Search found 16 matches

by designerguy
Mar 03 2018 2:27pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

What is the thinking behind so many motors and twice as many controllers? Is there any advantage in it? 6 motors and 12 controllers are a lot of opportunities and space for things to go wrong and cause unwelcome costs. Plus, they'll take up the space you may want for more batteries, more power. The...
by designerguy
Feb 25 2018 1:01pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

I would keep a eye on the active suspension side as a potential option long term. Agree, that it would be much more complex and have tons of downside on the reliability side, but the potential upside could be ground breaking. Not just active, but pre-active. Gas sprung inline motor - generator actu...
by designerguy
Feb 25 2018 7:58am
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

I would like to avoid active systems as much as possible. Most tend to come with a hefty weight penalty and have a greater number of failure modes. However, I am intrigued by your system. Is it similar to an SM? I plan on make the body plug the old school way: using Masonite sections every 4” or so ...
by designerguy
Feb 24 2018 8:37pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

I’m trying to be really open minded to what an electric car CAN be. Many of the trade offs that IC cars make simply don’t need to exist for an electric car. An update on the goals for the project; the Midwest and especially Michigan are having a record year for pothole damage. After driving my wife’...
by designerguy
Feb 23 2018 5:18pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

A couple point for clarification: -not in wheel motors but rather one motor for each wheel with a driveshaft...the trade off in ride and handling aren’t worth the ease of packaging -I’m not necessarily going to reduce the rear track vs front track, however, narrowing the rear track won’t make the ca...
by designerguy
Feb 18 2018 4:19pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

I played with narrowing the tracks, rear track more so than front. Drag area is now 0.22 m^2. That's a decrease of 21% from the previous test. I want to play with how much I can reduce drag for maximum range.
by designerguy
Feb 15 2018 6:23am
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

If the lams are staked together at a location that has little to no flux density change as the motor operates, it will cause little to no added eddy/core loss to have them electrically connected. You may find soon enough that putting less mass and bulk in the reduction stage and more mass and bulk ...
by designerguy
Feb 14 2018 8:30pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

GOOD NEWS! Stator losses are only about 50W per motor at 30m/s! (At least per the simulation) I suspect it will be a bit higher since the laminations are joined together via a stamped tab, shorting the stack. There will also be stator, bearing, windage, drivetrain, and controller losses to take into...
by designerguy
Feb 14 2018 5:31pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

For the controller I’m looking at 3 MTI85W100GC similar to what you had posted in one of the threads. It would be nice to be able to buy MTI145WX100GD so I could actually make decent power though.
by designerguy
Feb 14 2018 10:50am
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

I’ll be needing to make 8 controllers :lol: I’m hoping to develop a nice compact 25kW powerstage for the SMD controller for insane ebike and light motorcycle use. Once again I’m learning as I go with all of this :lol: To put the drag into perspective the first gen insight has a CdA of 0.56m^2This ha...
by designerguy
Feb 13 2018 9:06pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

The Stratos is pretty lovely..... Here is the latest iteration. The Cd now stands at 0.181. It would be great if these numbers were accurate! 4.5 KW aero-load at 30m/s! Now that the aero package is coming together I need to start on the motors to make sure I don't lose too much in iron losses at spe...
by designerguy
Feb 11 2018 7:12pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

i have the CFD software working a little better now. I have been running non-stop simulations, iterating to get a lower Cd. So far I'm at 0.20 for the Cd and 1.54 m^2 frontal area. That gives a drag area of 0.307 m^2; ~the same drag area as a bicyclist with drops! That's about 7kw at 30m/s (highway ...
by designerguy
Feb 07 2018 8:24pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

I'm currently working on getting some more accurate CFD software to test ideas before I show the whole design. I thought I would leave this teaser here for you, though.
by designerguy
Feb 01 2018 8:28pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

Got the batteries and stators in tonight. Made a quick model of the center battery box/ frame and ran a torsional moment through it. It gets about 10k lb-ft/deg just with just the center frame and no passenger cell!
by designerguy
Jan 28 2018 12:57pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Re: Lightweight AWD Sportscar

Registration is pretty easy in Michigan. If I follow basic FMVSS guidelines I should have no problem. Insurance will be another story but I cross that bridge when I get to it. I do plan on using regen braking with the belt drive. LTO have an insane charge rate (8C) which translates to 152KW under br...
by designerguy
Jan 28 2018 12:33pm
Forum: Large EV General Discussion
Topic: Lightweight AWD Sportscar
Replies: 35
Views: 2998

Lightweight AWD Sportscar

I’ve just started on the design and development of my own personal project car. I have been a long time reader of these forums, constantly inspired by all the collaborative development that happens. Some background: By trade I am an automotive exterior designer. I work at a one of the big 3. Last ye...