Megasquirt: Do I need a wideband O2 controller?: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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May 5, 2009 9:42 a.m. walterj Dork

I am doing my 1st megasquirt on an E30... and this is probably a really dumb question but it had been my understanding that all I needed to do was install the wideband in the bung, power it and wire the signal right to the megasquirt and it could use it directly...

Am I missing something? Why does every megasquirt writeup have instructions for installing a wideband o2 controller? Does it need additional signal processing to interface to the squirt or is it just for monitioring the fuel mixture with a gauge (sans a laptop)?

(BTW, the o2 I have is a Bosch 5 wire that DIY sells as a replacement for the LM setup)
May 5, 2009 9:52 a.m. Taiden New Reader

I have never built a megasquirt, I have only done research.

As far as I know, you need a wideband controller to do a few things

1) facilitate sensor warm up 2) provide voltage to the sensor. 3) provide a clean, linear 0-5v output for AFR

If you want cheap, check out JAW (just another wideband). He has a controller that fits in a tictac box for something ridiculously cheap like $30.
May 5, 2009 10:02 a.m. Xceler8x Dork

My Lc-1 came with a controller unit that lives under the car. Without that unit the wideband won't work.

Also, the wiring scheme corn-fused me for a bit. The multiple grounds was a bit weird. Make sure you're grounding it right or it won't work well.
May 5, 2009 10:03 a.m. alfadriver Reader

Correct, WB sensors need a lot more than just checking the voltage- they have unique circuitry to run them, as Taiden has mentioned.

One of the most missed aspects of WB sensors. It would be cool if someone made a daugherboard for the MS, though.

E-
May 5, 2009 10:09 a.m. Dr. Hess SuperDork

If you have a wideband O2 sensor, you need the controller, as mentioned. The real question should be: Do I need a wideband O2 sensor? I have 3 MS'ed vehicles with narrow bands, one an unheated 2 wire to save the amps. On a non-boosted motor, I think a narrow band is fine. Sure, a wide band would make tuning a lot easier/faster, but the cost is way up too.
May 5, 2009 10:29 a.m. walterj Dork

Dr. Hess wrote:

If you have a wideband O2 sensor, you need the controller, as mentioned. The real question should be: Do I need a wideband O2 sensor? I have 3 MS'ed vehicles with narrow bands, one an unheated 2 wire to save the amps. On a non-boosted motor, I think a narrow band is fine. Sure, a wide band would make tuning a lot easier/faster, but the cost is way up too.

I did think about this - its a racecar and so probably does not need an O2 at all once it is dumping a decent mix at WOT but I have never done my own engine management. I figured it would reduce the guesswork and make it a little easier by having better feedback to post when it didn't run right. That is worth the extra cost in edumacation value... but this is a leaning exercise so I really don't know if that is true. I'm cool with the $ if it really is helpful to the "next" project in acquired knowledge.
May 5, 2009 10:42 a.m. Paul_VR6 Reader

If you only care about WOT and you're just going to tune it on the dyno for max power and never adjust it again, you probably don't need one. If you ever plan to monitor things, or change it from the dyno tune, having it is invaluable.
May 5, 2009 10:55 a.m. njansenv Reader

I've done MS both ways, on a number of projects ranging from a Briggs and Stratton to a 2.4turbo neon. The wideband followed each project, and was unbelievably useful once I ponied up for it. It makes tuning much, MUCH easier, but people have been tuning without WB's for years. :)
May 5, 2009 11:05 a.m. ditchdigger Reader

In my opinion you either cough up the $199 for the innovate LC-1 or you pay for dyno time. In my case counting in travel costs to get 120miles to the nearest dyno, paying for said dyno runs and then a meal and a return trip the LC-1 was the cheaper option. Plus whenever I change anything with the car all I need is a spirited drive with a laptop to datalog and I can retune myself.
May 5, 2009 11:14 a.m. walterj Dork

ditchdigger wrote:

In my opinion you either cough up the $199 for the innovate LC-1 or you pay for dyno time.

I just ordered this... http://14point7.com/Widebands/NAW_OEM/NAW_OEM.htm

Based on the guy's previous good track record building these things and the low entry cost I could not resist the temptation - and I will install it using an actual tic-tac box.
May 5, 2009 2:07 p.m. Raze Reader

We dove right in w/a wideband for our MS build and it was worth every penny spent. Do some reading up if you decide to get one on the different types out there, we stayed away from Innovative Motorsports LC-1 because of the need for re-calibration (not bad but still annoying), it's lower max bung temp threshold, and almost everyone we'd run across who had or were using an LC had at least one go bad on them. 3 years later and ridiculous amounts of abuse during initial engine running to full on tuning going full lean to full rich with vacuum leaks leading to excessive EGTs on up to 30psi dialed in pulls and the PLX is solid as a rock, and works same as when we got it.

So what sensor are you going to use with that?
May 5, 2009 2:34 p.m. walterj Dork

Raze wrote: So what sensor are you going to use with that?

Bosch LSU 4.2 sensor. Part # is 17053.

I'll report back for posterity... it will take me a while to get everything wired up - I'm still running off the Motronic right now while I research and get all the parts to convert it piled up and ready to go.
May 5, 2009 5:49 p.m. Taiden New Reader

walterj wrote:

ditchdigger wrote:

In my opinion you either cough up the $199 for the innovate LC-1 or you pay for dyno time.

I just ordered this... http://14point7.com/Widebands/NAW_OEM/NAW_OEM.htm

Based on the guy's previous good track record building these things and the low entry cost I could not resist the temptation - and I will install it using an actual tic-tac box.

Yes, this is the exact wideband I mentioned. JAW's wonderful fit-insite-a-tic-tac-box-WB-controller. $55 + the O2 sensor. Fantastic.

He also makes a larger one that can be purchased without any sort of display for $25. http://14point7.com/Widebands/JAW_1_041/JAW_1_041.htm
May 5, 2009 6:10 p.m. walterj Dork

Taiden wrote:

Yes, this is the exact wideband I mentioned. JAW's wonderful fit-insite-a-tic-tac-box-WB-controller. $55 + the O2 sensor. Fantastic.

He also makes a larger one that can be purchased without any sort of display for $25. http://14point7.com/Widebands/JAW_1_041/JAW_1_041.htm

I had a really hard time locating his site... all the links that everyone was using from a year ago are dead and google doesn't know about him at all. I stumbled on it by luck reading a recent e30tech post that had a working link to the 041 version and worked around from there. I will drop him an email letting him know... he needs some indexing.
May 5, 2009 7:23 p.m. fifty New Reader

I thought the JAW guy was taking people's money and not shipping product. Has that changed?

Check out www.wbo2.com also - they have an excellent DIY kit for about $100 Australian (~$70 - $75 US dollars): http://www.wbo2.com/2y/default.htm