Need advice from the experts about a wideband
 

Hey guys, I'm at the point where I need a wideband and wanted to know what some of the experts that have used/tuned with widebands think about the DIY deal floating around the forum. I love the idea of getting a good, reliable, accurate wideband built with a sensor for $300 but is it really accurate and fast enough to tune with? Do you guys think its good enought for me to bet my engine on? In terms of accuracy and speed is there any reason it shouldnt be as good as the expensive widebands???

Are there some featurs I would be missing out on by going the DIY route versus a Motec or FJO??? I dont have to worry about dataloging cause I can plug the DIY kit right into my PFC datalogit.

I have to get a wideband and just want to make sure if I spend $300 on this one its not going to be a waist of money.

You think a few of you experts like Chrispees, RiceRacing, ect.... could chime in a give a guy some advice.

If you dont know what I'm talking about here is a link..... http://www.techedge.com.au/vehicle/wbo2/default.htm

Thanks,
STEPHEN

I have the MRM unit and I am happy with that. Good interface and easy to use. A local guy bought one of the DIY pre-assembled kits, just waiting on delivery. We are both curious how it compares.

I am not sure if anyone has compared two units side by side.

Go here and it'll answer your questions: http://www.motec.com/products/plm.htm
I got mine and just can't wait to get AEM's ems. It'll be wicked with both units.

If I remember correctly the only problem with the diy wideband over a motec or mrm is that it doesn't compensate for temperature, which can lead to some problems when your putting out lots of heat trying to tune the top end of your maps.

I'm at the same point of trying to decide which one to buy, I like the cost/ simplicity of the DIY but the MRM is looking better at the moment. Like styk33 said I'm still waiting for a side to side comparison of the 2.

Matt

Well I have been busting my balls over this one for a while now !

I too think the PLM from motec is a kick ass piece of gear for the cost with LSU sensor, though general thought is that it is not as good as the NTK (Eugo) sensor, this can be used with the PLM if you need to change it at a later date as it will work with all sensors.

NOW, Autronic make two models, the one that compares to the PLM in quality (actually better) is the B Model, it runs a Eugo NTK sensor and is the best unit in terms of accuracy, the problem is the COST $2500Aus without the sensor !

BUT, I have found out that Autronic are releasing a new model that will be the same price as the motec $1880Aus + it will have an RPM input with logging ability so you can just plug it into your laptop and do logging like the MRM unit wich Jay has THIS WILL BE THE BEST UNIT, but not sure on when it is coming out cause Autronic are a bunch of ass holes and will not release the date !

Now MRM no longer will be doing the M&W Ignitions unit, they buy it from Australia and modify it, you can buy a M&W Ignitions one, but they are VERY expensive, the base kit start at $2500Aus, but it's performance I believe is as good as the Autronic B Model analyser as it uses the NTK sensor + it allows logging as std, the only problem is that for $2500 you get no display ! you need a lap top or a pocket PC !

Then there is the FJO from Canada, it is maybe the best in terms of value for money, it has the NTK sensor, it has rpm input, it has MAP pressure input, it has display, it does logging, all for around $2300Aus I think? I am just unsure cause I have not herd much of the company, but the guy used to make stuff for military contracts so I say it would be up there in quality ?

SO, choices choices ? Me I think I will wait for the NEW Autronic range because they can be interfaced with my ECU and allow AUTO TUNNING, where you simply enter in the a/f ratio you desire accross your fuel map points from idle to redline from vacume to full boost and the ECU will program its self ! In real time with NO RISK of running LEAN. THIS ALONE IS A TOP FEATURE but you need an Autronic ECU to use this. They will be making a cheaper wideband interface that will cost around $500Aus that will do the same job, but will not have a display.

Enough options for you? :)

If I wanted a gauge right now and did not want auto tune, I would pick the motec PLM if I wanted a name brand that is realy good. If i wanted the most features and best price I would pick the FJO as it does logging via 2 additional inputs. Autronic at the moment are too expensive so count them out till the new models come out.

Hmmm, well that clears things up as much as mud!!!! hehe now I have waayyy too much info, I'm worse off than before hehe

Well, the PFC datalogit software is designed to interface with the DIY wideband kit. As my datalogit is logging by rpm it will show the a/f ratio along with all the other info next to each rpm range.

All I need to know is if I can trust the a/f ratio of the DIY or not, I dont really need the fancy features. I'm just looking for a good solid a/f ratio that I can trust.

Will the DIY provide that as far as you guys can tell?

What's the deal with temperature compensation? Is this a subject to worry about with the DIY???

Thanks,
STEPHEN

The guy who make the DIY lives up the road from me!

He assures me that it is accurate, and the NTK sensor is self correcting, I got the same info from an Autronic reseller who told me the same thing about the NTK sensor.....

I think wait for Jays back to back result compared to the MRM (M&W) unit to make it 100% sure :)

I am a bit like you in that I do not mind paying a bit more for a proven item that LOTS of people have used.

I just bought the DIY fully assembled WB with the display, and all the cables you can get. It was around $250 I think. Add $115 for the NTK sensor from thepartsbin.com. The motec is around $1K with the bosch sensor...HELLO??? The whole point to the DIY project was to find a reliable, cost effective WB monitor. Read the original DIY project info, not the stuff at techedge if it makes you feel better. This was just a group of guys that put their heads together to come up with a common solution, and not mark it up 300% in the name of making a buck! I think we all put so much cash into our cars that we think if it doesn't cost a fortune it's not worth it. Bullsh*t!

The datalogit allows you to enter the coefficients for a polynomial (2nd order ax^2 + bx + c) to adapt the reading to whatever the input is. Of course, this may not be sufficient depending on the output voltage versus A/F ratio for all wideband units, but you can probably get a graph of the output voltage versus A/F ratio and figure out what coefficients to enter. And with a wideband unit that has a display, you can probably just measure the output voltage while you adjust your A/F ratio at idle to produce your own graph if you need to.

I entered the data values for the DIY wideband kit into Excel, graphed them, and then right-clicked on the line to add a Trendline. With a 2nd order poly, I wasn't able to get a good fit for the whole thing, but when I chopped the series down to the 10-15 A/F ratio range, the fit was excellent. This just means that the logged A/F ratio will only be accurate in the 10:1 to 15:1 range, but that is perfectly fine for tuning. The values are:

a: 1.3874
b: 1.2575
c: 9.135

The equation, where x is input voltage turns out to be:

A/F Ratio = 1.3874x^2 + 1.2575x + 9.135

I attached the chart showing the original data and the tendline:

Max,

What you have experienced is basically what the M&W guys take care of for those that are willing to pay for it. They package their wideband kit with a logic unit that converts the NTK sensor output into a linear relationship of voltage and AFR. 0 volts = 10 AFR; 5 volts = 20 AFR, linear inbetween. IT works very well but it costs about $1000-1200.

Kyle

I should point out that I don't have a wideband (yet), but rather I was just curious what it would take to datalog its output accurately.

-Max

I'm very very very biased towards the M&W Eugo unit!:)
One thing I've noticed is that the Bosch sensor cannot even come close to the accuracy and speed of the NTK unit. The Bosch sensors are also not tolerant of leaded fuels for extended periods and are very prone to damage from moisture. In comparison after three years of use from the NTK sensor we've already lost about 20 Bosch sensors!:(
Plus the M&W unit can display A/F ratio for petrol, propane and alcohol. I'll be testing it with alcohol fuel shortly for the first time. I'm using my car as the guinea pig!:) Can't wait for the results.

crispeed
87 Rx-7 TII
9.204@150.47mph
2600lbs