1 Wideband O2 pulling double duty for 2 devices....can it be done?

[Jonny Hotnuts]

I have 2 devices; a bazzaz self mapping fi and the FAST logging AF monitor.

Both devices use identical O2 sensors (even the harness plugs are the same).
I would like to run both units but not add an additional bung and a second O2 in the header.

Is it possible to splice the harness and allow both units to read from the same sensor?


-JH

[John Romero]

I just looked on bazzaz's website and the sensor is a UEGO type so no, you definitely cant share them. The device works in conjunction with a controller and the sensors are not stand alone. Hooking up two controllers to a single UEGO sensor will cause all sorts of problems including the possibility of burning out one or both of the controllers..

[hayaboosta]

I have found the logging function of the Bazzaz Performance box to be more than sufficient for recording a run.

I used BPD devices on two record setting bikes this year and give a bunch of credit to them for our success.

The only thing that may throw you off initially is mid range numbers may show lean from the fuel cut on trailing throttle.

[McRat]

Does your FI run in open loop at WOT or closed loop?  If it runs in open loop at WOT, you perhaps don't even need the O2 sensor for the injection.  On the cars I've tuned with factory FI, WOT is open loop tuning so it doesn't even read the O2 sensor.  The sensor is only used for part throttle.

Dunno about aftermarket injection though.

[V8Pinto]

The wideband controller pulses to the O2 sensor to determine it's resistance at any given temp (varies).  You'd need a high speed relay sync'd with both boxes...I wouldn't want to design it unless I was getting paid by the hour

I'd say go with two sensors.

I just started playing with the Bazzaz stuff (thanks Scott!).  I definitely see the effects of trailing throttle - maybe that's what my deal was at El Mirage...

[ModelTSteve]

What's "trailing throttle" ?

[Jonny Hotnuts]

For whatever its worth I have nothing but good things to say about the Bazzaz system.

Our first run I had it "learning" in self map mode.
Applied the map to all additional runs.

Cost of the Bazzaz FI controller: 350
Cost of the Bazzaz auto mapper: 350
Being able to push a button and self map the FI on the salt with real world environment and ram air......priceless!



Going with the 2 sensors.

[V8Pinto]

JH,

After your "learning" run, did you "apply all" the values?  Or did you just select certain cells and only  apply those (e.g. 100% tps at RPMs for top speed in top gear).

[Jonny Hotnuts]

We applied the entire suggested map. After the map was applied I made another run and the plugs looked perfect after that.

It was only after my pop made two runs that the plugs were looking lean.

I had lost a bit of sleep wondering what was the cause....nothing was changed between my runs.

Then it dawned on me (a week ago!):

I have come to the conclusion that the reason the motor was running lean was because the fuel pump was getting lower than needed voltage. We have 2 800cca batteries powering; 2 water pumps, air pump, ignition and fuel pump. I have a huge battery charger and we charge before each run....but the batteries are 2  years old. I noticed in the pit with the system on and the motor not running you could hear the pumps spool up much faster when the battery charger was hooked up. It didnt even occur to me until after the fact that my voltage must of been running much lower, even with the motor running. The stock stator only puts out about 400watts...not enough to charge the system and power the accessories.


I have already been discussing the idea of running only the ECU from the motor and use a 16v battery to power all the accessories for next year.

I will post a thread about doing this later.

-JH

[sockjohn]

I have come to the conclusion that the reason the motor was running lean was because the fuel pump was getting lower than needed voltage. We have 2 800cca batteries powering; 2 water pumps, air pump, ignition and fuel pump. I have a huge battery charger and we charge before each run....but the batteries are 2  years old. I noticed in the pit with the system on and the motor not running you could hear the pumps spool up much faster when the battery charger was hooked up. It didnt even occur to me until after the fact that my voltage must of been running much lower, even with the motor running. The stock stator only puts out about 400watts...not enough to charge the system and power the accessories.

I have already been discussing the idea of running only the ECU from the motor and use a 16v battery to power all the accessories for next year.

Are you using a marine type deep cycle/starting battery?  If not that may fix the problem. 

If you have room (and you probably don't!) a pair of big deep cycle 6V batteries in series certainly would fix it.

[hayaboosta]

We use High output stator with HO reg/rectifiers on the sand cars often.  It helps with the draw of the lighting and accessories. 

Not included in the Bazzaz instructions is the fact that after you apply the logger info to the map you need to clear the logger to record a proper new session.  Otherwise it will step on itself and you will get the map out of wack very quickly.

[Jonny Hotnuts]

Sockjohn:

They are deep cycle (Optima Yellows).

I noticed that the batteries would read 11.5-12v with everything off and drop to about 10v when the master switch (one switches turns on everything electrical) and then return to 12v after the switch was turned off.

This may be because I have a bad cell(s) in the batteries or maybe the current draw is more than what can be sustained for the amount of current available from the batteries.

I was thinking that if I powered the ECU off the stator alone and used a 16v system to power the accessories if the voltage from 16 dropped -3 or -4v I would still be at or higher (yet still within operational range) voltage than if I started with a 12v system and dropped to 9-10v at the end of the run.


Boosta:
 

I had to call Bazzaz for some info about using the system (great tech department BTW….guy got me in touch with tech at 7:45pm his time at his house!). He explained that they were pressured by the investors to release the product and the supplied manual suffered for it. He said that I was not the only one that had a hard time understanding the supplied instruction and they would make a better how to use instructions on future versions.

He also told me that “data stacking” was a problem and they would make a revision that automatically cleared the recorded data before it would re-write.

[hayaboosta]

What's "trailing throttle" ?

Deceleration or just plain "off the throttle".

[Dean Los Angeles]

What's "trailing throttle" ?

Deceleration or just plain "off the throttle".

Feathering is more like it. Some fuel systems can be problematic when you just lift a little for wheelspin.

[V8Pinto]

We use High output stator with HO reg/rectifiers on the sand cars often.  It helps with the draw of the lighting and accessories. 

Not included in the Bazzaz instructions is the fact that after you apply the logger info to the map you need to clear the logger to record a proper new session.  Otherwise it will step on itself and you will get the map out of wack very quickly.

I bet you that's what happened to me.  It definitely stepped on itself....that makes sense.