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About WisDesign

  • Birthday August 7

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  • Location
    Santa Cruz, CA
  • Interests
    1968 BMW 1600 Resto-mod in process, motorcycle racing,

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  1. The box ended up being just under 22" wide at 21.75". Cool to see you're making good progress as well! Having all the bodywork done already makes things a bit stressful as we're loading heavy batteries in and out of the car... !
  2. So I thought I was well on my way to completing my 4th battery for my 1968 1600-2 restoversion. Unfortunately, on closer investigation using the foam core mock-up I had built, we realized that the freshly installed rebuilt brake booster and master cylinder created a not-so-insignificant interference. The photos below show the basic idea of the front battery pack sitting under the hood, above the motor and transmission. When we previously checked this position, the brake booster was not installed... doh! After drowning my sorrows for an evening, I started playing "what if
  3. WisDesign


  4. Ooooh... keep me posted on the Vintage Air solution. I've got no plan at the moment for such driver comforts...
  5. First of all, let me say that I am thankful for a forum in which we can have a friendly exchange of ideas. Anybody just thinking about, interested in, or actually building a conversion is more than alright in my book! Not because I doubted anyone, but out of my own curiosity, I ran my own spreadsheet on the Tesla small motor solution and it looks like a very good solution. At 274Vdc nominal, you're around 78% of nominal voltage for a full pack, so base speed on the motor should fall around the same percentage. Agree that you will land around the 200hp mark at the wheels and the bonus is that the gear reduction and differential should be overbuilt for that power level. The 54kWh battery seems adequate to hit that peak power level/current at less than 4C discharge, although I noted that they require some form of cooling if you intend to run them at over 1C continuous (54kW), which would only be the case if you were taking the car to the track. I think the only downside is that it's a bigger tear-up to the chassis to fit the motor/gearbox unit in the rear and you may end up with a unique solution on spring rates based on how the front/rear weight distribution turns out (same can be said with my solution though). IMO - What really matters in end when it comes to performance is rear wheel torque and power-to-weight. The motor torque is pretty inconsequential if you don't understand the intermediate and final drive gearing. In the case of the Tesla small motor, the single, fixed ratio is 9.34:1 with a peak motor torque of 330Nm. This provides 3082 Nm / 2273 lb-ft of rear wheel torque up to the 5100 rpm base speed (my assumption - could be wrong), which will come at about 40mph and then begin to taper off. Compared to my solution of integrating the 4-speed gearbox, the Tesla solution looks like a pretty darn good way to go. However, I'll have a 257Nm motor coupled to a 4-speed and differential that will provide a 14.72:1 ratio in 1st gear = 3782 Nm / 2789 lb-ft of torque, but only up to about 20mph before it begins to taper off. It remains to be seen if the drivetrain turns to shrapnel at that input torque though. Second gear will provide a more manageable 1500 lb-ft of torque, and carry me up to ~90mph, so I'm guessing this is the gear that will see the heaviest duty cycle. Third is for the highway and Fourth is for the Salt Flats... For me, I've had experience in many direct drive and gearbox coupled electrics and I still enjoy the feeling of rowing through the gears and having a bit more control over the vehicle. For example - gear selection also influences the amount of regen you'll receive as you let off the throttle, similar to downshifting a gas engine as it's the mechanical ratio slowing the wheels. It is novel to me that you can apply the latest electric drivetrain technology and still retain the romance of driving a vintage car. My Dad's electric MGBGT has the stock four-speed and a racing clutch and it's pretty fun to drive. I wouldn't race a Tesla with it, but that's not really the point of the car for him or myself. To each their own, but I thought I'd provide a bit of my own justification. I'm anxious to see these builds completed as they represent different approaches, but are both seemingly being pursued with a lot of passion and consideration into making a high quality conversion. On that note... better get back to it!
  6. I think there is more than one "right" answer depending on what you're trying to achieve. If you've got a plan to do it better... I say go for it. I'd love to follow your build as it sounds like you've got a ton of experience with these cars and I'd learn a thing or two! My hesitance to go all in on the Tesla route is based on the fact that the performance of that drivetrain is based on having a very large capacity (70-100kWh), 400Vdc battery to provide it with power. It seems that many in the conversion world like to quote the specs of the Tesla motor in terms of what it is capable of in a Tesla and avoid the fact that they have far less battery voltage and capacity supplying it, which will certainly limit its performance. I can understand the sex appeal of the Tesla system and I imagine most customers don't really care what the peak power is. I just wanted to try something different by engineering a custom solution for the car. I reserve the right to be completely wrong on all of my opinions...
  7. Brian here. Working on a 400Vdc conversion of a 1968 1600 as Geoff mentioned. Yes - I'm retaining the 4-speed. At present, I've got a 3.91 ratio open diff, but have been keeping an eye out for a LSD. Check out my blog. I am building this up as a "kit" so that others could do the same in the future. I'm also keeping track of my costs along the way. It's not cheap by any stretch, but I doubt anyone here got into vintage cars as a way to save money. Let me know if you've got any questions...
  8. Thanks for the compliment! Back at ya! I think I already follow you on Instagram, but I'll double check. That's an awesome amount of battery capacity for such a small car, well done. What is the total voltage? I'm happy with the EMUS system so far, but won't know for sure until I do the full integration. The ability to reconfigure the output pins in their software is pretty handy and its clear that this is not their first "go" at a BMS. I believe they've been around since 2009 or so. The CCGM (cell can group monitor) can monitor a 16S string, which works perfectly for the LG modules I'
  9. While the battery shown below looks identical to the other I posted, it is, in fact, a newly built battery. As a reminder, I need 4 of these in the car to get to my full pack and roughly 32kWh of capacity, which should be good for over 100 miles of real-world driving range. They will be configured with 2 in series and 2 in parallel to reach the desired voltage and capacity. Lithium-ion batteries are amazing in a lot of ways, but require careful management to ensure the best performance, safety, and longevity. To that end, it's critical to have a battery management system (BMS), which measu
  10. Oh yeah... my trick to getting the glass clean was to use a razor blade to scrape decades of hard water and whatever else stains off of it!
  11. Ah ha! Our little ev conversion club is growing! Pretty cool that we're each taking a different approach to the powertrain components. I've shied away from the Tesla stuff, but I totally get the attraction and the parts are becoming more and more available with their success. I'm using a BMS from EMUS with Cell Can Group Monitors for each of the battery sub-modules. The BMS has configurable outputs that should allow me to drive the instruments. They also have a discrete display unit. I'm not really interested in a giant touch screen in the cockpit...
  12. Thanks for the feedback and tips, Geoff! Definitely helpful and I'm sure I'll be coming back to you with questions once I'm actually trying to get everything working. Very helpful to know someone out there that's already tackled some of these challenges!
  13. A small, but significant milestone was made in the refreshing of the instrument cluster for my 1968 1600 restoversion (electric conversion). Here's what we started with... older model cluster with all black gauges and cloudy glass... the plastic surround and bezel rings were in pretty good shape though. I've always been a fan of the earlier model "silver dollar" gauges and even the late model "cross-hairs" gauges, so these were my least favorite option. I did some hunting on eBay and found a silver dollar cluster that had the plastics poorly re-painted, but the gau
  14. Yeah... I assume that most are surprised by the weight based on how light lithium-ion 12Vdc starter batteries and the like are compared to their lead-acid counterpart. However, in most of those applications, the battery is just providing a burst of power. In this case, we also need it to provide a lot of energy capacity to keep you moving down the road as long as possible.
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