Megasquirt Support Forum (MSEXTRA)

I see an old thread in 2012 about this, but nothing since then.

For those of us wanting to monitor O2 before the turbo, this would save us buying an external unit to do the compensation for us.

Was wondering if this is planned or somehow managed already?

The O2 compensation has to be done by the WBO2 controller because that is dependent on the Nernst cell current inside the sensor. This is not visible externally so it cannot be done in the MS3.

So you need a controller that supports this. The MegaSpartan from 14point7 does support it and is designed for easy integration with the MS3. There are likely others but I'm not familiar with them.

Jean

thanks. I'll look into Alan's solution -- he says the backpressure stuff isn't done yet, but in a couple months the new firmware will be out.

The AEM 4-channel CANBUS unit uses the LSU 4.2 sensor. A rep said using the LSU 4.9 sensor is "on the horizon" -- whatever that means.

thedrew wrote:thanks. I'll look into Alan's solution -- he says the backpressure stuff isn't done yet, but in a couple months the new firmware will be out.

The AEM 4-channel CANBUS unit uses the LSU 4.2 sensor. A rep said using the LSU 4.9 sensor is "on the horizon" -- whatever that means.

Have you heard from him on this recently?

yeah, i emailed him about it this week and got this:

The pressure compensation feature is still being worked on, a new firmware will be released in about 2 months. The firmware is end user updateable.

I will carry and sell the pressure sensor once the new firmware is released.

Good to know. I have firmware in mine right now that is supposedly doing the comp stuff. I sent some datalogs to him early this week, hopefully he can do good things with what I gave him, cuz my car is done for the season, requiring some pretty major TLC.

Yeah, I'm about ready to pull the trigger on the megaspartan -- my cars done till the spring, so I hope the firmware is done by then.

I can't decide if I want the 5 channel (to pick up the average) or is the 4 channel all I'll ever need.

I use the 4, with an outside 5th till i trust the device. The computer creates an average and uses it to tune your ve table with. Running a 5th will be difficult to do and not confuse the computer. I currently run my 5th as a generic sensor, i feed it direct to the IOX over serial, then i convert that signal to a 0-5v and use an ADC from the IOX to the MS3 as such. I then just input the Innovate calibration data and created a gauge. That way it doesn't have any affect on the tune. It responds later than the per cylinder devices do, so it definitely made tuning tricky back when i had it listed as a 5th ego.

chips60bug wrote:I use the 4, with an outside 5th till i trust the device. The computer creates an average and uses it to tune your ve table with. Running a 5th will be difficult to do and not confuse the computer. I currently run my 5th as a generic sensor, i feed it direct to the IOX over serial, then i convert that signal to a 0-5v and use an ADC from the IOX to the MS3 as such. I then just input the Innovate calibration data and created a gauge. That way it doesn't have any affect on the tune. It responds later than the per cylinder devices do, so it definitely made tuning tricky back when i had it listed as a 5th ego.

good to know, thanks!

I found this info on the LSU type sensors. Maybe this info could kick off the implementation of this feature request.

Last page has temp/pressure curves

racingmini_mtl wrote:The O2 compensation has to be done by the WBO2 controller because that is dependent on the Nernst cell current inside the sensor. This is not visible externally so it cannot be done in the MS3.

So you need a controller that supports this. The MegaSpartan from 14point7 does support it and is designed for easy integration with the MS3. There are likely others but I'm not familiar with them.

Jean

Are you saying the Megaspartan has compensation based on pressure as a feature? That would be amazing, but I just checked the documentation on it and can't find any reference to backpressure compensation. Temperature control, yes...compensation for pressure, not that I can find....yet?

I emailed them, its coming in spring they said. Looks like a firmware flash more then hardware from what i gathered.

93supercoupe wrote:I emailed them, its coming in spring they said. Looks like a firmware flash more then hardware from what i gathered.

technically could probably grab the data needed for that off the MS CAN BUS. REALLY looking forward to this product.