Repost of first long MIMA drive 24 July
Well Insight 00 #4738 has MIMA-C Ser #001 installed. I drove up to CT and Mike guided me through the install. It was a lot of fun looking around in the battery compartment. We spent about a day and a half but a lot of the time was spent looking at a lot of Mikes other projects. He has a few more installs lined up and the others will probably be faster unless they do what I did (Mike whats that?). I think there are about 40 wire taps needed and by the end I was felling pretty confident in the sodering of the connections. Mike built my circuit board (actually he tested it for a week or so in his car) but with detailed instructions I think a novice could handle the install. The key would be to go slow and double check everything. (I had a few mistakes in the process like putting the diodes backwards, cutting the wrong wire etc) but Mike caught them as we checked the wiring). I think when the instructions are complete it will be step by step and thus if you go slow and are careful you will be able to do it. Mike is also planning to have several installation levels that will allow you to tackle the project in smaller chunks to build your confidence as well.
First Impressions:
1. Wow! Being able to tap the IMA for full assist or regen is pretty impressive. Reminds me of the time I drove Willie's little Red Rocket and felt the turbo kick in. It definitely adds to the fun to drive factor. I used full regen on several hills instead of the brakes and it does a pretty good stopping job. The assist or regen response is imediate with no delay or lag. This mode of operation is called the Auto-activate Mode. It allows temporary manual joystick control of Assist/Regeneration. This mode is activated by moving the joystick. After three seconds with no joystick activity (joystick back in the center), the system reverts back to standard Insight IMA mode, with background charging if needed. You can think of it as the manual override to the IMA logic. It allows you to do stuff like get full assist from the electric side even though you are not pressing the gas at all. In other words you are crusing along at 150 mpg in 5th gear and want to pass a car. No need to change the throttle position or downshift. Just hit the joystick and stay at 150 mpg and let the electric side provide the needed extra power. I think this is the mode I will use the most but only time will tell.
2. The next mode is Active MIMA Mode. Its esentially the same as the above allowing joystick control but the car does not return to the Insight IMA mode until you disable the Active MIMA mode using a push button switch. I can see using this mode when you don't want the parasitic background charging. I havn't really spent much time with this mode but intend to get some experience with it in the future.
3. The next mode is called MIMAAUTO Mode. Its kind of like an electric cruise control based upon the MAP signal. Basically if the mpg reading falls below a threshold that you set the IMA kicks in to meet the demad instead of the engine. If the MAP signal goes above the point that you set then the Regen kicks in to charge the battery. Its amazing to see what this can do for fuel economy. Mike and I went out on a test run and got 120+ mpg for over 10 miles but note that we had too high of an assist point so the battery was not staying completely charged. I plan to experiment with various set points but so far have only used the really high ones. This really has a lot of potential when working with a cruise control. I have a Roseta cuise control and when both it and MIMAAUTO are on they complement each other beautifully. For instance when the car slows to the min speed set on the cruise control the cruise control will increase the throttle position causing the vacuum to drop. Normally this would continue until the engine provided enough power to maintain the speed set. However with MIMA-C the dropping vacuum triggers MIMA which reacts much quicker than the engine and causes the IMA to start providing the additional power needed to maintain speed. As the speed increases the cruise control reduces throttle pressure causing the vacuum to increase thus dropping the need for assist. In other words this is a cruise control that combines both the speed and mpg set points!!!!!! (First time I ever tried one of those smile faces.
4. But wait there's more! Mike has a display that shows you the real current values flowing too and from the IMA. I think Honda used a random number generator on the assist and regen guages as they don't show things correctly. Mike uses 4 leds each representing a threshold of amperage. So you can get 1-4 green leds representing 12.5 amps each of assist or 1-4 red leds representing 25 amps of charging each.
5. He is a user of the system and is constantly trying to improve the controls and programing. As a early installation I have no worries about my system becoming obsolete because I can simply email Mike and tell him to send me the chip with the latest program and then my system will have the latest updates.
6. Mike is pursueing a lot of possibilities for our cars and I hope he does well with the sale of this system. Take a look at
http://www.edrivesystems.com/. This is a plug in Prius option for around 10K. With MIMA-C and a home charging option I could see the Insight getting incredible mpg on commutes by using higher set points in the AutoMIMA mode and then get charged later or shift to auto-activate mode to let the engine do more charging. Mike is also looking at a more powerful battery install which would give us all more options when our OEM battery needs replacement and we are well beyond the 80K waranty.
7. Believe it or not I actually was speeding most of the way back to DC. Part of it was having fun with Auto-Activate mode and the other because I lost the fuse to my stereo amp and was getting tired and did not have my usual way of staying alert. Even at 70-75 mph I was getting segments near 100 mpg with MIMAAUTO mode. I would then shift to Auto-activate until I got the battery charged back up. I'll provide more mpg info once I get more testing on a route that I know the result ranges without MIMA.
Notes to Mike:
1. Is there a reason for the 3 sec delay in MIMA autoactivate mode between the no activity on the joystick and return to normal Insight IMA control? I found that sometimes I would use the joystick to slow but then if I tap the brakes I get no regen until the IMA logic takes back over after the 3 sec delay). If this was arbitrary then perhaps cut it to return as soon as the joystick returns to center. Can't see anyone letting go of the joystick and then needing it again in less than 3 seconds but perhaps others will have different feedback.
2. I am still getting used to the interface. I think I hit it sometimes unintentionally. Perhaps I should have used the trigger mount that you use but that is easy enough for me to change later. Anyway I had two times when the car did not start from autostop (I think it was because I bumped the joystick but will test some more). The first time I restarted with the key and the second I just used the joystick and the engine came to life. (I am guessing the 3 seconds also was the root of this but havn't tested the theory). (I assume the manual override of bumping the joystick disables autostart until the Insight IMA logic takes back over).
3. You were right on the new Prius using less modules and lower voltage battery. It uses a transformer to step the voltage up to 500V and the new batteries have a 35% increase in power density which give it the 2 sec faster 0-60 time.
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Rick 00 #4738 Lmpg 90.2 @ 127K miles