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DIY Wideband for Bosch LSU4


Nigel

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Does anyone know of a cheap DIY wideband controller for the Bosch LSU4 wideband O2 sensor? You can get these sensors super cheap ($50US and less!). I'd like to get something up and running quick for under $100US. I'm familiar with http://www.diy-wb.com/ and http://www.techedge.com.au but diy-wb.com only talks about the more expensive NTK sensor, and techedge wants around $130 just for the kit (admitedly a nice one though).

 

Any suggestions?

 

Nigel

'73 240ZT

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Check with TechEdge again. I belive the new WB V2.0 unit can use the LSU4 and an even cheaper VW version of the sensor. WB is not going to be had for $100. Stop dreaming. :wink: Keep in mind that most WB units go for $500 and up.

 

I'm using the V1.5 unit with the NTK sensor and love it. At least you're looking at using a WB O2 sensor. Most try to use a NB sensor. Narrow Band sensor based A/F meters are complete junk for tuning purposes. Wide band with an EGT is the only way to go. It always amazes me that people with spend huge bucks on an engine and them scrimp pennies on the setup and tuning. To me that is the ultimate RICER trick. If it doesn't LOOK PRETTY then don't spend the bucks. :lol:

 

Keep in mind that once you're done with the tuning, you can always sell the WB meter on eBay and recoup most, if not all, of the cost.

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I don't think sub $100 diy wb is that unreasonable anymore. The diy-wb.com kit for use with the ntk sensor is only $18! If it worked with the bosch sensor, then that would come out to $80 or $90 with shipping. I'm familiar with the innovativemotorsports.com unit as well. $130 for the techedge 2.0 kit is an awesome price for what you get, but that would be closer to $200 with the sensor. And I'm in Canada, so the price for me would be closer to $300.

 

Come spring, I wont mind spending that kind of money, but I've been spending pretty hard this year. However, if I could put something together cheap before the trip to the convention in October, then I'd do it.

 

I have a nb gauge in the car right now. I'm very familiar with the limitations of nb (rich, lean or somewhere in the middle, and that's it), but at least it's kept me out of trouble. At the time I got the car running, wb was just not an option. I'd have been looking at $800+ CDN. My engine builder has an fjo wb meter, and I did some tuning with that recently. Without question, wb is the way to go.

 

Nigel

'73 240ZT

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Guest bastaad525

I gotta say... a lot of people are running N/B sensors and gauges, not all ricers... doesn't make sense for them to be completely useless. How can they be so innacurate? I mean how many FI cars use a NB sensor to help their ECU's fine tune the fuel mixture? Like... all of them? If it's good enough for the ECU, why not good enough for the driver? If they really only read rich/lean/somewhere in the middle, isn't that all you need? I dont know about you but I'd just shoot for 'somewhere in the middle' and be done with it! So are you telling me that if a NB sensor reads right in the middle, stoich, that it's still not accurate? That makes me think a lot of cars should be running a lot crappier than they do....

 

Like Nigel says... I'd want an NB sensor mostly just to keep me out of trouble... in other words... in my turbo car it's of the utmost importance that I dont run lean since that can very quickly kill my engine.

 

Now what I want to know, is CAN an NB sensor give me enough information for me to keep my car from running lean, or NOT?

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The problem with the NB sensor is that you cannot see the difference between say 14.0 to 12.0 very well. They are both on the rich side of stoichiometeric. But for your turbo 14.0 is probably not rich enough. It is very difficult to measure stoichiometric with a NB sensor (almost impossible). It can only measure rich or lean. Modern ECU's sort of average the lean/rich time to determine stoichiometric. So in answer to your question. Yes a NB-sensor can measure wether you are running richer or leaner than stoichiometric, BUT (this is important) It cannot tell you if you are rich enough. In other words I would not rely on a narowband sensor for my turbo in it's power band.

 

I hope this all makes sense since English is not my native tongue. I't is a close second though. I read a lot of english books but writing is a whole different story,

 

Xander

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Guest bastaad525

Perfectly understandable dude I'd never know you weren't a native english speaker. You just cleared up one major point for me that I was not aware of, that you want a turbo to run richer than stoich. I always thought that no matter what the application stoich is what you aimed for, for maximum power and reliability. So I can see how a NB sensor would be useless for a turbo car... ah well...

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Just to elaborate a bit on what Xander was saying, stoichiometric (14.7:1 AFR) is the ideal for low HC and CO emissions, but best fuel economy is slightly leaner than that, and best power, somewhat richer. Factory ECUs run off the O2 sensor at idle and cruise for best emissions since this this where the output of the O2 sensor is most meaningful (averaging at stoich by bouncing between rich and lean as Xander stated). But at full throttle, they switch to a pre-programmed fuel map because the output of the O2 sensor doesn't provide a very meaningful output in the rich range (or the lean range for that matter). Like Xander was saying, you could be running 12:1 or 14:1 and not really be able to tell the difference from a nb sensor.

 

I found that I was running too rich when I tried out the wb sensor. My readings were in the 10:1 range at full throttle! Better than being too lean, but still pretty far off the mark. This is where the wideband sensor is critical.

 

Incidently, the new Dodge turbo 4 cylinder (found in the Neon and PT Cruiser) is designed to run at full throttle at Stoichiometric!

 

Nigel

'73 240ZT

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Guest bastaad525

I"m curious... if the ECU just switches to a preset curve at full throttle and doesn't rely on the o2 to tell if it's running rich or lean, how does the stock nissan ECU know, or compensate for, increased boost? If the airflow meter is maxed out after 4000rpm at full throttle, it's not taking any measurement there. As far as I know the stock ECU has no way of actually measuring boost right? How can the ECU compensate if the two main parts that tell it how much air is being mixed in with the fuel aren't doing anything? I would think this would limit the stock ECU to the stock boost setting..... not trying to be argumentative I"m really just very curious how this works!

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I'm not all that familiar with the ZXT ECU, but a lot of factory fuel maps are pretty conservative (ie, pretty rich at full throttle). So, you can get away with a few extra pounds of boost. But you're not going to be finding anyone running 15#'s of boost on a completely stock ZXT fuel system. Probably beyond 9 or 10#'s you're looking at tweeking the air flow meter, adding a rising rate fuel pressure regulator, or adding some additional injectors and a separate controller to meet the increased fuel demands. But, as for the ECU, it still thinks you're only running stock boost.

 

Nigel

'73 240ZT

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Guest bastaad525

Someone should write the guys at diy-wb.com and let them know about the cheap Bosch sensor and beg them to make a version of their diy that works with that... I also think it's no unreasonable to want a WB setup for around $100... $500 is rediculous. Even $349... it just seems cheap because of all the high priced competition... and maybe it is a good deal for what it does but I could just go spend $75 at a dyno for three pulls and tune the car that way and as a 'bonus' I get a full readout of the what the car is doing and hp and torque and stuff... It's hard for me to say $350 is reasonable at that point, considering usually once you've tuned at the dyno once you dont really need to tune again unless you make major changes.

 

I'll hold out I think it's only a matter of a very short amount of time before someone makes a cheap unit or a diy unit that will work with the Bosch sensor...

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  • 4 weeks later...

I agree, wideband is the only way to go....

 

http://www.innovatemotorsports.com/ - $350, if I had he extra cash right now this is how I could go. You have to take into account that this is more than just a basic WB kit. With all the extra IO, the ability to data-log (VERY NICE), RPM input...and being able to run things like EGT meters too, it becomes a very good deal. Plus, it will emulate a NB sensor for connection to the ECU.

 

Personally, right now, I think I'm going to be going with the tech edge ver 2. With cable, should be about $150 shipped, plus under $50 for the sensor putting the total under $200.

 

I do think the diy-wb guys would be good to modify their units to allow the use of a bosch sensor, but I feel that there is probably a reason they haven't. I recall reading a reason, like it was harder to interface to or something like that.

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The Innovative Motorsports meter is nice, but if you want auxilliary inputs, then you have to purchase one of their input cable. The basic 6 input cable is only 25 dollars, but if you want RPM input then the price jumps to $99, and for RPM, thermocouple and map input it jumps to $199! So, now you're looking at $450 for diy with rpm input vs ~$150 (+ sensor) for the techedge with rpm input and datalogging.

 

Nigel

'73 240ZT

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