I think there is a way to plug the wideband readings from PLX into the SMT6 and I will try to do it.

 

like i said there's a way
but just to use the smt-6 like i data logguer i wouldn't do it
you could even hook it up so the reading on the wideband will make the smt-6 act like a closed loop ECU but that's another story

i think the smt-6 is set-upped for a strange 0-3 O2 sensor. .quite useless for us

 

when i called perfectpower thy said that the O2 volatge MAX was 1v. the LOOPHOLE here is that now i have found out that the factory CVVT engines use a wideband O2 sensor that runs....... 0-1 volt!!! :-O it would be interesting to see how the voltag readings would compare at each mixture point.

not sure about other units but the PLX box itself reads the 0-5v input from the wideband, and has an output (if you choose to use it) for 0-1v. so what i did is hook the wideband in the downstream location and use the PLX output to give reading to the ECU. i dont think matts car was running a cat though and we already had a CELfrom the auto/manual swap but the car ran beautifully at 7psi (max- centrifugal supercharger) and keeping it around 13:1 in the higher RPM. under part throttle and low RPM (just cruising) it was set anywhere between 14 and 17:1, the car seemed to like it and gas mileage was still very good.

if the SMT does have a data logger (which i want to say that it doesnt but i could be wrong) then i would see NO PRBLEM with the processor not being able to keep up in 'real time.' its a 64 bit processor it has no problem keeping up. the narrowband reading refreshed just as fast as the PLX box display, and the A/F reading was 'pretty' close but not accurate enough for my liking. the perfectpower website states "Lambda Signal Tuning" but no mention of a datalogger and again when i called the place they claimed no more than a 1v input for the O2 sensor. i would seriously consider a betaII sensor on my next install which may be right around the corner.

i really dont believe that the SMT has the ability to adjust injector pulse based on an O2 input. if i am wrong then please let me know because this would be a HUGE feature that would (if it already hasnt been done lol) truly set it apart from any other piggyback system i have ever seen ro read about. again running this off of a stock narrowband or even the narrowband output of a wideband setup isnt too accurate, hence teh reason why i threw out the BETAII sensor info wink1.gif

 

Okay so the wideband O2 sensor gives a more detailed look at the exhaust flow, I understand that. But why would it be useful to switch the wideband to narrowband? The way I see it is that with this conversion you lose the ability of the wideband. Unless the conversion still keeps the info that the wideband sees and compresses it to work for the SMT's 1V limit.

But as you say, with the Beta II sensor output you think that the SMT-6 would be able to react better than with a regular PLX wideband due to this little conversion device? If so it might be an option.

Oddessit, what were you talking about. Were you going to use the PLX as a 1v output?

 

Conversion that I was talking about was just to eliminate o2 sensor and put wideband instead of it, still get readings from it like a normal wideband should work, but trick the ECU that you have a regular narrowband.

I know that SMT6 has a wire that can be connected to the wideband and read wideband readings, but I need to make sure that I'm right and what wires go to other wires.

 

hmm...

the bosch or most any other wideband O2 sensor reads 0-5 volts. a normal wideband O2 datalogger or display will read 0-5 volts. the PLX that i described has an optional 1v output so that you can replace the rear O2 with the wideband and wire up that output to the ECU so it doesnt know the difference.

the SMT can ONLY use this as an input, since it is not capable of a 0-5v input. just like the hyundai ECU would go haywire or worse if it saw say 4 volts from the O2 sensor. hence the reason why to hook the wideband to the MT you either need to convert it back down to its range, or find a 0-1v wideband sensor. or just not hook the wideband to the SMT and use a seperate display/logger.

 

I just talked to the dealer of SMT6 and here is two of our emails:

Mine:
"Got the package today smile.gif

Have another question to you. I found that there is a way of having a
wideband readings displayed in the program. It would be really nice and easy
to simply have a log of what AFR's I had when I was driving, and then just
sit down and turn something up or down instead of looking at the wideband
monitor all the time. So, do you know how to connect my SMT6 to the
wideband? I have PLX M-300 if that helps, and can provide you with a wiring
diagram if needed.

Thanks

Pashka"

His:
"you would connect the 5v linear output wire from the WB-O2 to the O2 input
on the SMT, you would then go into the SMT software and in the lower left
hand corner click on "setup display", then click "advanced settings" you
will see "AFR input voltage" change this to 0 min 5 max. If you have trouble
tell me.

Thank you,
Mike Lough"

Linear output wire is the white one on the M300 and I just asked him what the O2 input wire is on SMT. Will post once I get an answer from him.

 

Ohhh, okay I see where you are going with this. My basic deal was that I was under the impression that the SMT-6 needed to have the O2 sensor hooked up to function correctly. But from beppomarx's last post it seems like having the wideband O2 was just an additional function that we're not sure the SMT-6 is even capable of.

Data logging the info would be great but like Denssit said, it would act like a closed loop ECU. Do we want that? The SMT-6 will be fighting with the ECU over control of the fuel, no?

What would be the purpose of the Data-Logger for the O2 sensor? Just to have reference to see when you hit a lean/rich spot?

 

Yes, SMT6 can be used by itself without O2 sensor, but having a data log is very nice since you can just look at your RPMs and your AFRs and make corrections right away instead of driving 10000X times looking at your AFRs on the wideband display, correcting, then driving some more, correcting some more.......

It should not act as a closed loop ecu. You will be the one making corrections and AFRs from your wideband will be just a reference.

 

Yup it's all clear now. And the display you're talking about is just like a regular A/F gauge I'll assume.
So the myth about the voltage is broken. It can be changed from 0-5v to read what the WB is sending. Awesome. This little device gets better by the minute.