Does your dyno have a spare wideband sensor? We use them in the tailpipe when a bung is not available and have had no such problems. We use Bosch 6 wire wideband sensor. You will get a lean reading at idle due to reversion but should be pretty accurate under full throttle. Obviously you're not running that lean or you'd have much higher power numbers.

 

OK, I just got back from another road test.....damn...I am getting good at this..hope the neighbors dont complain.

I went ahead and datalogged RPM and A/F on the Profec. I did a WOT run in 2nd gear and I swear...i was staring at the AEM guage the whole time. At 6400...just before I let off, the last thing I saw on the AEM guage was 12.4:1. Remember I am running 7psi of boost..so I am a bit leaner than I would like becuase I havent done the fuel system upgrade yet.

I went back and slow-mo reviewed the log. Guess what....at 6400, the Profec logged exactly 12.4:1. The two readings are identical.

 

Thanks for the link Tim. The gains are impressive with the resonated test pipe.

 

Yeah, I did some research. It seems that the wideband O2 sensors actually put out positive and negative volts. They range from like +.2 to -.2 depending on whether you are lean or rich compared to stoich. The display is based on this number.

The output is an algebraic function that yields a 0-5v output. For instance, the PLX system uses AFR = 2 * volts + 10. Essentially, y = mx + b, which yields a linear graph. Other manufacturers, like zeitronix and AEM use exponential functions. (I guess, by looking at the curve.) Still others give adjustable outputs.

I agree, that if the output is linear, and you can set starting/ending volt and afr values, that you would have no problems. But what about the non-linear setups? They advertise being used in conjucntion with a stand alone.

Zietronix says that most stand-alones offer multiple adjustable values so that you can adjust for the curve, but what is going on with gq's profec. He hasn't entered anything, and his non-linear output is registering perfectly on the profec.

Hey derek, how do you like the ZT-2? And what is your 0-5v connected to? I want to find a way to get an analog gauge to work in conjunction with the ZT-2, any ideas?

 

Thought I would thow up a A/F chart comparison with the
Test Pipes w/stock exhaust (Kinetix) in Red
High Flow cats w/stock exhaust (Kinetix) in Blue
Test Pipes with Evo2 in Green



I will post the HP and Torque charts in this thread
https://my350z.com/forum/showthread....threadid=67663

 

My ZT-2 is connected to an E-01. I've been going back and forth with Zietronix about the accuracy of the device, and from their responses they seem to think that close is good enough.

12.6 runs really good on my car, 13.1 is detonating, so that 0.5 is pretty important to me. This seems like a pretty bull**** answer, to pay $300 for something that claims 0.1 accuracy and then be told that its 0.5 close.

-D

 

I should add that they offered to reprogram the control unit for a linear curve and I might take them up on that.

Right now I would expect the curve looks like the AEM one.

-D

 

Thanks Tim, still peculiar why the A/F w/ Test Pipe + Stock Exhaust would hover around 13.5+ from 3k on. Where the other 2 A/F (HF Cats + Stock and Test Pipe + Evo2) would start it's descent at 4K to a nice comfortable 11+. I hope mine will look similar to the test pipe + Evo2. I will test once I get my car back.

 

The #s would have to be off (from the tail pipe sensor)

I posted, so the curvers of the graph could be seen

 

Thanks again Tim. I figure the # got to be off or you're risking a lot at those level.