I've read that some of you have put the O2 sensor in your mid year Vette, can someone tell me the reason's for it? Is it to monitor your exhaust reading for a indash gauge or such?

 

I don't personally have an O2 sensor on my car, mostly because I don't want to cut a hole in my original sidepipes to install a bung. But, it is definitely a good idea. The reason for installing an 02 sensor is to monitor AF ratio for tuning purposes. There are different types of systems...I personally would use a wide band AF meter with an O2 sensor, if anything.

Assuming you know something about engines and chemistry...an engine likes an air-fuel ratio of 14.7 as "ideal." By using an O2 sensor, you can tell how far off you are with how your car is tuned. When you go wide-open-throttle and during other drive events, the air-fuel ratio will differ greatly and this is not usually the best thing...ideally you don't want to go rich or lean of 14.7

Reading that back through, I realize its a bit of a scatterbrained response. Hope it helps a little...

To add one thing...all cars today come with O2 sensors that are used by the computer to control the amount of air and fuel that are allowed enter the engine under various drive conditions. The only difference is, instead of using a carburetor, todays computers control the pulse width of the fuel injector.

 

Yes it does, and thanks for the explanation. As for the location of the bung, if you were running header, not sidepipes where would you weld it in? And who supplies the kits. This would sound like something worthwhile if you were to install a new exhaust.......no?

As for as costs lets see if I can get the ball rolling with approximate pricing.

AC Delco 02 Sensor---------$70.00
Bung-------------------------?
Gauge or Meter--------------?
Misc--------------------------?
Wiring-----------------------?
Labour-----------------------?

 

Summit Racing

 

Summit Racing sells 02 sensor kits for C3? I never knew that, guess I'm going to have to do a search.



Anyone have any idea's? I'm hoping it's not in the headers themselves.

 

Bung goes in the collector, either side. LM-1 is the most popular wideband AF meter, it's expensive though. If you decide to get a LM-1, then it comes with an O2 sensor, wiring & a bung.

Norval did a write-up on using a wideband & his findings. Search is your friend.

 

I have an LM-1, and I had bungs welded on each side right behind the header collector.

 

Would just like to expand on a point or two for discussion, but I've come to a little different understanding with regard to AFR. Maybe I'm misunderstanding something.

Plus or minus 14.7 being the Stoich Air/Fuel/Ratio (AFR) that GM and other later model computers strive to (for fuel economy and emissions as well as other reasons), this is not necessarily optimum to make the most horsepower (and safely) if that is a goal.

When tuning forced inductions applications (Superchargers, Turbos, Nitrous), at WOT (Wide Open Throttle) not only is it safer to run a richer mix (around 11-12:1) to help avoid detonation but in may cases will make more power. Most Naturally Aspirated (Carburated and EFI) higher performance motors are tuned around 13:1 AFR at WOT but that depends on the motor, modifications, and temp and barometric parameters.

The only accurate way to determine what your actual AFR is is to use a WIDEBAND O2 sensor such as the Innovate LC-1 or LM-1 or comparable. The stock Narrowband O2 sensors are just that, narrowband. They operate within a small window of tolerance around that 14.7 big brother stoich figure as designed. O2 sensors are expensive, and WBo2 more expensive, but if you want to truly test and tune AFR, a WBo2 is the ticket.

I use a wideband even in carburated application tuning to see exactly what AFR the motor is producing (As well as how it is running and how much power is it making). Obviously in a carb'd app you adjust the carburetor and ignition as oppsed to an ectronically controlled EFI application of adjusting airflow, timing, injector rates, etc. with a few clicks.

I'd be curious what others that are using a WBo2 for with carb'd apps and if for tuning what AFR they are shooting for or making the most power at (and what mods)?

 

page down on my carb page in sig.

 

I didn't realise they were that expensive, I'll check Ebay for possible better pricing. Next time I talk to Norval I'll pick his brain. Thanks


Next time I see your car I'll have to take a look. Thanks Bruce.

Thank Matt, will take a look.

 

oxygen sensors really arn't too bad as far as price if you look around. You can pick up a narrowband for about $30-$50 new and a wide band for just a bit more. All the wideband kits are expensive but if you research and find cars that came with a wideband stock which is within the last 5-10 years you can usually get a decent price on an oem replacement. Which isn't any worse then a kit as far as quality.

Narrowbands are also useful as they work great in the big flashing warning light way. You'll know if your lean, stoic, or rich. Which at the very least will keep you from blowing up on your motor on the forced induction route.