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Ok, this idea came to me last night, and it seems like one of those "might be crazy but could work" kind of ideas. It's mostly based on Mike D's mods to his Insight that's been stewing around in my head for about 3 months.

I think you could do a pure EV mode on the Insight using the factory IMA system. Here's the general idea:

1. Disable injectors using FAS type system
2. Hold throttle all the way open
3. Maintain speed using IMA, controlled by MIMA or other means*

The hope here is that holding the throttle open causes the minimum loss scenario for the ICE, as pumping losses are minimized. It's not quite as good as the intake valves permanently closed as the HCH2 does, but may still be reasonable at lower engine speeds.

*Other means - I've got a crazy idea about replacing the factory throttle cable with a drive-by-wire system from a Fit or other Honda. Or possibly just a stepper motor to pull on the throttle cable. With a system like this, you could have an "EV mode" button like the new Prius2 - it disables injectors, opens the throttle wide, and the actual pedal position is instead used to control the IMA.

With a rechargeable booster pack, it seems like a simple way to add PHEV capabilities to an Insight without the work / expense of the 5th wheel solution.

Feel free to tell me that it won't ever work.

Ben

Spinning the engine would be a huge energy sucker, I'm sure in theory your idea would work... but it would be horribly inefficient. :(

I'm sure with a big enough booster battery pack you could just leave the engine running at idle and use MIMA to power the car for extended periods of time. But talking about mike's 5th wheel setup, I'd think the majority of the cost would be the batteries and DC/DC converters, the 5th wheel is small compared to those two things, which is something you'd have to buy anyway to have a PHEV.

I'm aware there's losses in the ICE, and probably quite a bit, as you're still pumping air from the intake to the exhaust, pumping water, oil, turning belts, etc. Having the throttle all the way open will minimize those losses.

Don't get me wrong, I think the 5th wheel is great, but I really don't see people jumping to tear apart the rear floor of their car to install one. This solution is a pure electrical "hack" - little physical modification or expense.

I know that installing a *complete* factory drive by wire system would involve changing a lot of things, and is probably not possible on the Insight... I was leaning more towards making my own with factory Honda sensors / actuators.

The only reason for pointing out the losses is that to have a battery pack capable of suppling enough current to keep such an inefficient way of doing it would likely cost more than just doing it the 5th wheel way.

I could be completely wrong and I don't want to discourage you from doing it.. I'm sure you'd have a lot of people watching your progress if you did decide to do it :)

Mike essentially already has EV mode with MIMA.

When the Insight is coasting, fuelcut is on and the valves are open.

What Mike and Randall are doing now is trying to find a way to add batteries to the Insight's small pack. It's not as easy as it sounds - if you add or switch batteries, a recal is done just to know what the SoC is - not because the charge is weak.

The big downside of throttle-open would be heat loss, if you're
intending to bring the engine back online at some time later
while driving. There's a mode we call warp stealth in the
Prius, and one of the things done there is to back off the
valve timing and set the throttle opening so that the net airflow
through the engine is very close to zero, but manifold vacuum
is still kept relatively low. I've done a couple of miles in that
fuel-cut state and expected a significant drop in engine temp,
but it stayed pretty well up there. Using the cabin heat pulls
it down faster.
.
If you're starting cold and don't intend to use the engine at
all, then it wouldn't matter..
.
_H*

When the Insight is coasting, fuelcut is on and the valves are open.


Well there you have it. Last time I talked to mike about his V-Boost system he said that they were still in the testing phase and the earliest it would be ready would be spring, IF it worked as well as they hoped.

Mike's work to add batteries will make the Insight a great mixed-mode hybrid....that's half-way between a true PHEV and the stock Insight. Before you get disappointed that it's not going to have great EV capabilities, realize pluging-in extra batteries overnight will give Randall's commutes maybe 125mpg - a gain of 30%. this is because the additional Assist will keep the Insight in the lean burn mode more.

Once I get MIMA installed, I'll be diligently waiting for Mike's V-Boost system to come out... I have a goal of 100 mpg tank averages and that surely will be what puts it over the edge :D

Count me in on this project! Mike D Rocks.. I should have my Mima & FAS installed over the holiday break as long as the temps here are not too frigid.

Please keep me in the loop.

I'm getting about 70mpg with the snow tires and full radiator block in...not bad for my hilly 35 mi commute.

cheers
Wayne

So, testing on commute reveals a minimal gain if any by holding the throttle open with the engine off while coasting in gear at any RPM the Insight is typically found at.

However, from watching the metric mode iFCD, I know that just because your foot is all the way off the throttle doesn't necessarily mean that you are in fuel cut mode - thus, using FAS while attempting an EV mode would be necessary to ensure NO fuel is used, or by engaging the fuel cut relay.

I'm researching the how's of the HCHII's EV / glide mode, maybe we can adapt it to the Insight? I imagine the HCH engine is primarily the same as the Insight, with the addition of another cylinder. Maybe the valvetrain elements could be adapted to the Insight? That would probably be fairly expensive. Maybe mechanically holding the exhaust valves open a bit, but that would make the rocker slap the cam (bad).

The "optimum" would be to install another clutch between the IMA motor and the ICE. That's at the top end of crazy / expensive.

Wow, the HCH2 has a bizzare valvetrain. True 2 valve per cylinder, old school V8 style, ha. the 3 mode VTEC is what does the intake valves shut trick, which will be impossible to duplicate with the Insight valvetrain / head configuration.

I think you could do a pure EV mode on the Insight using the factory IMA system. Here's the general idea:

1. Disable injectors using FAS type system
2. Hold throttle all the way open
3. Maintain speed using IMA, controlled by MIMA or other means

Ben

With the SAFE FAS wired up in the current config, one of the ICE re-start safetys that remain in place is when the accelerator is touched, you get ICE restart. I don't think the hold throttle open thing will work in this case.

With a fuel cut indicator mod it is possible to see the fuel cut, and using MIMA, you can do an EV only sort of thing in the Insight. I find it works pretty well, down around 35mph, in 4th/5th, flat and level terrain, slightly engage MIMA assist and gently let up on the throttle until the fuel cut indicator lites up. Increase MIMA'fied assist to maintain speed.
Limited by the small factory battery.

Randall

So your letting your secret out Randall? ;) I'm really getting excited about the possiblity of a secondary battery pack. The possiblities are endless when you don't have to worry about the small capacity of the stock pack. I think realistically people could easily see over 100 mpg if they were driving semi decently and well over there if using extreme hypermiling techniques.

:Banane44:

Just a note... only one more day for me!! I'm sending payment to Mike tommorow morning first thing and then I'll be in MIMA/FAS heaven :D :Banane10::Banane21::Banane54:

I think realistically people could easily see over 100 mpg if they were driving semi decently

you said it all there, my friend

Randall

So your letting your secret out Randall? ;) I'm really getting excited about the possiblity of a secondary battery pack. The possiblities are endless when you don't have to worry about the small capacity of the stock pack. I think realistically people could easily see over 100 mpg if they were driving semi decently and well over there if using extreme hypermiling techniques.

:Banane44:

Just a note... only one more day for me!! I'm sending payment to Mike tommorow morning first thing and then I'll be in MIMA/FAS heaven :D :Banane10::Banane21::Banane54:

I'd do 100 mpg every trip if the terrain / distance allowed. :D

The booster / MIMA plan has been growing on me for a while, might have to throw my chips in soon. :)

Well if I were you I'd get on the waiting list asap. Mike has sold all of his kits and basically only has a waiting list going on right now. Last I checked there was only two people on it and mike has said he wasn't going to make anymore unless he gets at least 10 people.

The price is a little out of my range, and I'm pretty sure I could duplicate the aspects of the system I like on my own... $50k worth of EECE education, I'd hope so eh?

I'm pretty sure the scematics for the MIMA are open source. You could make one for your self... let me see if I can find the link.

EDIT: Yep, here they are. http://www.99mpg.com/resources/downloads/

I've seen them. :)

here is what i did for a fuel cut LED:

http://www.greenhybrid.com/share/files/1/8/0/7/FUELCUTLED.JPG

thats a 12 volt DPDT relay.