Let's get technical: Tuning the ECU for mpg

[Spencyg]

How do you intend to actually control the A/F ratio of your burn cycle with the wideband 02 controller? I was under the impression that the LC-1 could output an analog signal to a stand alone, piggyback, or datalog system, but couldn't by itself do anything for engine management....let me know if this isn't true, as it could be a very interesting alternative.

Spence

[gasssaver87]

my volvo has a little screw you can turn on the mass air flow sensor to adjust the air/fuel ratio...

[Spencyg]

What year is the Volvo? The mass airflow should just be an input into the computer, along with that silly O2 sensor which will correct any attempts to lean out a mixture (for Nitrogen Oxide reduction purposes)....if its an older FI, than maybe this isn't the case. That would be cool...

Spence

[usedgeo]

Originally Posted by Spencyg

How do you intend to actually control the A/F ratio of your burn cycle with the wideband 02 controller? I was under the impression that the LC-1 could output an analog signal to a stand alone, piggyback, or datalog system, but couldn't by itself do anything for engine management....let me know if this isn't true, as it could be a very interesting alternative.

Spence

Go to the Innovate web site. Go to support. You can print or read the manual. It is on page 17. I was sort of reading between the lines. It sure looks to me like there are instructions for connecting it to your ECM. I have two sensors and the second one is used for trimming so it might set a code if it never changes state. Another here said a simple circuit can take care of that.

Bear in mind I have not done this yet.

http://www.innovatemotorsports.com/support.php

[kitcar]

A lot of Dodge guys have done some work with the ECU and "fooling" it to run a leaner mixture. What I've done in the past is add a variable resistor to the IAT circuit to fool the thing into thinking it was seeing a different temperature. In real cold weather (0 degrees) I could actually get the thing to stall from fuel starvation.

The primary use of it is to increase HP by tuning the mixture. But with high gas prices, one could also tune for mileage.

[CoyoteX]

I have a LC-1 installed in my car and you can easily change lambda on the sensor to something other than 14.5:1. My car is way out of tune so the leanest my car can go normal cruising is 13:1 but I can set the ratio to 12:1 and the car happily adjusts the fuel up to reach that. I have it set at 14.5:1 right now but seeing as how it can't get that there is no point in me changing it.

Wiring it in the car is pretty simple, just switched power, ground, and the o2 signal wire. I already had all those under my hood so I didn't have to run any wires through the firewall to hook it up.

Won't be long before I have time to install the megasquirt into my car then I can tune it for anything I want to try

[Telco]

If you really want to run lean, consider changing computer systems. The two I like are Megasquirt which is a cheap, do it yourself system that allows the use of a wideband and is very cheap to buy in comparison to many aftermarket systems. Only bad thing is, it's batch fire injection although they are working on a sequential method. The other one I like is Big Stuff, which is more expensive but also offers sequential injection. With a wideband you can get an accurate measurement from 12:1 to 20:1 A/F ratios, and have total control over how and when.

Hope this helps.

[Spencyg]

Very interesting. So the LC-1 can actually output a modified signal to the ECU? This could be a very powerful tool to those looking to tune to a leaner burn condition. It must act in a similar (though seemingly much more advanced) manner to the unit provided by eagle research (see the link above). I have done lots of research on stand alone systems such as the Megasquirt. They all have their benefits and drawbacks. The biggest drawback I see with ALL stand alone systems is that they require the use of their own sensors. This means you can't just cut into the stock harness and hit the ground running....you actually need to convert the entire engine management system over to whatever the system of choice requires. This is a serious drawback for those of us wanting something that is nearly a plug-and-play setup. Megasquirt is an odd duck. Its entire system is based on "open source" knowledge and technology....from the board design all the way up to the system programming. I'm not an electrical engineer, and I know when I should count my losses and run. This is exactly what the Megasquirt would cause me to do! For those interested, do some research on the Greddy E-Manage Ultimate....its a nice compromise between an LC-1(I assume) and a full stand alone (such as Megasquirt).

Spence

[CoyoteX]

There is a guy that is making a basically plug and play megasquirt that fits metro/swifts. The only thing you have to do is run a vacuum line to the computer. The rest just plugs in as is.

[DRW]

Hello! Interesting thread. I think I'll subscribe.