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this one smacked me right in the face at about mile 383 on the odometer. let me come at it in a round-about way.

automatic transmissions are stupid. i do not say stupid to mean that i find the choice of their use to be dumb, but rather, that they cannot hold a candle, with respect to gear selection, to any competant and reasonably attentive one of us monkies behind the wheel. a short example: you are in high gear, on a flat/level grade, with no adverse environmental conditions to be terribly concerned about, and are applying only enough throttle to keep you moving at a constant rate of 50 MPH. a hill approaches. the hill is steep enough such that if you continue at your current amount of throttle, you will stall before cresting it. you are able to eyeball it, however, and see that a downshift is not necessary, provided that you apply 100% throttle, which will yield only a 18% decrease in speed at the crest. the hill *is* steep enough such that if you applied only 50% throttle, you would have lost approximately 45% of your speed upon having reached the crest. so you gas it and poot right on up without issue. if you had an automatic, you WOULD have experienced it downshifting. if you provided full throttle, you'd likely end up in 3rd for the first half of the hill and 4th for the last, or something similar, if you left the throttle where it was, it WOULD have kicked down into 4th at least... automatic transmissions are blind, they have no concept of the road ahead, no foresight, no hindsight, no prior knowledge of the road 1/3rd of a mile ahead, etc etc. any potential fancypants technology present in a vehicle to make the automatic act more like a manual is nothing more than an attempt at compensating for the inherant poor decision making skills of an AT. automatic transmissions are stupid.

i find that the brains in charge of the IMA are similarly stupid. aaron cake alluded to reaping the benefits of being able to extract a condition of both IMA assist and continue to be in lean burn.

i *WANT* a lever, very much like the lever controlling the hydrostatic drive of a snowblower or lawn tractor. this lever would give me manual control of the IMA. i want to be able to increase the amount of assist given by IMA without having to pump more gas into the insight's belly. if i see that hill coming, i choose to stay in 5th and apply full throttle in a normal car. the insight offers more -- it has this assist/charge thinger. with the IMA, i should be able to see this hill coming, smack the assist down to full-open, and then add only as much throttle as necessary to climb the hill. then, i would manually rear the lever back to charge as i descended.

i would like to be able to set the lever amidships to keep the insight from using charge/assist at all.

keep in mind, i have this thought without any intimate knowledge of the judgement process the ECU uses about how to employ the IMA, but it would be nice if this manual IMA lever could be toggled on/off. while off, it simply doesn't exist and the insight makes judgements as it sees fit. with it on, it would utterly override the ECU's decisions -- the ECU's decisions would be sent to the bitbucket, or otherwise dealt with gracefully, and i would have complete control of that lucious little torquebooster powered by the X # of hundred pounds of batteries sitting nestled ~14 or however many inches behind me.

those whose drives are hilly stand to benefit the most from this. if your drive involves several rolling hills with flat spots in between, and a large descent at the end; such that with a maximal assist/charge cycle on each hill, you lose 1 bar of battery, such that 50% of the way through the course of hills, you're down to 49% or less battery and it is force-charging you 2-3 bars in the flats, leaving you with 20% full battery at the end, at the beginning of the hill that charges you so completely that the charging shuts off 70% of the way down the hill, you would stand much to gain from manual control over the assist.

that's an elaborate theoretical path of travel, i admit, but consider how many times you've had to either do a delecate dance of dickering with the throttle just to try to get it to do some assist and stay in lean-burn, all the while wishing that you could get it to throw some full assist at you without you having to spend another 3" on the gas pedal and demolish the MPG you've been holding gingerly between your teeth, only to be at the stop light 1 mile down the road with a 94% full battery meter laughing at you. the IMA assist has to be toyed with and manipulated in the same manner as an automatic transmission and this is a shame.

i unflinchingly bet two pints of my blood that any hypermileage insighter could annihilate their current MPG trends after only one week of use of a properly implemented and functional manual-override IMA Charge/Assist selection mechanism. perhaps it is just me, but i cannot imagine that this has not occurred to others ( i admit i have not thumbed through the 17 pages of the turbocharging thread <G>), nor can i think of any modification i could crave more.
 

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Well, as for gear selection in an automatic, you can manually shift most automatics if you choose to.

Having said that, I don't agree with the implementation of the IMA control code in the ECU. However, manual control is not likely to be the answer. Using the IMA to avoid having to use gas while going up a hill is not efficient. The IMA stores energy that originally came from the gas motor. Maybe it's braking energy that would otherwise be lost, but it still came from the gas. If you use IMA instead of gas, you will have to use more gas later to charge it back up. Because the system is not 100% efficient, you will use MORE gas overall if you were to use the IMA system like that.
 

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It's possible that putting the IMA into full ASST and recharging it later off a lean-burning cruising ICE is more efficient than flooring both the ICE and IMA at the same time.
 

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I'm sure Honda engineers would have liked to have put a manual control for the IMA in the cars, but you have to consider one of the goals, a transparent drive train. Had the Insight required a driver to learn how to manually control another system think about it. How many would they have sold? Probably not enough to justify production in the first place.
 

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I agree that being able to manually override and control the IMA would increase the efficiency of the Insight in the hands of a dedicated driver willing to master this feature.

But it's much too complex to learn how to use well for 99% of Insight drivers.

We need someone to hack into the Insight ECU and start controlling lots of variables like this. Several companies make ECUs that replace or Piggyback the OEM ECU of many performance cars to increase performance....
 

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Ah yes, the never ending debate of how the IMA functions should / could be made better. :)

What is almost always lost sight of in these threads is the very limited available energy in the IMA pack to begin with. Maximum MPG via the Honda system comes from learning how to maximize the gas engine's economy. The IMA simply makes sufficiently extra power available for rapid acceleration when needed.

Basically its a very undersized maximized for MPG gasoline engine with an electric supercharger.

There are _major_ losses of efficiency in the conversion of energy forms chemical, mechanical, electrical. Any wishful thinking in regard to being able to convert and later recover energy forms must also include these losses. So far they have always calculated and been proven to be losses not gains or break evens.
Yes you can recover some energy in a cost effective manner that would otherwise be counted as a loss, but the biggest savings is to expend less energy in the first place.

I routinely drive in the hills and mountains of east Tennessee and wish for a feature such that I could delay a forced charge. I could anticipate an upcoming down slope that would more efficiently replenish the IMA pack. However, in carefully observing the instances that such a choice would be beneficial its clear that only a tiny fraction of the energy consumed by the Insight could be saved for all but specific and unusual driving patterns.

Insighter's will do much better if we stay focused on MPG and drive as the indicator dictates within what traffic and terrain allow. Having to divide your attention between MPG and IMA recovery will likely result in lower MPG because of insufficient attention given to MPG and the _very_ small amount of equivalent "MPG" energy recoverable from maximizing IMA.


Also see this recent thread:

http://www.insightcentral.net/forum/vie ... 6430a3885c


HTH! :)
 
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