Front Suspension Fit, Video Update #2

Video Update:

For those of you who prefer to read I’ll be covering:

  1. The challenge of trying to save money on parts
  2. Distractions from the project
  3. Front suspension fit considerations

1) Parts:

I’m still working on the initial phase of getting the Model S running without error codes before moving parts to the Vanagon.

It feels a bit slow, but progress is being made. I’m expecting a used steering rack from a wrecked Land Rover Evoque to arrive soon. DHL got it earlier this week in the UK and it’s headed to Oregon. If it all works out then the $700 plus time invested will pay off. I’m hopeful that the Land Rover aluminum housing will work with the Tesla electronics parts, if not then that was just a learning experience and I may need to buy a new one after all. 

I’m hoping to find a set of stock 19″ wheels with Michelin tires for a good price. I hear the Michelins have lower rolling resistance and I’m going to need every little bit to get near my target of 200 mile range. Lowell Simmons has helped a lot trying to get a set that I found online in his part of the country, but as of today the seller seems to have disappeared. Buying new parts may cost quite a bit more, but at least the suppliers are reliable. The adventure continues.

Do you have a friend at a Tesla approved body shop? I’m looking for damaged parts that they may be throwing away. I expect to modify these parts on the final conversion and so it seems a waste to buy them new when all I need is to make the electronic systems happy. Parts I no longer need are marked with an *. These are the parts that I think may be helpful:

  • Active louvers, all three. Wiring harness parts for them as well
  • * Left AC condenser and fan. It just needs to hold refrigerant pressure
  • * Left hose, pressure sensor and fan controller for above
  • Coolant radiator
  • Left headlight
  • Left side marker light would be cool too, but not that important

I’m also looking for these parts in good working condition. If you know of anyone parting out a Model S please let me know. I’ve posted pictures of some of these below. (edit: I’ve ordered all these parts new from Tesla)

  • * Left Steering knuckle
  • * Front Air Strut
  • * Lower control arms
  • * Brake line, Height sensor, Wheel speed sensor

If you have any leads on any of these parts, please let me know with a message here.

2) Other Distractions

As much as I’d like to spend all my time on this project, I’ve been working on some other good projects as well.

I designed the Zilla motor controller years ago and I’ve been working on experimental code allowing it to use a wide range of accelerator pedal inputs.

I’ve also been assisting Hai-Yue Han as he works on the Tri Zilla project. It’s all back-burner stuff since we don’t know if it has a business case, but the Tri Zilla has the potential to be a 1000 HP AC drive which is plenty of fun in itself. Initially we plan to run it in the Honda Insight with a GM EV-1 motor as a proof of concept, but someday we may put it in the Stretchla for higher power testing.

3) Front Suspension Layout

Several times I started on this update, and each time I’d feel I’d done so little on the project that soon I’d be measuring the front suspension since that’s as one of the difficult parts.

I intend to use the Tesla suspension and brakes for a number of reasons. I love the adjustable ride height and smooth ride of air suspension, especially on washboard dirt roads. The rated axle weight capacity is 808 lbs (367kg) higher on the Model S. The ventilated brakes and Brembo four piston calipers are huge, and the ABS system is required in order to safely allow regenerative braking.

The front suspension is a challenge since I am trying to optimize ground clearance and reduce aerodynamic drag all while avoiding raising the front seats.  The front seats happen to be located directly over the front suspension on a Vanagon. I’ve been measuring every which way, and when I didn’t like the outcome I’d measure more and more accurately but it’s still a tight fit.

The Tesla front suspension looks like it was designed for excellent handling, light weight and a great ride but it was never intended to fit under the front seats in a VW van. The Tesla seats feel wonderful, but are also about 10mm taller from the mounting rails to the seating position than the VW seats. These things add up.

There are a couple of critical interference points in this mashup. The Tesla tires are almost 4″ larger diameter than the Vanagon tires and that puts an absolute limit on how low the VW body can sit since the top of the larger tire will rub inside the wheel well. The wheel well can’t be raised since it has a seat above it. But the more restrictive limit is that the height of the Tesla Suspension from the bottom of the lower control arm at the pivot (I’m assuming that I’ll make a new subframe) to the lowest clear area for the seat rail. This distance is about 665 mm. Ideally I wish it were closer to 610 mm and the extra 55 mm will have to extend under the car. This will reduce ground clearance while increasing aerodynamic drag. The alternative would mean making suspension pieces to some custom design which seems like a huge project in itself.

In this case I think I’ll accept the compromises and make it fit as best I can. I expect it will increase the frontal area of the van and therefore the air drag by about 5%. I can live with that even if it means I’ll have to perform some minor aerodynamic miracle to reach my range targets. I have friends from the OSU Solar Car Team with Aerodynamic modelling software and it looks like that optimization is going to be more important than ever. We’ll have to see what we can do to improve the efficiency. But most of that can wait until the Stretchla is up and running. I love the fact that the Model S displays energy use in Watt hours per mile, that will make it easy to quickly evaluate the effect of any modifications.

Thanks for following along, knowing that you enjoy hearing about it makes this blog worthwhile. Thanks to Nikki at Transport Evolved, it was fun to be on your show and I love your idea that we could all be wearing “i void warranties” shirts. Extra thanks to those of you who have contributed time and funds to help obtain the needed parts!

10 thoughts on “Front Suspension Fit, Video Update #2

  1. I’ve been reading your previous blog posts and thought it’s time I let you know how much I’m enjoying following your journey, one that many of us can’t do ourselves, but we live it through you!- Andrew from Tasmania in Australia.

  2. Thanks Andrew,
    I appreciate hearing that you enjoy it. Site hits indicate something, but it’s comments like yours that keep me writing about it.

  3. Otmar,
    Great video update! You are looking very comfortable in front of the camera. Good luck with the parts search.
    Karl

  4. Cracking story this…the sheer determination to leap into the dark with a project like this and to ‘make things fit’ while weighing up a whole host of pros and cons with countless avenues of transfer is a joy to see. It’s going to be fascinating to see just how many of the great Tesla characteristics you manage to meld into the stretched Vanagon. You are a legend, fella! Greetings from Finland.

    • Thanks Mark,
      I think my title and therefore page link was too long. I’ve shortened it and it seems to work for me now. I hope it works for you too.

  5. Another well done and informative video Otmar! You are a natural in front of the camera. Keep the faith, I anxiously await the day you bring my old baby back to life! All the best, Joe

  6. From the Tesla blog re: collision repair shops.

    http://www.teslamotors.com/fr_CA/forum/forums/collision-repairs-insurance-companies-body-shops-and-tesla

    DouglasR | 4 JANVIER 2013
    Tesla has approved an aluminum-certified body shop in the Seattle area. It is Queen City Auto Rebuild in Redmond, WA. It’s got a very good reputation, but I was told by an insurance guy that it’s the most expensive body shop in the state — handles very high end aluminum body cars.
    I assume that they would get their replacement parts from the factory and do the body work themselves
    JonathanDurning… | 6 AOÛT 2013
    Drive cautiously everyone. Our recent minor dent/scratches on rear passenger door and quarter panel were just estimated at Beaverton Oregon Precision Auto body for 5,591.20. Ouch. I suspect Insurance rates will likely be going up.

  7. Love the old school phone prop. I can relate to the amount of “head scratching” required when trying to convert a modern vehicle. Making all the sensors happy can be a challenge. You’ll get there, I’m sure.

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