NHW11 hacks

This list gives some ideas of what I'm using, tested, and my speculations:

	Column 1	Column 2	Column 3	Column 4	Column 5	Column 6
0	Modification	Status	Price	Performance
1	1 kW inverter	use	$100	4-8 hr	Used 1-2 times per year	2-20 hours and cabin 110 VAC
2	2" trailer hitch	use	$200	2 hr	Used 1-2 times per year	oversized loads
3	rear wheel shims	use	$10-25	2 hr	Used constantly to reduce tire wear and drag
4	front camber bolt	use	$10	1 hr	Used constantly to reduce tire wear and drag
5	Type WS	use	$25	1 hr	Reduce transaxle drag	change 30k mi.
6	Passive window vent	use	$50	1 hr	Ford Focus passive vents siliconed reduce summer solar load
7	block heater	use	$50	1 hr	Saves ~1 minute of warm-up
8	Lower radiator block	use	$5	1 hr	Moves effective temp. up ~10-15F when temperatures are freezing
9	ICE themister hack	tested	$10-100	16 hr	allows Stage-4 about 3 minutes early
10	Remove seat	tested	$25	2 hrs	nap board and larger loads
11	larger diameter tires	use	$200	improves handling	no significant mileage improvement	expands hybrid speed range +1-2 mph
12	Graham scanner	Yes	$100-200	record engineering data for analysis
13	GPS mouse	use	$50	combine with Graham data for analysis
14	data cable	tested	$10	carries engineering data from engine to cabin
15	flat towing	tested	$300	allows high-speed	NHW11 towing behind RV
16	XM radio	discon	$75	replaced by iPod FM modulator
17	iPod	use	$50	quality content	lower cost
18	concave mirrors	use	$10	mounted on rear view mirror to cover blind spots
19	transaxle heater	broke	$40	JC Whitney units	junk

.
You'll notice there is a mix of efficiency and utility modifications. If the NHW11 can provide additional utility, the quality of life is improved and one's life is 'less cluttered.'

The following have not been tested but are offered as ideas:

• replace with NHW20 modules - the existing NHW11 modules have weak terminal seals and I would like to replace them with NHW20 modules when the time comes.
• solar reflector shades - like the removable kind but mounted using silvered, mylar film, more easily deployed front and rear
• rain closing, cracked windows - when cabin temperature reaches 90F, the windows will seek a 1" opening and close if rain starts to fall
• fold down rear seats - available in the Japanese and European NHW11s, this provides space for long loads (fishing poles and lumber.)
• glass-pack muffler - a common performance hack, reducing muffler constriction may improve exhaust scavage and engine performance at highway speeds and hill climb
• turbo drive - an uncommon hack, try to recover some of the heat from the catalytic converter reactions
• electric A/C - trunk mounted, 110 VAC air conditioner, <5,000 BTU, driven by inverter to avoid engine driven compressor
• exhaust heat capture - tap exhaust heat for cabin HVAC using absorption cooling cycle
• solar fan - helps force hot air out in sunny conditions
• load driven cruise control - keeps the ICE in efficient RPM range by allowing larger speed variations
• auto "N" - shifts to neutral for automatic glide in no brake, no accelerator operation
• O2 hack - extends initial start, battery EV mode from 30-45 seconds to 1-2 minutes. NOTE: needs testing to confirm no risk to catalytic converter, some increase in initial pollution likely.
• fuel pump hack - turns off fuel pump to force ICE off for EV mode (with warnings!)
• docking curb - driving car into curb provides AC power for block and cabin heating and cooling and traction battery topping.
• advance docking - provides HVAC so vehicle exhaust heat can be used for house heating as well as house power
• second power inverter - a second NHW11 inverter is micro-processor driven to provide up to 18 kW of pure sine-wave, emergency power from traction battery, part of advanced docking system, transportable in trunk but operated as stationary power system
• rear wheel electric drive - 5th wheel using 2" receiver
• alternate fuel system - partial combustion system using water injection provides cooled, combustible, gasious fuel to engine air box to replace gasoline during high-speed cruise. Carried on 2" receiver and microprocessor controlled, substitutes charcoal for gasoline.

Edison explained that only 1 out 100 ideas every pan out. When asked how he explained being such a successful inventor, he answered, "Have lots of ideas."

Bob Wilson

 

I thought about the sealing TIS and the visible O-rings seen in the terminals and realized that short of trying to rebuild the terminals, this would remain a permanent weakness of the original cells. The normal, high pressures forces the water, actually the H{2} and O{2} out the terminal seals. We can replace the lost water but without fixing the terminal, they are just going to fail again.

One alternative is to drill out the pressure valve and install plumbing to make them into a wet cell instead of the current mat. Then I realized that the maximum voltage between the end module, pressure valve assembly would be ~375 VDC. Given KOH conductivity, the wet cell assembly would need the same electrical isolation.

Another alternative would be to try and rebuild the terminals. The key is finding an O-ring supply and someway to drill-out and replace the existing terminal fitting. But for this to be practical, it needs a steady supply of failed NHW11 modules to rebuild and market to sell them. IMHO, this is not practical but I still think about creative ways to solve this problem ... perhaps packing with epoxy impregnated thread ...

Not published before, I've come to the conclusion that after the current inventory of NHW11 modules are worn out, the best answer for individuals is replacement of the 38 modules with NHW20 modules. The NHW20s are better designed with slightly better electrical characteristics.

I've only fitted the rear windows. What I noticed is the NHW11 and Ford Focus have very similar body shapes and window sizes. So I ordered a set of window vents and learned the front won't work. However, the rear ones did after I trimmed a little plastic and used a silicon sealant to hold it in the window frame. It is not perfect but it does seem to moderate the heat and I don't have to race the random rain storm approaching the parking lot.

Still on my list. Hobbit achieved part of the solution with his window hack on the NHW20. In a world of competing interests ... well at least two of us know local warming is still important.

I'm hoping our lists may inspire others to join us and tackle one or more of these enhancements. Better still, use their new eyes to identify new opportunities. The NHW11 has known limits but these vehicles are available for very reasonable amounts. Yes, there is a risk of failure so I would not recommend it or any older car without a backup. However, we have a growing knowledge base of how to deal with them by home mechanics.

Between you, Patrick and my efforts, we're helping to mentor new owners of older NHW11s. This is a good thing as the NHW11s are excellent 'green rods' because they share so many systems with the NHW20 and ZVW30. <grins>

Bob Wilson

 

Welcome to PriusChat and an excellent first posting:

Yes. The Prius cruise control consists of three resistors in series and four switches. If you'll check the message archives in the Yahoo Group "Prius Technical Stuff" I believe you can find the resistor values. One side of resistor series is grounded and the other connects to a ping "CCS", pin 16 of connector "H14" of the hybrid vehicle control ECU:
Prius Hybrid Vehicle EUC

You may be able to get a salvage unit but this is not something I have much experience.

I would recommend changing the transaxle oil pretty soon. We found that the first change needs to be done early. You're welcome to review some of my data:

2003 Prius

Sounds like a nice find.

GOOD LUCK!
Bob Wilson

 

Let's take any follow-up over to the ZVW30 forums but the short answer is:

• look up: EZ-shim
• front camber bolts are described in Vol 2 of the ZVW30 maintenance manual - you'll need to bring the four-wheel alignment values here before we can discuss which ones would be used
• flat-towing - is specific to our NHW11 that is now well beyond the Toyota warranties. The ZVW30 is still under the 3/36000 and 8/100000 warranties

Bob Wilson

 

I'm having a senior moment today. Did you post any photos of the hack?

Bob Wilson