35 mph EV barrier

You might want to read this thread to see if any unintended consequences
are mentioned:

http://priuschat.com/forums/gen-ii-prius-audio-electronics/394-speed-sensor-defeat-update-4.html

 

The upgraded plug-in systems allow for higher speeds so why would you want to increase the speed on the the OEM system?

 

100% true but in the OP's defense...what if the owner doesn't have $7k+ to spend on a plug in system?

 

Then why would you want to increase the EV speed? You shouldn't be driving in pure EV mode in most situations and going freeway speed in EV mode will get you all of about 1/4mile before it needs to be recharged. lol

 

to save on gas??? lol.... me personally, since my baby (acura legend) gets 17mpg, I am more than happy even getting 35-40mpg on my prius...

but some want more.....I personally wouldnt wanna drive in pure EV mode.....the car has no balls as is, forget straight EV LMAO!

 

But you will LOSE gas mileage by driving in EV mode, especially at high speed. The Laws of thermodynamics cannot be bent. lol There are very few cases that forced EV mode at high speed would help mpg.

 

call me an idiot, but at ANY speeds using no gas = unlimited MPGs no??

if the car ran in EV mode onlly (assuming it was possible) then how could it not get better MPG since its not burning gas at all?

 

Let me answer your question with another question. Where did the energy stored in the battery originally come from?

The answer 95% of the time is gasoline. So you burned gas and turned it into electricity. You have suffered a conversion loss when you did that and transformed some of that energy into heat. Now you will use the energy to propel the car and that energy will have to be replaced. Unless you are going down a long hill and can regenerate energy through the braking system you will replace that energy with the ICE which runs on gasoline. So as you can see, the energy stored in the HV battery came mostly from gasoline so using that energy to propel the car completely is a huge waste of energy and should only be used to assist the ICE and not as a sole power source.

 

I should have stated that the real improvements in efficiency in the Prius and most other hybrids comes from the Atkinson Cycle engine and the fact it can turn off when coasting or at stops as well as the regenerative braking system. The HV battery system is mainly there to supplement power as needed for acceleration because the Atkinson Cycle engine is rather weak on its own.

 

lol wut? I get what you mean and me being a dumbass, forgot to realize the energy has to replenish and it replenishes through the gasoline motor so there is no way to NOT burn fuel

 

Nah, you're not a dumbass. It is a common misconception with hybrids so there are millions of other people who forget or didn't realize where the engery comes from. That is why we have that question in our fuel economy questionnaire. There are so many people who try to drive in EV mode to save fuel. lol

The OP may have something else in mind though. I only added my question because other people may be lurking in the thread who would have been misled otherwise.

 

I already said it is possible. The plug-in kits can do it.

Honestly if you have to ask this question I am not sure you are qualified to perform a plug-in upgrade. I know that sounds harsh but there is a lot that goes into it besides speed caps.

 

driving faster than 35 MPH on EV only is possible if you accelerate gently. a stock hybird battery has only enough power to accelerate the Prius to 42MPH before running out of juice and force the ICE kick on to recharge. during this recharge you'll get about 30-35MPG until the stock battery has been recharged back to normal level. this may take a couple of miles. the overall mileage with depleted battery will be far worse than keeping the battery at normal charge.
the Prius doesn't accelerate well with electric motor even with plugin conversion. however, it can sustain EV at higher speed than a stock Prius.
I think the OP meant how to accelerate past 35MPH in EV only. it's not that simple and cheap. if it was, everyone will be doing it. this is a Prius, not a volt. it's going to take a lot of money to make it drive like one.

 

All you have to do is cut power to the fuel pump, then it will let you go 52. Just about anything else is a lot more work.

 

1, stock battery doesn't have enough power to let you go from 0 to 52mph, 41 maybe, 43 if you're lucky, beyond 45 forget it.
2, creating an open circuit on the fuel pump will light up your dash like a Christmas tree.
3, once you've created an open circuit, you need to power off then on the Prius to reenable the ICE.
4, the distance you can travel on EV is way less than 2 miles
5, you'll run the risk of depleting the HV battery below the recommended SOC.
6, EFI hack is only recommended on cars with contactor type of PHEV and not even recommended on converter type PHEV.
If you ignore all the precautions, then yes, pulling the EFI fuse is the easiest way to bypass the Gen II's 34mph and Gen III's 25mph barrier. If you're gonna do it, at least get a cheap PHEV kit. That way, if you ran down the HV battery below 40% SOC, at least you'll have a way to recharge the HV battery back up to safe SOC.

 

Exactly the point. The car will go 52, because it thinks it is out of gas, but you need to have some serious juice stored up in some sort of PHEV pack to have any sort of range. But it is the quickest route for the original poster to break the 34 mph EV mode barrier, and was the method used by some of the early PHEV systems. The modern systems have person-years of development in SoC spoofing, piggyback ECUs, etc, and would be a lot more work for someone to duplicate DIY if starting from scratch.

 

Really? There are non hybrid vehicles getting that now.

 

But they probably aren't driving in busy Long Island traffic.