Wideband sensor on MS1

[zoltan]

How have people connected their wideband sensors into Megasquirt?

I have been using a stand alone LC1 lambda reader with the 5 wire Bosch sensor and am getting a variation between the stand alone reader (LC1) and the Megasquirt ECU in Megatune. Megasquirt is running about 2 points richer generally.

I've used the figures from the LC1 and ignored Megasquirt. Now I'd like to just run the Bosch sensor straight into the ECU now as I can't always have the LC1 (belongs to work)

I have been using the analogue output from the LC1 into Megasquirt, could this be where my problem lies?

I realise this is a bit of a non question but am interested to hear other views and opinions

[Quagmire]

Are the squirt and the LC1 powered and earthed from the same locations?

Sounds like you have some kind of voltage offset causing the difference in readings, I had the same thing with my Megajolt until I redid some of my wiring to bring both +ves and earths to the same locations. Even then I had a difference, although it was small.

As for connecting the wideband sensor directly into squirt, this can't be done as you need the LC1 (or similar) to actually drive the sensor.

*edit- from what I've read using the analogue output is the correct way to do things, just make sure you have the output range on the LC1 matching what the MS is expecting to see.

[zoltan]

The LC1 and Megasquirt had to be powered and earth separately as the LC1 comes out of the lighter socket 12v supply. I might make up another lead and see if taking the same location makes a difference.

Was there some wideband project going on for Megasquirt or did I just dream it?

[FridgeFreezer]

There is a DIY-WB project but it never seemed to gain much over just buying an LC-1.

You need to ground the signal return wire from the LC-1 to the ECU connector ground, the power supply to the module can still be from the cig socket.

[zoltan]

Are the issues to get Megasquirt to read from a wideband such a big deal electrically? Does it not see it as another sensor with an 0-5v output range or is there much more going on? It accepts 0-1v from a narrow band happily enough or is it just one of the drawbacks of having version one of Megasquirt and learn to live with it?

[Bowie69]

You can configure MS1 to run qith a wideband 0-5V 10-20:1 AFR and many other options, it's all in Megatune if you look closely enough.

[zoltan]

You can configure MS1 to run qith a wideband 0-5V 10-20:1 AFR and many other options, it's all in Megatune if you look closely enough.

Thanks, Ive forgotten too much and reached a high level of befuddlement with Megasquirt since getting my 110 running last year. Much of it probably centred around the voltage/reading difference issue with the LC1. Need to reacquaint myself with it again

[Hybrid_From_Hell]

As a matter of record Mr Bul Bar Cowboy tuned his 3.9 V8 with a Narrow Band and MLV,

with some logs done and some human input he gained a hugely smooth and powerful V8.

He then went to a 4wd Rolling troad, and wide band, the work he had done with NB + MLV wa

so dmaned good the rolling road owner was stunned and said that time on the rolling road

would be a waste of money

so good was what Ian had reached. Megasquirt is as simple - or as compciated as you wnat to

make it - you do NOT need fancy and expensive WB Lamdas to get a seriously good map,

NB & MLV (or tuner studio) takes the hard work away with the algorithmic calcs done for you

At the end of the day, the lovely Rover V8, whatever version, ir only a decendant of a 50's buick engine

and its not going to be a track day car where every single 0.5BHP Counts

Just a thought ? ..

Nige

[mad_pete]

how does narrowband handle the richer AFR targets on full throttle ? Does the code tune to 14.7 is and then add in a bit more fuel based on engine size ?

[Bowie69]

It tunes to an AFR table setup in either Tuner studio MS or Megalogviewer, or in the case of a wideband sensor, setup in Megatune or Tunerstudio.

This is all in the 'uber' MS thread somewhere...

Narrow:

http://forums.lr4x4.com/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=4961

Some notes on Wideband:

http://forums.lr4x4.com/index.php?showtopic=15317&st=40&p=170059entry170059

See Tunerstudio MS help files for how to do it in there.

[zoltan]

As a matter of record Mr Bul Bar Cowboy tuned his 3.9 V8 with a Narrow Band and MLV,

with some logs done and some human input he gained a hugely smooth and powerful V8.

He then went to a 4wd Rolling troad, and wide band, the work he had done with NB + MLV wa

so dmaned good the rolling road owner was stunned and said that time on the rolling road

would be a waste of money

so good was what Ian had reached. Megasquirt is as simple - or as compciated as you wnat to

make it - you do NOT need fancy and expensive WB Lamdas to get a seriously good map,

NB & MLV (or tuner studio) takes the hard work away with the algorithmic calcs done for you

At the end of the day, the lovely Rover V8, whatever version, ir only a decendant of a 50's buick engine

and its not going to be a track day car where every single 0.5BHP Counts

Just a thought ? ..

Nige

I agree that you don't *need* a wideband sensor to tune but is a great deal easier when you can see the whole spectrum instead of one small portion of it. With petrol at £1.40 a litre I don't want to be wasting very many drops running richer than necessary to achieve a map.

We had no lambda reader on our dyno in the early 90's and the Horiba gas analyser was so slow to respond that you'd need to hold the engine for at least 20 seconds to get a mixture reading. Scary when making full power runs. We managed but once you've sampled the nectar of a simpler faster tool its hard going backwards

[FridgeFreezer]

Zoltan - as per Nige's example, you really are chasing diminishing returns. I'm not saying it's not worth it, but it's orders of magnitude; going from carb or open-loop EFI to narrowband-tuned takes you from the sort of +/-10% at very best kind of range to +/-1% sort of ballpark on the fuel map if you analyse what MSTweak etc. are doing and the adjustments you're making. Going to wideband you're tuning out the last couple of % error in the fuelling, plus/minus the error in the wideband due to response curve etc. and of course the barn-door error margin that is the big clunky Land Rover it's all bolted to.

If you look at how MSTweak works, it's using the NB numbers and adjusting to calculate AFR's you'd see with a WB, and it does pretty damn well.

I still think you need to make sure the signal & return lines from the LC1 are direct to the MS, it was always an issue back in the early days.

In short - it's nice to do WBO2 tuning, but not worth getting stressed about.

[zoltan]

I clearly haven't been using the auto tune method allied to an AFR table for sorting my fuelling which is why Ive been wedded to the LC1 and WB sensor and probably making life harder for myself. This is the old school type mapping you have to do with other systems

I probably need to be more trusting of the new fangled tools available in the ECU

[FridgeFreezer]

The on-the-fly auto-tune in MegaTune is OK but basic & not infallible, I usually do data logging followed by MSTWeak3000 which analyzes the data & adjusts your fuel map towards a target AFR table, it's very good but does tend to get the idle zone wrong (I just tweak it back by hand). I understand TunerStudio is very clever but I've not played with it.

Remember all of these rely on the reading from your O2 sensor being good, so exhaust leaks etc. can throw it out - as with all software, rubbish data in, rubbish result out!