Friday, October 30, 2009

Back in Business

The EV is running again!

I took everything apart and decided to replace the only thing that I had a spare part of: the Torque Converter. I figured that the only things I had to loose was 8 hours and $25 of new ATF. The old TC was toast! I guess after 244,130 miles it make sense, so the new TC I put one was the one I got with my sacrificial transmission for constructing my plates last year. It has about 97,000 miles on it so it should be good for quite a while. I have been meaning to get rid of the old engine and transmission for some time now, and I am glad I didn't!

I have also decided to idle the electric motor. I am designing the circuit tonight and tomorrow I will be purchasing the parts to build it. The idle will make it easier for others in the family to drive, and I will be using the old Cruise Control switch to turn the idle On/Off so I can save power while at a long stop light. Though, it only takes about 18 AMPs to properly idle the transmission in Park, and most likely slightly less in gear. Also, having the idle will allow me to use the A/C when the car is parked, when I ever get around to actually building the A/C compressor mount.

Sunday, October 25, 2009


This morning I exercised my vocabulary of 4 letter worlds. My transmission DIED on me a mile from my house. I had just replaced my last battery and took the EV out for a break in run, Not a break Down run!!!

I was driving down the street and went to stop to make a turn, and I heard a very interesting whirring sound as the car slowed down. Stumped, I went to make the turn, heard the whir again, the car lurched forward and then that was it. I glided into the next parking lot and the transmission would not engage anymore.

So now I am ripping EVERYTHING out of the engine compartment and going to take a look at the damage. I am hoping it's just the Torque Converter as I do have a much newer spare. The transmission has 244,130 miles on it and I guess that was it. If replacing the TC doesn't fix my problem, I will be going to the local salvage yard and claiming a new transmission.

I am so mad/sad/disappointed right now it's stupid. I guess by the end of this conversion, I will have rebuilt every aspect of the car that it will be just like new. But for crying out loud, WHY NOW!?!?!?!?! The Zilla is due soon, I just replaced my pack and cleaned everything up.

Thursday, October 22, 2009

Obviously Oblivious

Ok, so I have been having problems with my new brakes, specifically a VERY squishy pedal. I have bled the brakes twice, checked the fluid, readjusted the pades and shoes and still nothing seemed to help. The weather hasn't really been cooperating, so I decided I was going to bring it down to the local Goodyear dealer this morning and let them have at it.

A couple hours later I get a call saying that everything was mechanically sound, it just needed more vacuum!!! I never even thought about the vacuum!!! So I went to pick it up and just cranked up the vacuum and drove it home. Man, what a difference. I just finished cranking the vacuum high enough to provide the extra stopping oomph, but also shut off once it reaches max Hg.

Next on my to do list is replace the last "old" battery in my pack. It passes all the tests Walmart does on it, so I can't replace it under warranty, but I am fine with that because I wanted a good battery to test my BMS modules revisions on, and for camping power. I even have an old car battery to use for core, so I should be all set. I am also still looking out for a new suspension system, the last major piece besides the Zilla. I have found one I like, I just need to see if I have the funds for it.

My Zilla will hopefully arrive the first week of November, according to EV Components. I have been waiting forever for a nice controller, so another two weeks isn't too bad.

Thursday, October 15, 2009

How I Used an Automatic Transmission in an EV

I have been lots of questions on how exactly I used the automatic transmission in my EV. So this insanely long post is a summary of how I did the whole transmission setup.

The first thing I did was design a motor coupling and plates that mimicked the old ICE. I kept the torque converter and flywheel setup, and since it mimics the original engine, the adapter plates and motor coupling can be used with the automatic or a manual transmission. I used the transmission's Flex Plate to design the motor coupler, which is a taper locking coupling. The aluminum plates were created using a second transmission I bought off Craiglist because at the time the car was still driving and I wanted to have as little down time as possible, so I bought the second transmission (which was skipping gears) as a EV sacrifice so I could use it as a template for the coupling and for the bolt hole pattern on the plates.Next, I left the Automatic transmission installed with the existing radiator/transmission cooler. I also left the PCM and ECU installed as they are needed to operate the transmission and the dash board. I also used the old engine mount to hold up the rear side of the 9" ADC FB1-4001A series wound motor. The motor has a rear shaft that will connect to the Power Steering pump and A/C compressor.
After all the mechanical is done, comes "fooling" the PCM. I Do not idle the motor at all. It does take about 6 seconds to build up pressure for the clutches to operate, but that only happens when the EV is first started before a trip. During driving the pressure stays up while at stop lights and such, and getting going again is no slower than with using a manual with a clutch.

Now comes the big question: How did I change the shift points on the transmission? Did I reprogram the PCM? Modify the transmission soleniods? I did nothing of the sort! The key to using to changing the shift points: replace the TPS with a 5 k potentiometer!

In and ICE he TPS tells the transmission when to shift, depending on how hard the pedal is pressed, when accelerating or cruising or coasting. By replacing the TPS with a 5K potentiometer I now can manually tell the PCM when to shift. The higher I set it, the longer it stays in each gear. After 1,000 miles of driving like this, I have had no problems and I have found a few settings that work well depending on which terrain I drive on. Higher RPMS mean better efficiency while lower RPMS allow for better acceleration.

I usually leave it at about 1/4 turn, however it needs to be set to 0 every time I start up the EV because if the TPS (5k pot) is higher than 0, the transmission thinks you are stepping on the gas and will lock the Shifter into place so you cant move it from Park. Annoying, but effective safety measure. And I will not be bypassing that protocol, but if I do the transmission can easily be shifted into Neutral with the EV off, and that is a safety issue that is checked during the yearly Inspection.

Tuesday, October 13, 2009

Battery Mangement System 0.1b

It's been awhile since I have updates anything. I finished my brakes, but I did the bleeding all wrong because I have NO stopping power. I can jammed the brakes to the firewall and the EV will stop, but barely. So I either did the bleeding wrong (which I think I did, pressed the pedal too far) or I killed my Master Cylinder/Brake Booster.

I also have replaced most of my pack under warranty because they were not working right. I have one left to replace, which I plan to do soon. They needed equalizing, but I didn't know until after I replaced most of them. I am going to replace the last one just so it's new like the others.

Anyways, I have really good results with my BMS. Here are pics of a few modules, and then installed in the EV.

I installed these and took them on their maiden drive to school (with funky brakes, but that's another thing) and found bugs in the software. I have a visual error reporting function that is supposed to activate for about 5 minutes, while disable the module, then go back to normal. They would not get to normal, so I sat in the parking lot rewriting the code at 8:30 AM and then updated all the modules.

They have been working really well. During the charging phase, the voltages are pretty much every where because of the batteries each being slightly different in age. (Well, one's about a year older than others.) But once the charger gets to the end, the balancers help spread the final voltages pretty evenly. I was having some problems where some batteries were charging at 15.2 volts and other at 14.0 volts. Now they all charge around 14.6-14.9 volts.