Wide Band O2 is amazing ... - GN and T-Type Performance Enthusiasts (GNTTYPE) Forums

kenmosher · #1 01-07-2005, 01:07 PM

Got a wide band O2 system to play with the other day ... this was used on the dyno while playing with tuning my motor out.

- PLX Devices M300 Wideband Controller using the Bosch Sensor

The heater warmup on this device was about 45 seconds and it has a built in display that shows "Air" when it's ready. It has a 0-5v output (and a narrow band 0-1 volt output as well) and we hooked it up to the dyno datalogger channel and the DFI.

There is a 0-5v output that we used to feed the dyno datalogger and the DFI. The dyno required a simple procedure to calibrate the channel for the curve of the box (it's basically linear) DFI has a "generic WB" option that seems pretty darn close to what this controller provided.

This display was a nice "double check" to the datalogger and DFI, since it is internally calibrated within the controller. The dyno seemed to be pretty much spot on (off by less than 0.03 AFR). DFI was a little further adrift, but not much (maybe 0.1 AFR) and I'll admit I didn't think the difference was big enough to use DFI's "custom curve" option.

The data was amazing! It showed that a lot of assumptions we'd made were a bit off and that we needed to work on the VE to get the correction factors for closed loop fueling in line. It's really cool because you can monitor the torque along the curve and see the AFR and change just that area to see if you have maximized the potential. Using the EGT probe just before the turbo, it was showing about 1200 degrees was pretty close to optimal, but we probably need to see some more data.

We kind of snuck up on the tune, but found that somewhere around 11.8-12.0:1 made best torque and power. We made almost 690 ft/lbs of torque at 4600 RPM and we're zeroing in on maintaining that all the rest of the way up the RPM band when we whistled a head gasket. Looks like an outside water passage is leaking (prettty badly) ... so today I'll take the heads off and see what we see. I'm thinking of changing over to Cometics (from the Lockwires).

Any comments on the Cometics?

GNXDad · #2 01-10-2005, 04:57 PM

I have heard of these WB 02 sensors that you hook up to tuning software. Where do you hook them up on the car? What exactly do they do and where do you get them at?

TIA

kenmosher · #3 01-10-2005, 05:03 PM

Several vendors sell different kits ...

Innovate's LM1
PLX Devices
FJO Racing
DIY wide band kit
etc.

Take a look at the websites (http://www.plxdevices.com) for the first one I tested. They even have a little video of one in use on the car ...

On the GN, you'd want to put the bung down towards the end of the downpipe to help protect the sensor from overheating.

Turbo2nr · #4 01-10-2005, 09:57 PM

I've heard about 6" from turbo, 02 facing down to keep condensation off of sensor (bung on top). How about using the NB output for a factory ECM? Good? Bad? Why?

Seems like a good WB sensor would outlast a NB non-heated sensor like 10x over.

Anyone??

The info you can get from a NB kind of sucks compaired to a WB. I'd like to know what is really going on. Glad to see prices of WB units falling. I remember when they were very expensive, and used only for dynos, and top-notch racers, with sponsors.

kenmosher · #5 01-11-2005, 11:15 AM

One killer of WB O2s is cold "shock" if you get moisture sprayed on a hot sensor or sensor heater.

Location in front of the turbo can overpower the heater circuit, due to the extreme temps and backpressure can drastically affect readings with a WB (and there's a lot of it before the turbo). I've seen a couple folks do it successfully, but the manufacturer's data says not to do it.

As far as distance from the turbo, shouldn't make much difference, as long as the exhaust isn't leaky upstream of the turbo. The heater keeps the sensor stable (and is critical for accurate readings).

The NB output would work for the factory ECM, although in our application I think it wouldn't really have any advantage over a stock setup, since you probably shouldn't mount it in the stock location.

Turbo2nr · #6 01-11-2005, 12:34 PM

You need a certian air flow for sensor to work right. Too close top the swirling turbulant gas just after turbo is bad as per manufac. data. At least six inches is the rule. Also, the advantage of using a high dollar WB for a NB sensor is the lead resistance (see my previous post). I get tired of swapping out 02s like changing my underware. See?