kenmosher
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?
- 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?