Dual Widebands Stock Locations

[donniekak]

I think I recall something similar, he was running them really close to the turbo IIRC. Could have been killed by the heat, maybe leaded fuel, over rich, not sure.

It's worth the $110 for the sensors to try to me. If I kill them oh well, but would suck to setup the wiring neatly and careful and have it not work out. Was hoping more folks had tried this, I guess not a lot of people don't use the narrowbands.

$110? I get my wideband sensors at autozone for $70ish.

Lots of Dsm guys use wide bands in the o2 housing. The makers of dsmlink recommend this placement. The software in link lets the stock ecu use the wideband for trimming, and let's you log the wideband with the rest of the ecu data. Oh yeah, native speed density on the stock ecu as well.

[Chris@Rvengeperformance]

$110? I get my wideband sensors at autozone for $70ish.

Lots of Dsm guys use wide bands in the o2 housing. The makers of dsmlink recommend this placement. The software in link lets the stock ecu use the wideband for trimming, and let's you log the wideband with the rest of the ecu data. Oh yeah, native speed density on the stock ecu as well.

Yeah I meant for 2, they are $54 right now on amazon.

That is good to know, I think I will make the switch. Do you see any issues running a lsu 4.2 sensor in one bank and a 4.9 in another? Otherwise I'll just have to sell my current wideband.

[Chris@Rvengeperformance]

FYI: http://www.bosch-motorsport.com/medi...9147659pdf.pdf

Rated for 930c continuous, 1030c max intermittent. o2 housing should not see that temp unless you have some issues.

I received one of the 30-4110 in the mail today and I'm going to run that in the front and the older lsu 4.2 in the rear bank for now until I upgrade it. It should be interesting to compare the response times in logs.

[murphys_law]

The 4.9 is where it's at. No free air calibration required!


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[R/T93]

Those look like the ticket then. No they won't see those temps no way.

[KeithMac]

I fancy 4.9's but I'd have to start from scratch with another controller..

The 4.2's main issue was sampling under bonnet air as fresh air, if you have no exhaust or oil leaks it shouldn't be an issue.

[futurevr4man]

Watching with bated breath...

[Chris@Rvengeperformance]

The more I read the less actual difference I see between lsu 4.2 and 4.9. The 4.9 was designed to report leaner mixtures originally to support diesels. Bosch changed everything over to it because it worked fine for gas. It has a smaller ceramic heater part, so it can light off quickly and reduce cold start emissions. It should be slightly faster due to less thermal mas.

Either should work about the same in practice though and the controller can have more impact than the sensor differences. The new X-series aem widebands have about a 20ms response time and the older controller types (including the 30-4110 I received) do about 50-60ms.

Based on my datalogs the car doesn't really sweep through that much rpm in 60ms, so I am not sure there is a practical difference. There may be more latency than that in the aem o2 feedback.

I think moving the sensor upstream will have a greater impact on the reaction speed of the o2s than changing to an x-series. If my inline wideband happens to sell I will switch to an x-series on the rear and see if you can notice a difference between front and rear response times, but I doubt it.

I have read some information posted by someone who tests the widebands at aem and he says what really kills o2 sensors is running richer than 11.0:1 and being closer than 5" from the turbine wheel because some actual flame can come past the wheel and scorch the sensor.

The stock o2 sensor locations are 4-5" from the turbine wheel I would say (I will try to capture some measurements later), so should be safe. Extended 2-step operation may be hard on them, but they are rated for 250 hours at 1030 celsius, so I would think you'd melt the o2 housings off the car before you would kill the sensor abnormally fast.

The bosch tech sheet actually recommends running the sensor in as hot of an exhaust as you can without overheating it for best response and accuracy.

If you want to run pre-turbo you need the pressure compensated 4 channel wideband kit from aem or similar though. The accuracy can drift as much as 20% at 30 PSI of exhaust pressure.

Edit: oh and like keith said they eliminated the free air reference chamber on the 4.9s and instead use some current strategy I don't fully understand. This should make the sensors last longer and react faster in the long run. The aem tech and others state that as the sensors age they don't usually fail outright if properly thermally controlled, they just keep getting slower.

Apparently Innovate has a very high number of sensor failures because it seems that their heater control strategy could be improved.

[KeithMac]

If you get the 4.9 sensor make sure your controller uses Bosch's own control chip, they work hand in hand and will garantee correct readings and heating strategy.

The stoich reference current is generated/ referenced from the control chip from what I've seen allowing a sealed unit (better for oem applications).

I've been dabbling with closed loop correction under full load using a gear position switch so only 3rd 4th and 5th gear allow it, 2nd gear is too quick to allow any meaningful correction.

Still mulling over leaving it like that full time or just for tuning runs..

My Zeitronix ZT-2 has been very reliable, 10 years service without a single issue, would deffinitely buy another (or a pair of zt-3's).

[Chris@Rvengeperformance]

If you get the 4.9 sensor make sure your controller uses Bosch's own control chip, they work hand in hand and will garantee correct readings and heating strategy.

The stoich reference current is generated/ referenced from the control chip from what I've seen allowing a sealed unit (better for oem applications).

I've been dabbling with closed loop correction under full load using a gear position switch so only 3rd 4th and 5th gear allow it, 2nd gear is too quick to allow any meaningful correction.

Still mulling over leaving it like that full time or just for tuning runs..

My Zeitronix ZT-2 has been very reliable, 10 years service without a single issue, would deffinitely buy another (or a pair of zt-3's).

The traditional and the 4.9 AEM wideband uses the bosch chip. The X series is a custom in house design and they have done their homework.