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WB O2 controller necessary with MSII?
Posted: Sat Nov 14, 2009 6:41 am
by lemans70sport
After reading the manual several times and researching posts in the forums, I'm still confused over the need for a wide band controller. I have an Innovate LC-1 that has stopped communicating and am wondering if I needed it in the first place. I'm running E85 and haven't got past getting the engine to idle yet.
Re: WB O2 controller necessary with MSII?
Posted: Sat Nov 14, 2009 1:02 pm
by Bernard Fife
lm70sprt,
You don't *need* it, that is MegaSquirt will work without it. How comfortable you will be without one depends mostly on how much tuning knowledge and experience you have. Remember that in the old days (before about 10 years ago), NOBODY used a wide band sensor, and yet some very high horsepower engines were successfully tuned and run hard without burning up.
I never use a wide band for tuning (for a number of reasons). However, I do like having one on the car to let me know if anything in the fuel system is changing (and thus needs fixing).
People who haven't tuned much often like to have a wide band to get them 'in the ball park'. That's fine, but they should be aware of the limitations:
- the wide band isn't as accurate or fast as many companies claim, and
- if you don't have a lot of tuning experience, you don't necessarily know what AFR to tune for anyhow. There are rules of thumb for this, but they are unlikely to be the optimum values for *your* particular engine.
Lance.
Re: WB O2 controller necessary with MSII?
Posted: Tue Nov 17, 2009 4:08 pm
by lemans70sport
Lance,
Thanks for the reply but I didn't phrase my question properly. I still want to use my wide band O2 sensor and am wondering if I can wire it directly to MSII without going through a controller. Can I still see my Air/fuel ratio when tuning?
Re: WB O2 controller necessary with MSII?
Posted: Tue Nov 17, 2009 4:31 pm
by trakkies
lemans70sport wrote:Lance,
Thanks for the reply but I didn't phrase my question properly. I still want to use my wide band O2 sensor and am wondering if I can wire it directly to MSII without going through a controller. Can I still see my Air/fuel ratio when tuning?
Don't think a wideband sensor will work direct with an MSII. They work on a different principle from a narrowband one.
Re: WB O2 controller necessary with MSII?
Posted: Tue Nov 17, 2009 5:05 pm
by Bernard Fife
lemans70sport,
Dave is right, you must have a controller. The WB controller is 'active' (feeding a current to balance different parts of the WB sensor - the AFR is related to the current required. A narrow band sensor is passive (it sends a signal without any electronics). For more info on how a wide band controller works, see:
http://www.megamanual.com/PWC/LSU4.htm
Lance.
Re: WB O2 controller necessary with MSII?
Posted: Wed Nov 18, 2009 3:17 am
by lemans70sport
Got it. Thanks for the replies.