Hi All,

Enough with the intro topic. Another glass of wine and it's time to get serious. Does anyone have any experience with re-programming the HAH computer?

While driving down from NJ to NC, I noticed an obvous improvement to the engineering of the car. It's okay, I'm allowed to do this, I am an Engineer.

Anyway, something that annoyed me a bit was that the 'I hate W' (eco) light would go out when climbing a light grade. I had the cruise on of course. What I have noticed about cruise control is there are two kinds, ones that track the set speed very well and ones that uh, well, don't. The HAH's does, which I like but in the case of maximizing full economy I am thinking some slop (that's a technical term) might be okay.

One key to fuel economy is constant fuel delivery. Economically, it is better to feed a constant amount of fuel to the engine over time, slowing on the uphills and accelerating on the descents. The problem is, drivers do not like the deceleration on the uphills and cops don't like the acceleration on the downhill .

Imagine a decay ratio of about 1 miles per hour per 10s. Not very noticable over the short term. I noticed the IMA does not kick in unless I am accelerating with some spirit. What if the IMA carried me over the short hills? I mean 16 extra ponies may keep the gas engine in 3 cyclinder mode. Certainly if the battery reserve fell to a certain level the full engine could be engaged.

Thoughts?

David

This was kicked around last summer, I think, by some folks. The course code is very likely a variant on C, and could probably be hacked.

Also being a EE, albeit from the harware side, I can think of several resasons not to do it:
- Think about your responsibility to others as an engineer. You are looking to dork with a very tightly (and well!) integrated hardware-software-human interface which you are (probably?) not an expert in, nor have any particular knowledge of. Can you safely guarantee yourself and your passengers and the vehicles around you that you robustly found and regression tested every scenario? Things like 'just adjusting the setpoint for IMA' are rarely ever that simple...we all know that from hard experience. It's one thing to have a reasonable expectation of success when adjusting your own brakes, engine repairs, etc- the procedures are well-documented. There is no such analog for re-coding the ECU.

- IMA does kick in alone in eco mode on very light grades when the ECU decides it can handle the added load without the other 3 cylinders.

- ECO, strictly speaking, only means the car is getting over 30 (nobody really knows) mpg at that moment. 90% of the time, that means 3cyl operation, but not exclusively.

Having said this,

- If you happen to be a Honda programmer, my apologies.
- I and many others love the idea of a selectable 'constant load' CC as opposed to 'constant speed.' Like an amplifier that can be selected for constant power output or constant current consumption. IIRC, Ford said they were looking into this after the 'hybrid expo' day last fall.

Although not an Accord, there is already someone who has hacked into the Honda IMA code. His work is on Honda Insights. It allows the driver to control the IMA system.
www.99mpg.com

Mike Dabrowski is very skilled at what he does and he will be a speaker at Midwest Hybridfest 2006 this summer. (www.hybridfest.com)

Eric Powers

MHG Organizer - www.MadisonHybridGroup.com
Hybridfest 2008 - A Hybrid Electric Car Show and More! www.hybridfest.com
Madison, WI July 19 & 20, 2008

Eric,

Thanks for your response. The info on MIMA is interesting. I am thinking, there is hope.

Navy,

I find your response boring and lacking any kind of vision. Yes, there is some risk to tampering with the system, but nothing good is ever accomplished without some element of risk. Just ask Neil Armstrong. The risk in this case is not to life an limb though, it is to property damage. I imagine it would be easy to make a mistake and damage the IMA.

The notion that the Honda engineers are absolutely correct in every choice they made is proposterous. One only need look at parking. Pull into my parking space and the autostop kicks in. Slide the shifter into park while my foot is on the brake and the engine starts??? WTF? How does that make sense? It is such an obvious FU as to be laughable. You sound to be almost a Honda shill.