Quote:
Originally Posted by Ecky
I've been loosely following the threads, but I'm skeptical there's going to be a practical way to disengage the electric motor from the engine.
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'practical' is the yet to be seen subjective piece to the puzzle.
The current approach being looking at .. will be easier / cheaper on those who would wish to install .. however it has many issues to resolve with trying to package all the stuff inside the tiny space inside the IMA motor shaft core handling the torques , and ~6,000 RPMs .. ect.
Worst case .. if it doesn't pan out .. even if everyone else on the project looses interest .. I will eventually (years) just myself do a Inner/Outer Shaft to a Inner/Outer Double Clutch .. it won't have to fit inside the IMA Motor Shaft core .. Just replace OEM single Shaft that goes from ICE through IMA motor with Inner/Outer Shaft , and replace existing single clutch with Inner/Outer Double Clutch ... I know that will work just fine .. but it would be a bigger project on those wishing to do such an install/mod .. thus the current efforts instead.
That Inner/Outter shaft and double clutch method is already out there from OEMs and such ... and increasingly more of them also ... With luck , I'll find one that doesn't need much modification .. thus avoid getting a custom part machined.
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It was also interesting to see how the 3rd generation Civic 17kw IMA Motor (2012 model tested) is soo very close to a drop in replacement for the 2000 Insight 10kw IMA motor .. mounting bolts all the way around exterior fit exactly .. only 3 things make not a direct drop in replacement:
#1> Biggest ... The center shaft connection is off shifted slightly about ~2mm.
#2> coil/position sensor stick out a bit (~1/4") too much on the back (ICE side)
#3> It uses more coils and position sensors .. but confident that part at least would be easily resolvable in the software of Linsight .. which has motor control anyway.
Mudder & Peter both have already separately from each other verified the MDM and all the electronics all ave plenty of extra margin to be fine with 17kw IMA motor instead of the OEM 10kw .. .the current opinion/guess is that the ~10kw was a result of limitation of the OEM NiMH batteries .. not so much a limit on the electronics or IMA Motor.
If Peter's experiments that showed OEM 10KW motor and electronics can handle over 15kw .. if that same kind of surplus also applies the 17kw IMA motor design .. that same +50% would bring that 17kw up to about ~25kw.
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Of course the whole ICE/IMA disconnect thing is to avoid the ICE losses in EV-Insight Mode ... But .. Anyone with just MIMA or IMA-C&C can push their Gen1 Insight into EV mode once they drive it to fast enough RPMs to enter fuel cut .. or if they don't want to wait for fuel cut .. than they can use FAS to be in fuel cut at any RPM .. Although without Peter's more power modes you'd be limited to the OEM ~10kw .. and without the ICE/IMA disconnect you have all the pumping losses of turning the ICE while in that EV-Mode.
I don't often use that MIMA-FAS-EV-Mode .. but when I do .. I try to be in higher gears to keep the ICE RPMs low .. and thus keep the parasitic ICE losses low as well.
Attached Graph of Power Consumption tests I did of those ICE parasitic losses ... Power is as seen coming out from the IMA battery .. and just for ease of reference also attached the ICE RPM at speed for different gears graph as well.
Soo .. For example down at about ~2,000 ICE RPMs the ICE/IMA disconnect would save the EV-Mode roughly ~3,500 Watts to not have to drive the ICE's Friction and air pumping .. ~2,000 RPMs in 5th gear is about ~90kmph (about ~55mph) ... As we saw previously .. The Insight itself with extra battery weight needed about :
The Gen1 Insight Need to supply to wheels:
~8.80kw to sustain 60MPH @90%Eff = ~9.77
~5.95kw to sustain 50MPH @90%Eff =
~6.61
~3.87kw to sustain 40MPH @90%Eff = ~4.3
~2.42kw to sustain 30MPH @90%Eff = ~2.69
~6.61 + ~3.5 = ~10.11
With only OEM ~10kw .. that would mean ICE pumping losses limit MIMA-FAS-EV-Mode to a max of about ~50MPH on flat level ground ... A bit faster without the extra battery weight .. but not much ... The ICE losses are larger at higher speeds than the additional weight increases rolling resistance.