MSefi.com read only forum (Jan.15,2018)

All,

The Innovate LC-1 wide band ego sensor controllers are very popular for use with MegaSquirt. There is quite a bit of info on these forums for using this system, but some of it is old, and some of it is just wrong or contradictory.

For the latest and best info, please see DIYAutoTune's guides, here:

Wiring: http://www.DIYAutoTune.com/faq/faq.htm#LC1wiring
(or here for the Innovate LM-1/LM-2: http://www.DIYAutoTune.com/faq/faq.htm#LM1wiring)

Configuration: http://www.DIYAutoTune.com/faq/faq.htm#innovate_config and our own info on calibrating the AFR table here: http://www.megamanual.com/mt28.htm#oa

Also, check the Innovate manual: http://www.innovatemotorsports.com/supp ... Manual.pdf
and support site: http://www.innovatemotorsports.com/support.php

Lance.

Thanks for the usefull info Lance cheers.

One quick question, A friend is lending me his unit , he says that once the megasquirt has been set up I don't need, as it is only needed for the initial set up and tuning. Is that correct?

Rob

Bobbyspit wrote:Thanks for the usefull info Lance cheers.

One quick question, A friend is lending me his unit , he says that once the megasquirt has been set up I don't need, as it is only needed for the initial set up and tuning. Is that correct?

Rob

Yes, and no.

The wide bad sensor is critical for setting the fuel tables. You need to know what the engine needs to be happy, and the sensor is the only reliable way to do that. That's what dyno tuners use to adjust fuel mixture on every vehicle - except diesels. I don't have MS yet (soon), but from what I'v read the software can use the WEGO to populate the fuel tables.

EFI can be run in two basic modes. Closed loop means the the computer will get feedback from the WEGO sensor and adjust the fuel mixture according to that. That keeps the mixture more accurate, as it will help adjust for changing weather conditions and changing engine parameters. Generally speaking, closing loop is only used at lower rpm's and lower throttle positions. Helpfull for part throttle cruise to decrease emissions and increase fuel mileage.

It can also run on open loop, without the input from the WEGO sensor. The computer runs off the fuel tables without the benifit of analyzing the exhaust gases. It will use the fuel tables, and make adjustments according to the altitude, air temps, water temp, etc tables. Not quite as accurate while cruising, but certainly more than adequate for most applications. My current EFI system runs open loop without any problems at all.

Bspit,

You likely don't need the wide band after initial set-up, as long as nothing else changes.

However, if you are an moderately experienced tuner, you may not need a wide band sensor at all. I rarely use wide-band feedback in the vehicles I tune, and they run great. Remember that millions of people tuned hot engines and race engines with carbs/jets/etc. long before wide band sensors became available.

If you are comfortable tuning carbs without wide-band feedback, then there is no reason you won't be just as comfortable tuning EFI without wide-band feedback.

Personally, I wouldn't use any form of wide band feedback to permanently alter the permanent VE tables on any engine I tune. There's just too much to go wrong with a sensor for me to feel comfortable with that approach. If I look at the wide band feedback, it is in a datalog, and then I make sensible alterations to the VE table manually. Others do use automated mixture correction and are happy, though.

Wide band sensors are a tool, and like any tool, they (and their wiring) can be misused, poorly calibrated, defective, unreliable, operating outside their proper range, and sometimes just plain wrong. (Wide band sensors are much, much less accurate than narrow band sensors in their intended operating range, which is one reason why most manufacturers still use narrow band sensors in OEM applications.) You have to take a wide band sensor/controller's output with a big grain of salt, and use it as just one of many pieces of the puzzle when optimizing your tune.

Finally, a wide band sensor cannot 'tune' your engine for you. What it can do is alter your VE table to match your AFR table. If your AFR table is optimum, then you are done. But there is no way to be sure the AFR table is optimal without some other measure of performance (such as quarter mile times, lap times, G-meter, etc., etc.). But to get the most out of your engine, you still have to tune, it's just with a wide band sensor you get a measure of the AFR, and there are more 'rules of thumb' out there for what the optimal AFR should be (though these rules of thumb may not be right for your engine, and the error in the measurement of the actual AFR might be quite high).

That being said, a properly set up wide band sensor/controller can be useful to a beginning tuner to get them 'close', as long as they keep the limitations in mind and use a lot of common sense in interpreting the wide band readings.

Lance.

This is an old thread, but what the heck. First, after getting my MS2 tuned, I seldom had O2 correction of more than 1 or 2 %. So once set up, (correctly!) you really don't need it. A friend of mine is a tech at Ford racing, and he tells me the O2 sensor on a Ford provides 3% of the information for closed loop operation.
So far as not tuning with an O2 sensor at all, sure it can be done, and I am sure you can get the car to run well enough to drive and be happy. But if you are looking to get top performance there is no way that is enough. There is too much to play with on an EFI car. With carbs, you cannot get ideal fuel everywhere. You can get it in a narrow window. So in a race car, which typically runs in a 2000 RPM window, you can read plugs and get where you want to be, pretty much. I will point out that race cars today have wide band O2's on each cylinder, after each pass you read the plugs AND read the data log. There is an old saying and it is true "Torque rich HP lean" Hard to hit that without reading an O2. Maybe your car will produce a few more Ft Lbs of torque at peak torque (let's say that is 3,500 RPM pure street motor), at 12.0 AFR than it does at 12.5 AFR. And maybe you get 4 or 5 more HP at 13.5 AFR than you do at 13 AFR. Reading plugs will not get you that close, time slips and data logs will. I also use a G Tech Comp Pro for tuning. It is a 3 axis accelerometer. You can't tune by "feel" Perfect example here, in the early days of NHRA Pro Stock, Dick Arons and Wally Booth started playing with cam timing. Wally made a pass and he said when he shifted it felt like he was hit by a freight train! He was so excited at the end of the run he shouts to Dick "How much faster did it go???" Dick shouted back "It slowed down 2 hundredths!" No power was added, they hurt top end power so when normal bottom end power came in it FELT like more. It is easy to be fooled by "feel" so you need documented and measureable data by which to tune if you are looking to get the most out of your equipment. If you just want to drive the car, and have fun, and enjoy yourself, well then if it feels fine to you that is all that matters.
Tom