Anyone having knowledge and experience with the Zeitronix Zt-2 wideband who can answer a few basic noobie questions via email, please get back to me at curthaag@brinet.com.
Thanx.

 

why not ask them here? I have a Zeitronix and so do many others, you aint gonna get flamed if they arent stupid questions like "what is a wideband?". Get the drift...

 

OK guys, here goes.
I have the plain vanilla version Zeitronix Zt-2 without the LCD and don’t plan on a permanent installation, but only minor, one-time tweaking of the AFPR after installation of the SC, Walbro, 370’s and JWT ECU (as I don’t want to mess around with the JWT timing on the advice of StephenMax). No Vortech FMU. Oh, and Cattman headers. Without any convincing otherwise, I’m planning on data logging only the AFR against RPM, wanting to make sure that I’m not running to far from reasonable AFR’s, especially in the upper RPM range under WOT. And I understand that what I’m thinking will not fine tune the AFR at various, individual RPM segments, but instead move the whole curve up or down slightly across the entire RPM range during open-loop.
So, with that as an objective, my sense of it is that I need to get an 02 bung welded in just before the CAT, and wire up the Zeitronix 0s sensor, run the RPM signal off of the speedo TAM screw, tie into switched 12V power and a ground. Did I miss anything?
I’m not intending to do dyno runs but to get AFR readings during 2nd gear acceleration runs. Good or bad idea? I’m assuming that the Zeitronix unit itself only processes the input, storing/saving nothing, and that it has to be hooked into a laptop realtime during the runs for the data to be saved. True/false? I don’t have the laptop yet that I’ll be using, but does the Zeitronix software explain this part a whole lot more clearly than their paper installation instructions? Can the laptop just be left sitting on the passenger seat during the runs, capturing all the data, or does someone have to be doing something with it during the runs. And can data for several runs be captured and then each run’s data be analyzed separately. Is the amount of data that can be captured and stored on the laptop limited only to the available storage space on the laptop? Any questions/points you can come up with that I’ve not thought of?
I’m sure there are hard-core guys who would make a case that I should also get a VAFC or EU and go all the way with the tuning. One the other hand, some will think that I should just install the AFPR and Walbro, adjust the base FP back down to stock, install the SC and injectors, trust that JWT’s SC program on the ECU is good enough and call it a day. I want to go a step beyond the mere plug-n-play, but not go crazy. So, there you have it. Any knowledgeable advice from experience is appreciated.

 

thats exactly how I have it installed. all you have to do is press ENTER on the laptop to start/ stop the datalogging. you can split on large datalog into smaller ones.

I just installed the Zt-2 the other day, and want to tune with it and my VAFC2, as well. But I'm not exactly sure how to tune with the VAFC2. I wired my VAFC2 according to this: http://jime.homeip.net/S-AFCII4thGen.html (the 4th gen and yes, i know it says SAFC2). and when I go into the section where you have the RPMs, and you have the option of giving it a plus or minus number for that specific RPM. What exactly does giving a higher positive number do, than a lower negative number? Does the way my VAFC2 is wired up affect the effectiveness of changing the +/- for the specific RPM?

Thanks

 

Okay to answer both of you guys questions, here you go:
First off all Curt, the only thing that you can add to the wiring is TPS (that way you can see at what point in time you're under WOT). Other than that, its perfectly fine to just use the ZT-2 to datalog A/F.
The unit itself like you said is just a instructment convert the o2 sensor voltage into A/F ratio which is read thru your laptop. You can either watch it realtime and/or after a run, save it for later reference. There is no modification that you can do under the program since its just a monitor. To adjust the A/F again like you said would require a SAFC/EU or something like that. If you plan on street tunning, I would perfer that you do it on the highway where you can consistantly do 3rd gear pulls because second its just too short for any proper tunning or datalogging.

As for the SAFC/VAFC tuning. Once you capture the data from the wideband, you can modify the "richness/leaness" of that specific rpm via the +/- increments: "+" = rich, "-" = lean. The SAFC is done at a percentage which requires a little math, I never dealt with a VAFC so I don't know exactly how its done but the idea is the same. I always take the current A/F divided by the targeted A/F, mulitple that by 100; then subtract that number by 100 which will give you the rough estimate of the percentage of change you need. A number less that 100 after you multiple by 100 will mean you're gonna use the "-", since you be leaning out the A/F, vice versa.
I hope this help and good luck.

 

what is the perfect AFR we are looking for? is it supposed to be constant throughout the entire RPM range of the run? what is a safe range for the AFR for us?

 

its going to vary per car, and based on your mods. 13.0 - 13.5 is a number many aim for.

 

Let's see, 3rd gear at 7200 RPM.....hmmmm......looks like about 110mph. Good reasoning, but I think not. Although I have a couple of local Sate Trooper friends, I don't want to test our friendship that way. But thanx for the rest of the input.

 

should it be 3rd gear in autos as well as manuals?

 

I've heard some do it in 2nd for autos. but 3rd would work. Never heard of anyone able to max out 4th gear on their car

 

3rd gear brings me to 120 if i redline, thats a little high. maybe 3rd works for a 6spd, but i think anything else should do 2nd for safety purposes. either that or take some runs on an empty highway, then its ok

 

"Then it's OK?" Obviously words of wisdom coming from experience and maturity. Depending upon the state, get caught (if you don't kill yourself) and you can be facing jail time, a felony conviction, losing your insurance, heavy fines, etc. And as an employer, I'd have to seriously question the judgement of any employee who'd do that. On the other hand, I was once young and stupid too (but fortunately, managed to survive it).
Sorry about the flame, but I'd hope that your father would have said this to you if he had heard you say it! He didn't....so I said it.

 

I understand where you coming from. If this is an issue, then tune on a dyno that is the savest place to do it. Even if you tune in 2nd gear with a 7200rpm redline, you're gonna be speeding anyways not saying that 120mph is the same as 70ish mph but either way you're gonna endanger other people on the road. So the most mature, smart way is a dyno. We're merely suggesting the optimal condition to get your car tuned properly, its your decision to follow them or not.

my.02

 

thanks dad, but you could have saved it for someone that didnt already know that.

 

More like 130 mph. Don't believe the dash. My dyno data shows 6550 and 130.xx mph. My dash says 6700 and 130.

 

yeah I had similiar reading but thought it was perhaps incorrect.. hmm.

 

Wuts up dude, i remember you telling me this same method. but does anyone else use this? or can anyone else vouch for it?

 

Long time no speak. I believe Steven88 used this method too and it worked fine for him, I don't know what other people has been using to figure the AF so I like to find out too for future references.

 

Well i got an old dyno sheet i had, and used ur calculations to tune with my vafc, car feels awsome specially at top end. Monday i should be receiving my LC1 WB. =) iv added few things after that dyno sheet i used (00vi, 190 walbro, afpr.) so maybe my a/f curve is different. this week i should be tuned properly