Sunday, July 27, 2008

Bleeding the brakes

I finished bleeding the brakes today and wanted to share a few new things I learned this time around. I've always done brakes in the past as a two man job. One guy pushing in on the pedal while the other guy is releasing the pressure at the caliper. The wife was with the baby and my neightbor was on vacation so I decided to purchase a brake bleeding kit. These start at around $25 and go up depending on quality and are well worth it.
First always make sure the reservoir is topped off before bleeding each wheel. You'll also want to check in the service manual for the order the wheels should be bled in. Yes there is a correct order. Before you bleed each wheel remove the bleed valve completely and wrap the threads with teflon tape. This will ensure that no extra air can enter the bleeding tool air lines making it hard to tell when the process is complete. Replace the valve and attach the bleeding kit to the end of valve. Pump the handle and build up the vacuum in the fluid catcher. If the vacuum doesn't want to build up or won't hold check your connections, find the leak and fix it before continuing. Once you have built up 15-20 in/hg you can crack open the bleeder valve and watch the system bleed itself. At first you should only hear the air moving through the system. You might at first see some dark/old fluid after which the air will come. Finally you should start to see the cleaner/new fluid coming into the tube. It doesn't take long and the bubbles will stop coming up the tub. Each wheel should only take 10 seconds or so. If it's taking longer you may still have a leak at the threads and need to redo the teflon tape or you haven't opened the valve very far making it take longer for the fluid to transfer. When the bubbles stop close the valve. Refill the resorvoir and repeat for the other wheels. Do these steps and you'll have your full system bleed in no time at all.

Saturday, July 26, 2008

A small delay

Last weekend I started creating a new wiring harness. The original wiring harness had so many extra sensors that I didn't need and didn't want cluttering things up so I decided to take it apart and remove all the connections I wouldn't be using in the conversion. Look at all those wires!
I haven't finished the harness yet but will add some pictures of the final product.

I wanted to make sure that some of the existing sensors that I planned to reuse would still register properly. The of which would be the VSS or vehicle speed sensor. I decided to create circuit that would simulate the sensor output using a Basic Stamp microprocessor. These are very handy little guys for doing various tasks quickly using a simple basic language.

Here you can see the simulated sensor working. We are doing 40 Mph in my garage! Ugh, is that the odometer going up? Just as if you were really doing 40 Mph everything still functions and responds normally including the odometer. Don't leave that circuit running for too long :)

Ah yes and last but certainly not least is that small delay that I mentioned before. He was born July 22nd. Mom and baby are doing great!

In the next couple weeks I will be continuing the electronics conversion. The next major step is properly recreating the engine speed pulse. This signal is needed for the RPM gauge, electronic power steering, and cruise controls circuits to function properly. I've ordered a small handheld oscilloscope to make the remainder of any signalling circuits I need to build easier so this step is on hold until that comes in.

Sunday, July 13, 2008

I can't weight!

I decided to weigh everything I had and figure out how much weight I've actually removed so far from this car. There are some weight reduction options remaining, but everything else would cost money so I won't consider them at this point.

Removed items (lbs)
Catalytic converter: 13
Headers/Manifold: 20.5
Mufflers: 52.5
Radiator: 13
Gas tank: 25.5 + 79.2 (full tank 1.3 gallons * 6lbs / gallon)
Misc (hoses, brackets, emissions): 65.5

I've also removed, at least for now the spare time, jack, and tools. These will go back in later but for the initial tests I wanted stripped down: 30

The engine and components still attached is somewhat unknown. The specs say 325 but I'm pretty that is without the intake, starter, etc. I'm going to say 350.

That makes for a grand total of just under 650 lbs removed. Not bad but you always want more on a project like this :) The car originally weighed 2800 minus the 650 puts as at 2150.

Speaking of waiting I found out the motor is going to take longer to come in than I originally expected (up to 6 weeks). I'm going to start working on a few side projects that need to be done at some point anyway to pass the time.

Dismantling Part 2

I finally got some more time and cooler conditions to continue with the dismantling phase of the project. I went head to toe on the car and found every bracket, heat shield, and emissions components that were no longer needed. Then I started in on the big job which was the gas tank. My neighbor had mentioned that it should be plastic these days and not weigh much. I checked on my truck and sure enough it was plastic but after removing the EVAP canister I was able to bang on the tank and it was's gotta go!
The entire rear sub frame must be removed for this job...ugh. Here you can see the car with the rear sub frame removed. You can barely see the black of the tank hanging just below the red frame.

Here is a shot of the rear sub frame. This includes the differential, suspension, etc. I tried lifting it...damn too bad I can't remove some weight from that thing.

My neighbor George who helped with the first dismantling steps came over and found my camera. Here is an "action" shot of the tank bolts being removed. Please notice the all-purpose 5 gallon bucket from Home-Depot. Today its purpose was to make up the difference between my floor jack and the gas tank which was pretty high off the ground.
At last the final dead weight item as been removed! The rear sub frame is back together. I still need to bleed the brakes but don't have time today.

Monday, July 7, 2008


I started the processes of removing all of the unnecessary components this weekend. It was hard to start removing that first bolt but as the hours went on I quit focusing dismantling a 30k sports car and focused on the bigger picture, a clean, low maintenance, and low cost sports car!

Here is a shot just after removing some of the intake system, alternator AC compressor, and cooling system.
Don't forget to label those bolts and keep things organized. It takes awhile but can really save some time later!

Here is one of the tubs I bought to just throw parts into so they aren't laying all over the place.

After two days we had everything major out except the engine. It is amazing how much time is spent disconnecting wire harnesses and brackets that you don't have good access to! Here is a picture of the exhaust system.
Here is the transmission. Although it was removed it will be reused in the conversion. We still need to create the adapter plate from the new electric motor and transmission. In addition a coupler between the motor shaft and flywheel must be created.
Day3 After some more removing of sensors and hoses and other crap it was finally time to hook the engine up to the hoist! This was not easy compared to many other vehicles the front sub frame needed to be dropped 3 inches to make room to get the bell housing bolts out.

It's almost out, just a little further!!!

Success! Look at all that room in there. The new electric motor is only 9.1" diameter and 15" long leaving a lot of room for batteries up front.
There are a few little pieces here and there to remove but the biggest is the gas tank which remains in the car. Just like the engine the rear sub frame needs to be dropped to get it out. Hopefully I can get to that and more next weekend.


I tried to do as much research as possible before jumping in but it's hard not to. Try to read as many books as you can get your hands on and talk to others that have done conversions already. I found the "Convert It" book helpful although it's extremely outdated the basic conversion ideas are still the same. Also the guys over at have some great information that they'll hand out for free just send them an email.

As much I want this to be successful I've planned for the worse. I plan to be able to reinstall the gas engine if by chance the conversion goes south. I bought a couple of plastic storage tubs, lots of Ziploc bags and a label maker. Not only will this be helpful for any parts I can recycle into the build I will be able to reverse the process if needed...lets hope not!

It doesn't take much in regards to tools to get the job done and you can buy a few things as you go if you find you don't have just the right tool. I have a good set of ratchets, wrenches, screw drivers, torque wrenches, etc. Also a floor jack or two and four or more jack stands are a must. You'll also need to rent or borrow an engine hoist. I was originally thinking I could do all this in a one car garage spot, which is possible, but two spots is just right and gives you room to move things around and not trip all over yourself.

Get the service manual for your vehicle! There is nothing worse than wasting time trying to figure out how to remove or reinstall something and it's usually time wasted in trial and error.

Get a friend to help. It's possible to do the conversion yourself but it'll be much easier if you can get some help, especially on removing or installing the heavier items.

The car

At first I looked around at used cars hoping to find some crazy deal on something nice with a blown engine or something. Truth is that it's very rare to find a car in great condition with a blown motor. Usually the driver takes equal care to all parts of the car. Everything I found say within a few thousand was crap, or so old it didn't have the safety features that are great on modern cars (i.e. ABS brakes, Air bags, etc).

The S2000 is a third vehicle for us so I won't be down a car while doing the conversion. In addition this car is only used for commuting to work so it's already a special purpose vehicle and the limited range of an EV fits the role perfect here.

2003 Honda S2000
Curb Weight: 2800 lbs
Battery space: Not much. I think I can squeeze 12(12v 115AH) batteries
I'm shooting for a 144v system. There is just no way this vehicle could go with less than 12v batteries since it can't handle the weight. On the plus side it's light and aerodynamic. I have quite a few plans for reducing weight and increasing range which I'll cover later. I should be able to get 45+ miles per charge and need around 37 to get to work one way where I'll be able to recharge for the return trip home.


I've been wanting to do an EV conversion for awhile but never committed to anything. The ever increasing gas prices and some research pushed me into realizing this isn't that crazy of an idea. I was originally thinking of selling my car and buying something even more economical but the car already got 26mpg commuting to work. So even doubling my mileage just didn't make up for the cost of a new Prius for example vs how much it would cost to convert my current car and how quickly I could recoup that investment.

I currently spend a minimum of $300/month just to get to work assuming I don't drive anywhere else. Cutting that cost in half with a Prius 20-30k would take awhile to pay for itself. The conversion I've estimated at around 6k. Monthly costs being about $30 in electricity. So in theory I can recoup this investment in a of couple years. Not bad compared to the 10+ years for the Prius purchase. Now we know gas prices will continue to raise so it would actually pay for itself in less than that amount of time but not needing gas at all is the real solution and it's just cool!

I haven't changed this post because I wanted to keep the real history of the build. Many are reading this post and not understanding things change. Gas was over $5.00 a gallon when I started and to my surprise it did drop and drastically. I originally was just hoping for 45 mile range and on lead acid batteries. This wasn't feasible so I had to change to lithium cells which blew away my original estimate of only $6k.

Recouping the cost was based on the original estimates and gas prices. I haven't done the math but I'm guessing it will take a very long time to pay for itself if ever. It's now just a project that I've thoroughly enjoyed.