I have a Racing Beat full race exhaust on my SA and im looking in to a air fuel setup. i guy i work with has a REALLY nice wideband and i would like to hook it up for tuning it. I just not sure what rotor i should put it on or where to put it period. I plan on drilling for it and welding on the fitting for the sensor jsut not sure where. can anyone help?

thanks robert

 

I installed mine on the collector before it goes over the rear axle. this is a little far back so you will get a delayed reading but the most simple spot to put see the thread my new 3" ex

 

I saw your exhaust and looks nice, you say its a little delayed but the reading is still accurate right?? This is new to me so im looking for any info

 

Most wideband O2 sensors need heat to work accurately. Install it in the rear header tube or at the collector.

 

I put mine near the ends of the header tubes on a RB road race header. I have one in each tube. IIRC theyre supposed to be 24" from the port outlet to be optimal. Too close ahd you'll roast it and too far there will be a delay in the readings. I cant remember exactly where I read that.


Scott dont widebands use the internal heater to keep the sensor at the optimal temp? AFAIK thats how they are superior to narrow bands.

 

Widebands do have a pre heater for calibration. I do not know for sure if they heat all the time. I doubt that they do. When mounting the O2 in the back, not only is there a heat issue and a delay issue, the exhaust flow itself pulses and actually pulls in small amounts of outside air, giving inaccurate readings.

 

Rx7carl so yuo have two sensors and two gauges?? is that the setup your using, because i too have the rb race header and mid pipes. if i was to use two would it be ok to use the narrow band, for cost reasons?

 

You do not want the wideband sensor to be too close to the engine. A wideband sensor maintains it's accuracy by holding the sensor heat at an exact level. The sensor heater is on almost all the time. It can heat the sensor up if it is too far but it cannot cool it down if it is too close.

Rotary exhaust is hotter than piston exhaust so it would probably be good to add a foot to the recommended piston distance.

 

Most of the aftermarket O2 sensors, have a warranty disclamer stating "Not for use with 2 stroke engines". I often worry about mine. If it takes a crap while it's still under warranty, will they consider a Rotary a 2 stroke? LOL!!!!!!!

 

Good point Trochoid. dilution of the exhaust gas by outside air will throw off the readings beyond hope. On a related note. You need to make sure your exhaust has no leaks at all or youll have the same problem.

Rob yes I used to tune with dual EGT and dual narrowbands. The Wideband is wayyy better, more accurate and the data logging is the way to go. I'm still learning it and playing around with the new toy.

edmcquirk, thanks for the info.

 

So, Rx7carl, do you use a manual toggle switch between the two sensors while using a single wideband, I assume? I'm interested in doing such a setup, too. Thanks!

 

Damn...

'cause the only place they collect is just before the muffler.. are you sure inside air gets pulled in that far? I *really* don't want to have to shell out double, especially since I was going to mount the gauge where the stock clock is, and I've only got one clock.

I *know* it's better, 'cause you get readings on each individual rotor... but still...

Jon

Edit: hmm... I like Chas' idea.. is that do-able? Isn't the lambda cable special in some way? I haven't even seen one of these setups up close yet

 

that is exactly what i was planning on doing. i was going to get two o2 sensor and have a 3 posistion toggle left and right be each rotor and then the center or home posistion be off. i dont see any reason that would not work. im just looking for a switch now.

 

Chas, your not supposed to leave a wideband sensor in the exhaust unpowered. So you need bung plugs to plug the holes when your not tuning. And switch the sensor back and forth when tuning. Right now Im still too busy to get more serious with it, but thats how you need to use it.

Jon, remember the exhaust pulses. It will pull air into the exhaust to some degree. How far will depend on RPM (at what RPM is the pipe tuning most effective). Better safe than sorry.

Rob, I hops that answers your question.

 

so when tuning have a wideband with a toggle switch and two o2 sensors and when tuning switch back and forth for to get a reading for each rotor and when done pull it out and plug it up. is that what your saying

if so im with you on that
thanks for the info
robert

 

Don't worry about that at all. The rotary engine is most assuredly a 4 stroke with separate and distinct 1) air-fuel intake 2) Compression 3) Ignition and 4) Exhaust.

A 2 stroke piston engine's piston combusts once every power shaft revolution.
A 4 stroke piston engine's piston combusts once every two power shaft revolutions.
A rotary engine's rotor is combusted three times (once for each of the rotor's sides) for every power shaft revolution.

 

i emailed tech service at Racing Beat and asked for suggestions on O2 placements and here is what i got in reply


Your question was forwarded to Jim Mederer, Racing Beat's co-founder and chief engineer, for review. The following is his reply to your inquiry:

You have 4 choices - none great: place the sensor after the collector; use 2 complete sensor systems; use 2 sensors and switch between them electrically; or use 1 sensor and read the cylinders one at a time. All these choices have good and bad features - you will have to select the best one for you.

Jim Mederer

 

Ok. I'm not a DEDEDEE. I mean the fact of a Rotary burning oil. Most O2 sensors don't last long with an engine thats uses oil/gas mix.

 

robs seven, please update this thread per your progress. I want to do this, too...after a paintjob; so may not be this year.lol Thanks!