JNorris

iTrader: (4)

Will the following work?

Using LS1 Edit deactivate the codes for the rear O2 sensors and replace the stock sensors with either wide band O2 sensors or 700mv-1mv narrow band O2 sensors. Then use your scan tool to monitor them.

Thanks

John

ChrisB

Wide band O2 sensors require a different type of control circuit than your normal O2's.

The NTK units commonly used are 5 wire units with a 0-5v output range. There is also the issue of the heater control circuit which much maintain a constant temperature (the o2 output is very temperature dependant).

If your control circuit/box re-scales the output to a 0-1v input and you have a translation table for the corresponding a/f ratio you could do this - but you would be giving up a good bit of resolution. For data logging using a 0-5v sensor would be a better choice (AC pressure maybe?)

Bosch makes a LSM-11 sensor which is supposto be an accurized standard type O2 sensor. It will still require precise heater control though, so will still need some sort of control box.

Chris

JNorris

iTrader: (4)

I thought that the rear O2s were heated.
If so the existing heater is not precise enough?

John

wizkid

iTrader: (3)

We need a cheaper solution that logs the data vs rpms. $900 seems to be the rate right now for a unit that will do that accurately.

Surely someone can come up with better price. We all need this bad.

ERic

red ws6 99

If you want something that logs and is less than $900 it can be done for probably $400. You would need one of the diy wideband setups hooked up to a PIC stamp with serial connection (basically a PLC) and a input module for the rpm. The parts to make a PIC stamp with serial run about $40, not sure on the imput module costs but should not be much more than $50.

I am just a loly mechanical engineer if you know someone with electronics and programming experience (can do the programming maybe) let me know I can get them pointed in the right direction. I just dont have the time to develop the stuff, to busy building a turbo system.

Gary

ChrisB

Yep, stock heater circuit is really just a +12v source. It doesn't regulate the temperature at all. You need a circuit which will maintain a constant temperature.

wizkid:
The best thing to do is really to find a 0-5v input on the vehicle. On LT1's the AC pressure sender is 0-5v and can be adapted for this (as it causes no problems when unplugged (unless you turn on the AC - the the clutch probably wont engage)).

If you do it like this then you are keeping your time domain constant for all sensors - e.g. at a given datapoint you know all sensors are in phase with the wideband reading. It also simplifies the entire data collection process as you just log like normal with whatever software you use.

Chris

red ws6 99

Yes the rear o2s are heat but probably a different control circuit than say the ntk or bosch lm type sensor. If you want wideband you can make one your self for around $300 (sensor costs $250). Do a search on the internet for diy wibeband. Their are two sites www.diy-efi.org and one in australia that have schematics and parts list to make one. They both use a ntk (honda fast burn uego sensor I believe). The one on diy-efi is not to good, just outputs the voltage then you have to look on a table to see afr. With a lot of tweaking you might get one to work with the stock system. As suggested probably leave it on 0-5v output.

Gary

JNorris

iTrader: (4)

Guys thanks for the feed back.

So you will need a circuit that will maintain a constant temperature based on the current draw of the sensor. Current flow will change based on the exhaust temperature (WOT, cruise, rich, lean) and the installation location of the sensor.

What is the voltage resolution (.0, .00) of the AC pressure sender input on the PCM?

What would be the best O2 sensor to use?
The O2 sensor is ~$140 at NAPA.

The link to DIY-EFI above has a lot of good info.

I wonder how well it works?

Thanks

John

<small>[ July 17, 2002, 10:44 AM: Message edited by: JNorris ]</small>

Magnus

iTrader: (4)

http://www.diy-wb.org