving the following in a 2 seat sports car;
0-60 <3 seconds
150mph
range 150 miles (everyday pack), 300 miles (extended range pack)
It's certainly doable but your requirements make for a difficult DIY. You can get all the power you want from Warp 9s or 11s, I've heard of up to 4 used in series...but you want regen, so you're stuck with whatever AC motors are out there. Maybe you could get 3 or 4 of HPEVs new stuff...
The other issue is range. It's difficult to get over 100 miles with DIY EV batteries in a small car. Tesla had to use thousands of laptop cells, which you can cram anywhere.
Contact EIG and buy a ton of their batteries. Easier to package than thousands of the panasonic cells. Then buy a EVO Electric AFM230. Mate that to a Sevcon Gen4 Size10.
Make a 800V 40-50kWh pack that can do 400kW with a motor and controller that can do close to 300kW. This will probably cost close to $25-30k for the controller/motor and then $40-50k for the battery. Then maybe $20-30k more for materials and fab work. Charger would be another $3-10k
Put all that in some sweet ass sports car and you're good to go. I would think you could get about 200 miles out of a pack that big when you aren't riding it hard. Your talking like 800 lbs in batteries and 160lbs in motor/controller. So your car may be quick heavy.
This is probably the route I would go, but with 30kWh or so. That is if I had $100k to spend on something. Actually I would go with 2 hub motors, 30kWh, and try to weight down to 2500lbs or something.
Contact EIG and buy a ton of their batteries. Easier to package than thousands of the panasonic cells. Then buy a EVO Electric AFM230. Mate that to a Sevcon Gen4 Size10.
A dual drive/AWD setup (~40K$) should meet your acceleration and top speed needs. They have regen and also great efficiency so that should help towards your 150mile goal, which is primarily dependent on your batteries.
For batteries your best bet is the A123 20AH pouch cells. 500g each.
200series 3parallel = 600 cells = 660lb pack. 30$ each to your door = 18,000$ total (not including cost to test, build, and protect the pack)
660V nom. * 60AH = ~40kwh, which is 150 mile range if you drive it to 100% empty and average 267wh/mile while doing it.
So total with the three most expensive components is $58,000 USD
Only thing left to do is choose a donor you like....
Note: Keep in mind if you were willing to forgo Regen and use a DC system with a shift or two you could obtain the same acceleration goals for ~38K$ or 20K$ cheaper.
I left that out on purpose because I wanted to encourage people to blue sky this a little... I'm happy to spend money on things I care about and expected this spec to require something in the $100-$200K range.
Note: Keep in mind if you were willing to forgo Regen and use a DC system with a shift or two you could obtain the same acceleration goals for ~38K$ or 20K$ cheaper.
I undertake a lot of promo work for ZCW and other charities and the new car will be part of that activity. I also want to compete in more mainstream car events like Gumball 3000 and some of the trans-europe rally's. Today this is difficult with the current Roadster's range and charging rates.
I'm talking to several EV drag race and record attempt teams... very happy to talk more if you'd like to PM a number.
It's very unlikely that I will get the time to build this car from scratch. However, I have a computer hardware/software background and expect to do as much work as time allows.
I would talk to Bob Simpson at evdrive. I met him a few weeks ago and he is very smart and energetic, and his drivetrain is very scalable and impressive if you have a little money to play with.
Since you are wide open to things. Mission Motors probably makes one of the more power dense controllers on the market http://ridemission.com/. Their motors are ok, but not as good as others I have mentioned. Their battery packs are made with EIG cells and I think they are looking to use the newer 40Ah packs if premade packs is more your style. The panasonic are still the most energy dense cells in both volume and weight, but they lack some power capabilities.
On another note I am dreaming about putting 4 of these on a car someday. http://www.proteanelectric.com/. That is your motors and controllers all in wheel. Leaves the rest of your room for batteries, charger, electronics and cooling. Over 4000Nm peak at the wheel capable. That is awesome!
Mate Rimac, username Crodriver on here, will sell you similar drivetrain components to what he is using in that car. It isn't cheap stuff, but it is very good. IIRC, he was able to get the BMW to run 11's with just one of those motors.
I would like to add that it is actually easier to obtain regen with a DC set up than with an AC setup, if the DC motor used is a sep EX. The people on here telling you that DC regen is not possible are assuming series wound DC motors. The only issues with a sep EX motor is you must know its field map and I do not know of any DC EV controller on the market in high power for such motors. In industrial manufacturing these controllers are common though, but require AC input because of using thyristors that are dependent on the AC sinewave to shut them off at the zero crossing.
As previously suggested, I'd look into sourcing a motor/inverter from CroDriver (Rimac). He's put some of his stuff in an Opel Speedster already (http://www.facebook.com/photo.php?f...202.100003295904581.1189320210&type=1&theater), which is, of course, a close cousin of the Tesla Roadster.
Perhaps he might privately divulge what kind of performance he is getting with it.
Other thoughts: If Mission Motors will sell you two or more motors (AWD might be necessary to achieve that kind of acceleration without the benefit of slicks), using components like that might be more effective than trying to liquid cool a Tesla Roadster motor.
Also, you might consider an Ariel Atom or KTM X-Bow chassis (or similar) to trade off need for horsepower with weight reduction.
Similarly, you could even duplicate, or try to improve on, the Toyota Motorsport GMBH P001 that just won the electric class in the Pikes Peak International Hill Climb. (http://green.autoblog.com/2012/06/08/toyota-plans-radical-raid-on-pikes-peak-w-video/)
Hi Kevin,
Just in case you haven't come across them before, I'd suggest looking at Yasa motors – they're built in Oxfordshire: http://www.yasamotors.com/technology
Love the idea of a high end conversion . As I have said before 4 motor 4 wheel drive , ac, . but a 5th motor needs to be added with a powerfull fan that sucks air from under car and blows it forward for breaking /down force . Other directions for stability control . In full hard 4 motor regin huge amounts of power are generated ,the fan motor could use this if capable . Gas cooling (He or H ) would keep the heat more manageable . This is comon in utilty generators . My spell check needs to be downloaded !
Switched reluctance motor seam to hold a advantage over sine wave ac in that they run on square wave( 10X less switching ), less heat in the rotor and full torque at start up. I would gas cool the controllers also. SR motors are more common in the EU.
Finally getting back to this project... we've been busy donating Charging Stations and now have more than 440 installed around the UK and a major international hotel chain about to announce a programme to install at all their locations
I've also been working with two of the Formula E teams and in my 'spare' time reading lots more about EV technology, watching EVTV, developing OVMS and OCM, etc.
I'm probably going to use the experience of building my next-gen Roadster to help train up a group of young people and start a conversion company in the UK. I like Jack Rickard's approach to open EV components and will try to support that in the builds that we undertake. If anyone is interested in collaborating on any of this then please PM me.
With regards to the Roadster Project, anyone have any updated advice on component selection for our build?
I have a proposition: It seems ever more unlikely Tesla Motors will spend their R&D on upgrading an old and discontinued product. Why don't you exercise your muscle and try to spec and produce 'an upgrade kit':
- new battery with modern top-of-the line cells - (maybe even 3 versions - same kWh at lower weight, some more kWh at a bit less weight, even more more kWh at same weight as now)
- beefed up PEM and motor cooling - higher sustained performance?
- some tweaks into brakes maybe
- you could look into AWD upgrade for the roadster. Front motor(s?) needn't be very strong, they would aid acceleration and strengthen regen through cornes.
I'm sure you'd get ton of exposure and even some business opportunity.
Well they "crammed" them into one giant block, which you can do with any cells. The reason they went with those cells was because of cost and energy density.
+1 for AWD upgrade. It would be easiest to do as you could retain the old drive system as is and still get a lot more power. And this power would be very usable as the traction would get better. It would also make the regen even better.
AWD just adds weight , cost , and efficiency losses.
Its not necessary for street performance ( eg Ferrari, Aston, Porche & Tesla have shown that). So unless you plan a World Rally attack, why bother.
Focus on refinement and range after performance is satisfied.
Not true.
AWD enables better dynamic control i.e. torque vectoring. It enables strong acceleration and stronger regen not only in straight line but also through curves etc.
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