Sunday, January 8, 2012

Getting things into motion

In the world of physics, it is universally understood that a large amount of energy is needed to overcome the inertia and the friction an object is experiencing, in order to bring it into motion. After an initial velocity has been reached, less energy is necessary to maintain a constant velocity.

I hope the same holds true for my project. I have recently realized that I have had the S2000 in my possession for six months, and have not accomplished much more than planning and disassembly. After sitting down for a short period, and putting things into perspective, I realized that I have to accelerate my work. Summer is approaching quickly, and I need my car by then.

That said, I have begun to order parts, and design more in my free time. I hope that once I begin receiving parts, my work will go along quicker and I will be more prolific on the project throughout the week. Once I get the gist of the process, I pray the project will be completed in about six months.

/ End rant /

Now, to the interesting part!
Since the last update, I have completed a couple of small things.
After discovering the immense amount of space the soft top occupies, I went directly to removing it.

Originally, I had anticipated purchasing a hard top for the car, but after driving it while it had a gas engine in it, with the top down, I found my decision to use a hardtop or soft top fluctuating.
Replacing the soft top is expensive, but a hardtop is even more expensive.

After removing the soft top (which is extremely heavy), and finding an immense space available for batteries, I made a final choice to purchase a hardtop.

Since an OEM hardtop would have a cost rivaling that of the entire car, I will most likely go with a cheaper, more aerodynamic approach. A knock-off Spoon 2 piece hard top from VIS will most likely be the winner in this hardtop showdown. Not only will it make the car appear more stealthy ( :D ), but it will also increase aerodynamics, while still allowing for the space previously occupied by the soft top to be used for battery placement.

VIS Spoon Replica Top

What I hope the car will look like with the top installed

After much deliberation, and studying, I have decided to shy away from using an under/overdrive. Cost, extra work, and extra complications involved while using a transmission have been the primary deciders for me.

Instead, I will use a direct drive approach, coupling the motors directly to the rear differential. With this decision, it will be necessary for the weak stock s2000 differential to be replaced with a 8.8" Ford pumpkin.
A day or two after posting on craigslist proved successful, and I picked up a 8.8" with 3.73 gears for $75 from a man half an hour away from my home. Work has already begun on adapting the large chunk to fit into the s2000.

The 8.8 with cover removed

Some calculations showing RPM vs. MPH

A major effort to design a suitable motor mounting plate has been made over the last two weeks. I have done an innumerable amount of research on the topic, until I stumbled upon the John Wayland's dual 8" warfield design from late 2000.

John employed a simple U-channel design, constructed out of a single piece of aluminum to hold his motors in place. 

I seized the opportunity, and designed a common plate for my dual 9" motors, taking ideas from John, and introducing some of my own. 

While I have not completed the final rough draft, I have already a metal worker assisting me, and should have the basic U channel out of the shop by next Wednesday. 

John's common plate

Another view

Another view, without motors

My first draft of a common plate

I also purchased a single Kilovac Bubba contactor, its a lot bigger than it looks!

 More updates soon!