Honda Insight - Haltech ECU for More Constant Lean Burn
 

I watch a lot of Mighty Car Mods, which is an Australian YouTube channel where they do mostly cheap and DIY modifications to cars. They like to replace the stock ECU with a Haltech ECU so they can further control all aspects of the engines performance.

I want to see what can be done for the Honda Insight to further raise the MPG by programming an ECU to run in lean burn mode more consistently. No dropping out of LB to purge, enable LB at lower RPM, etc.

When I had the Passat, I messed around with tuning the ECU for better MPG and performance. I was able to raise the horsepower from 150HP to about 230HP where the injectors couldn't keep up with the amount of power I was going for under boost. I also went from 29MPG stock to 48MPG highway by running my car really lean under no boost and using hypermiling techniques.

Is anyone else interested in getting an ECU and giving this a shot? I'm thinking of keeping the IMA system but finding a way to fully control it for max power at take off and lower gears since this is where the Insight loses most of its efficiency.

Over on Insight Central, Julian Edgar is running an aftermarket engine control system.

Turbo, w/a intercooling, alternator and MoTeC management - Insight Central: Honda Insight Forum

This is leaving out a lot, but what he found was that running very lean was actually very difficult, especially the transition in and out of lean burn. His mapping doesn't go anywhere near as lean as the Honda factory ECU because it resulted in a very undrivable car. You might want to sink your teeth into his thread though, as there are a lot of other factors, other than air fuel ratio, that could help economy.

Thank you for the information and the link!

I did a quick read over about 20 random pages from the thread. To me, it looks like the turbo and the lack of IMA might be the reason for the 51mpg VS 65mpg the OP of that thread saw(Not sure if that is the average MPG the OP eventually got the car to stay at). I'm going to bookmark the thread and read it post by post because there is a lot of valuable information there.

The big issue I see with the way he went about it was adding an alternator. As a lot of us know, an alternator consumes a decent amount of power. There have been people who have done tests with and without an alternator, which raised MPG by up to 10%. The other issue I see is the turbo installation. A turbo forces more air into an engine, which causes the ECU to add more fuel to the engine, lowering your MPG. Let's say the alternator he used(90 amps) took 10% from the cars economy, that is 6.5 miles per gallon as he states he got 65 mpg before. That put's the economy at 58.5 mpg theoretically. Then add the turbo, which causes more fuel to be consumed, and you are down to a level of fuel economy that he saw, 51MPG. Just using the DC-DC converter instead of an alternator and omitting the turbo, I am pretty confident that similar, and likely higher MPG can be reached.

If/when I do an ECU upgrade, I won't be using a turbo(On this car, the one I'm buying for an engine swap will be getting a turbo). I am pretty confident that controlling ignition timing, AFR, etc, can be changed to get more fuel economy, especially when combined with a larger battery and a MIMA-like system.

I'm going to reach out to Haltech and see what can be done for this application.

I reached out to Haltech for a potential ECU kit sponsorship for both this project and my 1.8T engine swap project.

Unlikely, but.... Fingers crossed!