O2 sensor

[Robber98]

Im just wondering what o2 sensor is needed for a halmeter a/f ratio gauge and where the best place to get one is. Thanks Rob Murray

[sracing]

Originally Posted by Robber98

Im just wondering what o2 sensor is needed for a halmeter a/f ratio gauge and where the best place to get one is. Thanks Rob Murray

You can use almost any stock narrow band 3 wire O2 sensor from any auto parts store. They can be had for as low as $25.

The poblem is, the cheap halmeter <$200 unit is nothing but a light show. It uses a narrow band sensor that only reads with any resolution at 14.5 to 14.8 or so. The Halmeter itself is nothing but a LED driver.

You cannot use this for tuning any engine. It is only good to tell you if it is idling at near the proper a/f ratio. Under any throttle dynamics, it is just a light show that flickers all over the place. You need a Wide Band System to do any real tuning or checking of your a/f ratio, A wide band system is going to cost well over $200. You need to look at the AEM or Innovate units.

Also keep in mind that either type of sensor (narrow or wide band) have a limited lfe when using leaded fuels. (20 to 100 hrs at best)

If you want to use an o2 system for tuning (an excellent idea), give us a call and we can help with the best solutions.

[Hardingfv32]

Originally Posted by sracing

....It uses a narrow band sensor that only reads with any resolution at 14.5 to 14.8 or so....

Your carb should be set at 12.5 to 13.0 for max power. That is why the gage is of no value. It does not provide information about this range.

Brian

[blackhole]

Don't waste your money!

Any 02 sensor can not give you consistent and true readings with any carburated engine. Especially with an open style exhaust the the o2 sensor would have to be right after the exhaust ports of all 4 cylinders which is not possible.

The 02 sensor on our exhaust would have to be placed near the end of the exhaust but than it has the potential of sucking outside oxygen.

To get the best results you would have to hook your car to a 4 gas analyser under load (dyno). Most dynos that anyone has in the formula vee community does not have this feature.

We have a 5 gas analyser hooked up to our dyno.

Rob if you would like to come down we can tune your engine on our dyno and gas analyser and it would be cheaper than buying the whole wide band 02 sensor kit.

[Rolling Stone]

Originally Posted by blackhole

Don't waste your money!

Any 02 sensor can not give you consistent and true readings with any carburated engine. Especially with an open style exhaust the the o2 sensor would have to be right after the exhaust ports of all 4 cylinders which is not possible.

The 02 sensor on our exhaust would have to be placed near the end of the exhaust but than it has the potential of sucking outside oxygen.

To get the best results you would have to hook your car to a 4 gas analyser under load (dyno). Most dynos that anyone has in the formula vee community does not have this feature.

We have a 5 gas analyser hooked up to our dyno.

Rob if you would like to come down we can tune your engine on our dyno and gas analyser and it would be cheaper than buying the whole wide band 02 sensor kit.

AND!!you get a free sausage on a bun thrown in...Go for it Rob,I certainly would if it wasnt so far for me,but ignore Kevins dad as he swears a lot when the Dyno is runningIts all the LUCAS wiring he has on the Dyno

[sracing]

If you can get your car down to Kapelke it is a good idea. I do disagree with his assessment of a Wide Band O2 as "being a waste of time.". You are tuning through the max Peak torque and max HP range. You will not suck outside air at those RPM's. We have used wide band o2's at the collector on closed systems and at the tail pipe on the chassis dyno and use them on engine dynos before and after the collector. There is absolutely no difference at RPM. We also measure actual air flow and fuel flow and it also compares to the wide band o2.

If you are tuning for idle and polutant testing, a gas analyzer is fine. However for racing a wide band 02 is fine and will work perfectly. It is fast enough, can be fed to a d/a system, and is reasonably priced.