Hymotion and 52 MPH EV Mode -

I'll be really interested in hearing exactly what that mod is in
their case, and how much thrashing it takes to correct from the
error state it lands you in once invoked.
.
_H*

 

That is very cool, and great you can combine it with your existing Hymotion battery pack. How much does the mod cost?

 

You will love it. I've been using it for a month or so now. I can go around town in pure EV mode. With the ability to go 52 MPH you don't have to feather the gas to maintain EV mode. I usually get about 10-15 miles in pure EV depending on the temperature. I have learned that batteries are much more efficient when they are warm. I would guess that they have twice the power when the temperature is above 50 degrees. I also learned never hit the button when the temperature is below 10 degrees. You can go, but you have no power.

Enjoy, I think it is a fantastic mod. You will need a Scangauge or something to clear the codes as it does light up the dash when you push the button.

---Kent

 

Very typical results and yes, I have hit the button on accident when my hand slipped off the turn signal. I'm not more careful.

Keep posting your results to send them to me directly. I'm glad somebody else is working with the Forced Stealth Mod. By the way, I paid Carolyn's for the information and performed my own installation with the parts they supplied.

---Kent

 

Is that implying that you're deliberately not telling us what
the mod does?
.
_H*

 

Yep, that seems about right.

I would be very careful draining the stock battery after the Hymotion gives out. Some people have reported that it can be a bit fickle about deep discharges (like after running out of gas)

 

Who is the comment referencing? The mod forces the engine to not run allowing you to use the Hymotion in pure EV mode.

 

Yes. If you read the National Labs (I think it was Oak Ridge) PHEV Prius tests, and look at the charts, you can see that they got somewhat less than 4 miles per KWH on average.

Edit: Nope, Idaho. Here's the page with test results:
http://avt.inel.gov/phev.shtml

Now when I take the PHEV Prius data and do a rough cut at average miles per KWH, I get a little over 4 combined city/highway. Either way, it's about 4 miles per KWH.

 

ibcs,

Your weather is a little warmer than mine. But, what happens when you run your heater? Have you tried it at the lowest fan/ temp. setting? Does the engine just not come on at all?

George

 

Hi George,

If you push the button you don't have any heat from that point forward. The engine will not come on until the car power is cycled. If you let the car warm up you will have heat for a little while. I installed heated seats, so I use them heated seat for warmth and don't worry about the inside temperature. I do sometimes turn on the front defrost to avoid fog on front window. It works without s warming up the car.

---Kent

 

I suspect, Hobbit, that not all engineers are as happy to share information as you are.

I believe that Carolyn is probably retaining some I.P. against this switch, although I suspect it has something to do with turning off either the fuel pump or the injectors...

Regards,

Nikki.

 

I would be happy to share, but I agreed with Carolyn's Garage not to disclose how to install the hack. I'm a man of my word, otherwise I would be glad to help others. I love the Prius, but I do believe in helping small businesses like Carolyn's.

---Kent

 

Absolutely- I understand as a small business owner how important it is to not shoot yourself in the foot by giving away trade secrets!

I hope you'll not mind though if some of us speculate about how it's done Unless that makes you feel uncomfortable - in which case I'll shut up

Nikki.

 

Are you kidding, I speculated and went through the Prius hardback manual for days trying to figure it out. I'm cheap to the bone, but I'll admit I paid for the information and I do really enjoy the button. Before anyone asks, I paid $200 for the instructions and the switch.

---Kent

 

I think you're missing the point. *I* have a fuel-pump cutoff switch
in my non-Hymo car and can duplicate one of possibly several engine-out
conditions which do indeed let me thrash the battery beyond normal
limits, but it doesn't seem like that's any kind of "trade secret"
material. I just wanted to compare notes on other peoples' approaches
to the same problem. Remember that while everyone knows what the EV
switch does, people still pay money to Coastal and others to have a
switch installed or a pre-made kit if they don't feel like DIYing.
That's fine, it lets people choose their own methods. I'm just
disappointed in seeing a failure within our normally open community
in the information-sharing it's become famous for, and with the
excuse that it's withheld for someone's financial gain [carolyn or
anybody else, doesn't matter]. That's just wrong, for what should
be such a simple thing.
.
I still think that putting the car in that kind of error state is not
really a good thing; it seems amazingly klunky to me but if that's
what people are willing to do, there are several ways to go at it.
.
Maybe I'll finish up my "stupid-simple fuel-pup cutoff switch page"
after all, as it originally seemed too trivial to bother with. I did
discuss its usage a little in my summer trip writeup, in fact, but
only to help with some long stretches of neutral-coasting.
.
_H*

 

Hobbit,

I think I'd look forward to seeing that page! Although, I do agree with you (on all counts) - I am unsure if the high-speed stealth is a good idea. In my PHEV, it's possible to use plug in energy before any ICE energy is. Sub 31mph of course it's possible to use EV mode to absolutely force the ICE to stay off - but above this the ICE can help quick acceleration and then tends to just spin (burning no fuel) at high cruise speeds.

Given the roads I drive on are quite full I think it's a better solution for me. I never know what is around the next corner....

What are the implications of forced high-speed stealth on the transmission? I would be interested if I knew I could exit it without rebooting the car....

Nikki.

 

If it comes to that, I'm not sure it's a good idea to run the car for long distances without the transaxle oil pump running. This oil pump is driven by the engine - the oil pump shaft runs through the centre of MG2 and slots into the far side of the planetary gear set.

I haven't (since I have not undertaken any PHEV mods) been able to run the car more than a mile or so at 29mph*, so I don't know if the car would start the engine to stir the transaxle oil if you drove for a long distance in regular EV mode. It may not do, as the car was never designed as a PHEV. It is of course possible to run pure-electric up to 42mph; again, the battery won't last long enough to see if the engine would be started only to run the transaxle oil pump.

* for some reason, factory EV is limited to 29mph in the UK. This may be due to the default speed limit of 30mph in built-up areas if no other speed limit is indicated.