Prius section

[Moved from main index, 210823]

	Two electric motors and a gasoline engine, forever enmeshed in
	a whirling struggle for power, each seeking to gain the most while
	using the fewest precious resources -- their delicate dance
	constantly choreographed by a consortium of cold, calculating
	computers -- which in turn are mere slaves to a stream of arbitrary,
	capricious, and often downright stupid instructions from the loose
	nut behind the wheel.
     ... That's a Prius.

cars/prius-linkfarm.html -- Pointers to many resources about the Prius and other hybrids, many of them pointer-nests themselves. A thousand fascinating ratholes, but be warned that quite a bit of it is out of date at this point
cars/prius-flyer.gif -- A one-page flyer that simply points to here, for randomly handing out to people who seem interested
cars/prius-mods.txt -- Full list of modifications to this particular car, many of which are described in the pages below
cars/sweet/ -- Discourse on observing a "sweet spot" engine efficiency range, yielding improved MPG at mid and higher speed ranges with proper application. Take note of the 5-year update while reading, as it contains updated information
cars/HSI/ -- Toyota's implementation of the "sweet spot" display, along with several other important parameters, explained for best driving efficiency in the third-generation [2010 +] Prius. Somewhat theoretical so far, but will be refined as the community gains more experience with the car
cars/b-mode.html -- Lengthy explanation of what the "B" shift-select position is for, and some related quirks of the Prius hybrid system
cars/warpstealth.html -- Description of a subtle but zero-consumption high-speed "glide" mode that allows longer and more efficient coasting at speeds above 41 mph
cars/boost-hack/ -- Test-bench illustration of why regenerative braking can work at low motor RPM and still charge a high-voltage battery
cars/worktruck -- Small pictorial essay on handling large and/or heavy loads in a Prius, with particular attention to protecting the battery
cars/gps/ -- Making a relatively permanent mount for a GPS power cradle, using an easily-removable vent panel as the base
cars/nest/ -- Constructing a cozy sleeper-berth in the Prius, including a hack to run the ventilation system on very low power
cars/pwe/ -- An amusing hack to enable the power windows in a Prius without turning on the rest of the car. Also shows some details on safely removing the dashboard panels
cars/tpms/ -- A strange but functional tire-pressure warning system based on wheel speeds
cars/ect/ -- A circuit to read the raw output voltage from the engine coolant temperature thermistor, and convert it through a "linearizer" to a reasonably close mapping from degrees C to volts
cars/tachack/ -- How to install an aftermarket tachometer into a Prius, including notes on how tachometers work, how to test and calibrate them, and how to match the input circuitry to the car's signal levels if needed
cars/vvt/ -- Investigation of where variable valve timing comes into play in the Prius at highway speeds, including refutation of an earlier theory
cars/warmair/ -- Quick-n-dirty hack to redirect engine air intake from a warm air source rather than a cold one, with the intent of increased winter economy. Some test results posted within
cars/heatgames/ -- Second revision of the above warm-air intake, plus a detailed account of removing the cowl above the engine and installing a block-heater
cars/maint50k/ -- Changing the Prius HSD transaxle fluid, using the seekrit undocumented top fill plug accessed by shifting the inverter without having to drain, refill, and air-bleed its coolant. Other minor but useful preventive maintenance items discussed as well
cars/maint100k/ -- Prius maintenance checks and changes at 100,000 miles, including the inverter pump, coolants, tranny-fluid again, and a lot of testing and discussion on the remarkable longevity of modern parts and fluids
pix/prius-ferrups.jpg -- One method of tying in a UPS to the Prius 12V system. The 450VA Best Ferrups has 66 Ah at 12V inside, way more than the Prius battery itself. The right answer, however, is to stop messing around with this feeble, inefficient 12V nonsense and build a 10kW or more inverter that feeds directly off the HV battery. See also
cars/plugout/ -- A better solution for my own needs: a 3 KVA "plug-out" system, higher capacity 240/120 split-phase which needed several mods before being truly suitable
cars/naked/ -- The "Naked Prius" tech exhibit takes top honors at AltWheels 2005
cars/starthole/ -- How to fix a factory-assembly problem that can cause damage to the motor control harness, due to a starter blockoff-plate fitted backwards
cars/bp/ -- Friction-brake pressure monitor for the Prius, to show when fluid is sent to the wheel cylinders and causes kinetic energy to burn away as useless heat. Pix, circuit, discussion, etc.
In contrast to the never-past-vaporware Coastal product to display brake pressure, this is real and functional NOW
cars/prius-log/intro.html -- An attempted Prius diary / blog, which at this point will probably never be finished as such but serves to describe the runup to purchase and how the mods/hacking process began. See all the *other* Prius pages for what happened afterward...
cars/prius-rally-hints.txt -- A guide to high-mileage Prius driving technique, specifically aimed at participants in fuel-efficiency competitions
cars/mpg1105/ -- One way to document a rally course, geared toward MPG competitions. This one was actually held in May 2011, with Kimball Farm as the start and return point. This is oriented toward very clear direction so that drivers can concentrate on driving, as opposed to the occasional deliberate obscurity of traditional time/speed/distance rallies
cars/training/ -- Online Prius/hybrid technical training course material, including details on operation, safety, diagnosis, routine maintenance/repair, and a special section on 3-phase motor basics. Slides-format so far. An ongoing project
pix/quad-rings.jpg -- Some silly photochopped ideas for painting the plastic Prius trim-rings
cars/prius-curves.gif and cars/SAE-bsfc.gif -- A collection of power/efficiency curves. Kilowatt output can be mapped very nicely to RPM, so achieving high efficiency is as easy as watching a tachometer [which, unfortunately, you have to install yourself] and trying to stay at full torque output whenever the engine is running
pix/holyshit.jpg -- An early result from having better instrumentation in the Prius, and paying attention to state transitions, energy demands, efficiency curves, etc. With good weather and summer gas, I can reliably reproduce 70+ mpg on back roads -- not quite up to the level of the Pittsburgh paragons who achieved 110 mpg, but still well ABOVE the EPA numbers for this car
cars/storm.html -- Technical "voice of reason" piece on Toyota's recall woes around late 2009 / early 2010 concerning Prius brakes, unintended acceleration in some other cars, and a few additional overhyped issues
cars/brakerust.jpg -- Visual answer to the common "brakes grabbing" Prius complaint. The fix? Throw it in neutral to disable regen during a couple of stops; you'll clean 'em right off
cars/squirt/ -- A prototype injector monitor hacked together for the Prius, to see exactly WHEN we're consuming that precious fossil fuel
cars/nosquirt/ -- The opposite of "squirt": a simple mod to kill the fuel pump and let the engine conk out, which has certain beneficial uses and research implications
cars/imeter/ -- Installation of a prototype battery-current meter for the Prius, w/ pix, driver circuit, and discussion
cars/toyota-tis-sucks.txt -- A rant engendered by a rather horrendous "web experience" at Toyota's service-manuals subscription site
cars/ev.html -- Version 0.1 of the Prius EV-mode switch, hastily crocked in prior to its first real road trip [warning: largish pictures, very early webpage effort]
cars/Nomograph-plus-PSD.gif -- Rework of Graham Davies' original nomograph, showing the speed/torque relationships in the Prius planetary driveline and a simple schematic view of the system's construction
cars/meta1/ -- Thumbnails of my collected Prius/hybrid "slide show" as of 080418 [512 images in 8 meta-blocks, about 2.6Mb total]
cars/logos/ -- Exploring how to remove the Toyota logos from the front and rear of the Prius, and making the affected areas look halfway decent again. A brief adventure in automotive paint work
cars/dcty/bbt/ -- Follow-on to enhanced "safety bling" to gain greater day and night time conspicuity, as well as a certain "industrial hazard" aesthetic
cars/tires/ -- Having four new Michelin Green-X tires installed on the Prius, using a set of metal clamp-in valve stems for better robustness and reliability
cars/brk200/ -- Finally replacing the Prius factory-original front brake pads after close to 200,000 miles: clear benefits of regenerative energy recovery
cars/priexh/ -- Temporary patch for an exhaust leak on the Prius, and a look at how age and New England conditions have taken their toll

[A few more pages are pending, about the car's pandemic-era degradation and ultimate passing-on to where it could contribute to greater good]

Prius teardowns

cars/ginv/ -- In-depth mechanical and electrical analysis of the Prius inverter. Still in progress
cars/brkjob/ -- Discussion/pictorial of brake cleaning and service, with particular attention to the front caliper slide pins, and a section on how the rear drum self-adjusters work
cars/bodyecu/ -- Details on removing and disassembling the Prius "body ECU" and main connector/relay block from under the drivers-side dash
pix/prius-rheo.jpg -- Detail pic of the dash-lights "rheostat" in the Prius. It's actually a low-side PWM unit with a couple of other control leads
cars/prius-12V/ -- Details on the Prius 12 volt battery -- dimensions, type, the mounting area, voltage regulation, and quiescent drain
cars/dcty/ -- Simple removal of the "courtesy light" bulbs to avert 12V battery discharge from leaving a door ajar, with enhanced safety hints
cars/tb -- Pictorial rundown on the Prius electrically-actuated throttle body ...
  cars/tb/service/ -- and how to perform simple routine maintenance on it
cars/prilock -- Cleaning and maintenance of the Prius physical driver's door lock, to make it work better by removing the factory grease
cars/nest/ -- [Already listed above, but contains details on blower-fan controller]
cars/ipump -- Analysis of the Prius electric inverter-coolant pump, including why it tends to fail and need replacement around 100K-ish miles
pix/aw07/ -- Our Altwheels 2007 booth included a nice "exploded" layout of major Prius components and how they talk to each other. Includes the full text of functionality descriptions
cars/mfd/ -- Diagnosis of a subtle but common fault in certain Prius display screen units, detailing a fairly easy repair that can save $thousands$ for out-of-warranty '04 and some '05 owners
cars/coastEV.jpg -- What's inside the Coastal Electronics cruise-control based EV-mode widget
cars/batbox/ -- Examinations of a Prius battery at six and then twelve years old, to detect and head off any pending problem situations, and dance with its voltage. The battery cooling fan is also investigated, as is the backup brake power supply.  A minor cleanup and refurb happens at the 12-year mark
cars/wbear/ -- Story and autopsy of a failed front wheel bearing. It gave another thousand miles *after* becoming noisy and probably could have gone considerably farther before being replaced