Like the title says. Everyone keeps telling me to put it in the rear rotor.

Is there a way that two wideband O2's can be averaged or something?

 

i was wondering the same thing...

 

In my RX-3 with the dual exhaust Rotary Engineering header into 1 muffler, I have 1 bosch oxygen sensor on each pipe appx 12 inches from the engine flange. Inside the car, I have a switch which allows me to toggle back and forth between front and rear header. this is the DP/DT switch from radio shack.

 

Do you notice a difference in the sensor outputs?
I am also wondering about this..

 

Well, IMHO, its a waste of hard earned cash. I should have invested on something much more accurate say the EGT (?). The gauge showed rich the whole time. I ended up unplugging it and the gauge is still there for show. I cant speak for F/I engines since Im running a IDA.

 

Well, I just bought a dual outlet header and plan to go with the full SP exhaust from RB. I am converted to FI as well and was wondering what the effect would be..
Did you have a sensor on the old exhaust setup to compare the differences?

 

i'm sure there is a way to do it. the real question is would it be worth it? i asked this same question in the EFI forum a while back and i was told the same thing ... put it on the rear rotor and call it a day. that would be the one that usually detonates first. it made sense to me ...

 

That makes sense? Please explain.

A.) O2 sensor doesn't read detonation.

B.) We have essentially two single rotor engines coupled at the E-Shaft. There's a set of injectors or carb barrels for the front rotor and a set for the rear. What if the front injectors clog or fail or a needle valve in the carb gets stuck.

If something like that happens, obviously the engine would run like *** and the operator would have to be a retard to not notice it. However, since this Wideband would be controlling my standalone, I'd rather it not try to run rear rotor only should something like that happen to the front rotor.

 

I think it'll be okay on the rear only. I will try it out, myself. You might want to get EGT sensors if you're concerned about that happening, Pele, or at least, two o2 sensors, but I don't think it'd be worth it.
You would definitely notice running on one rotor, even if the ECU is compensating and only running off the rear sensor. A carb would do the same thing if something happened to either rotor, anyways.

 

However, I do see your point if the injector cut out 50% or something less than 100%... That would be bad to have a lean rotor, but then, if you had the ability to use dual o2 sensors you would definitely know in that case.. Though it would depend on your intake style and ECU type to determine how this situation was handled on the collected intake as well, but the usual response would be to dump more fuel into both rotors.
Either way, you SHOULD know when an injector becomes clogged unless you start with a clogged one..
I really think with duals just putting it on the rear like they said will work just fine.

 

Could I mount it back in the colletor, or does it have to be X distance from the port? It's a wideband, so it'll have it's own heater and such.

 

You want it as close as possible to the port so the reading is fast/accurate. Which collector you talkin about? On the streetable header, or near the muffler on the SP exhaust? I wouldn't put it back there.. On the streetable header, I wouldn't think it'd be a problem.

 

I'd hate to drill into my header but I think its the best place since its a fast, accurate reading, plus the metal is thick enough to tap. I'd just worry about the sensor disrupting the exhaust pulse and inhibiting flow if its that close to the port.

 

it made sense because of the explanations that were given to me and yes ... i know the O2 sensors don't read detonation!

first of all, i'm not very well-versed on the fine details between different systems. so if there is a system that can handle multiple O2 sensors, i'm not yet aware of it. that was what sparked my original question when i asked - it was with reference to one of the Haltech systems. i forget which (it was well over a year ago that i asked it on this board in the EFI forums). my concern was because i was anticipating buying the RB streetport exhaust and i was concerned with how my future EFI would cope with 2 independent O2 signals.

anyway, to answer your questions with the information that was given to me back then ...

i've read (both here and on nopistons) that the reason the rear rotor usually craps out first when pushed to extremes is from detonation due to the path the coolant runs through the engine. the rear is always subject to coolant that has already transferred heat from the front and is therefore always slighty hotter. having the O2 sensor reading from the rear made sense to me because if it's relaying information to the computer based on the fuel needs of the rear, then the front will always be fine (barring any of the examples of special circumstances you mentioned, of course).

 

i believe they said it should be no more than 12 inches from the exhaust ports.