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post #16 of 33 Old 06-13-2017, 03:00 PM
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Originally Posted by Moondoggy-X View Post
While at wide open throttle, the target afr actually changed with the rpm. It started at about 11.9 and dropped to 11.1 at the top of the rpm range. The actual afr bottomed out at 12.08 and dis not move.
Ah, this WOT map would be the highest-load row of the target-AFR table. Typically mid-range RPM AFR is leaner for quicker-response and torque. Getting richer in the upper-RPMs for safety.

Actual AFR being leaner than desired may be a clue of something, not sure what...
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post #17 of 33 Old 06-21-2017, 08:21 AM
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You are correct.. thats quite rich even for a modern car. 12.9 on an NA engine at WOT is what I usually tuned for on my old ride.



Doggy, the decel data is correct as the engine isnt under load and thus not geting gas. nothing to worry about..



Now usually on the hwy, the AFR's should be lean as the engine isnt under *much load.. usually *some manufacturers lean out to 16's to save gas for hwy driving.


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post #18 of 33 Old 06-23-2017, 07:12 PM
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Originally Posted by Moondoggy-X View Post
While at wide open throttle, the target afr actually changed with the rpm. It started at about 11.9 and dropped to 11.1 at the top of the rpm range. The actual afr bottomed out at 12.08 and dis not move.
I will add that we both are experiencing this 12.08 air/fuel ratio, bottom out scenario. And we have had our cars tuned by two different tuners. At least this is how OBD2 is transmitting the air/fuel ratio data.

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post #19 of 33 Old 06-23-2017, 09:08 PM
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I guess thats where toyota thot it was safe at WOT.. they do try to keep things in the safe zone


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post #20 of 33 Old 06-24-2017, 11:01 AM Thread Starter
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Here's a better look for our tech heads

Notice that no matter the situation, the afr never goes below 12.08 or above 18.12. Not one bit. That's why I think the that is just the limits of what the sensors and/or ecu can "measure" and the actual afr at WOT is actually quite a bit lower. It has to be. Even if the 12.08 is the somehow lowest afr the car could achieve despite the targets, no way it would hold a steady 12.08:1 ratio throughout the entire rpm range.

As far as my ocd is concerned, as long as the numbers are accurate between 12.08 and 18.12, its ok. I obviously want to keep well within that range anyway. Hopefully,
my next tune leans the car up a bit.







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post #21 of 33 Old 06-24-2017, 11:34 AM
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My 93 Corolla (Prizm) would peg the AEM wideband full rich under WOT near fuel cut I suspect you're right that it may be richer at higher RPM than it's indicating, the only way to confirm is with a stand alone wideband sensor, which would be beneficial to have.
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post #22 of 33 Old 06-24-2017, 04:10 PM
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Whoa! What program did you use to be able to log the data this way? I see something about 'ecuEdit_OBDCan'. Is this part of TorquePro or something else? I'd love to graph information like this.

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post #23 of 33 Old 06-24-2017, 07:31 PM Thread Starter
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Originally Posted by Myxalplyx View Post
Whoa! What program did you use to be able to log the data this way? I see something about 'ecuEdit_OBDCan'. Is this part of TorquePro or something else? I'd love to graph information like this.
The program is called EcuEdit. Its not cheap, but it is awesome for logging. You will need a laptop for the program. I don't know if it works with a bluetooth obd2 adapter or not. I have a wired tractrix 2.0 cable.

http://www.epifansoft.com

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post #24 of 33 Old 06-25-2017, 07:31 AM
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Quote:
Originally Posted by Moondoggy-X View Post
Here's a better look for our tech heads

Notice that no matter the situation, the afr never goes below 12.08 or above 18.12. Not one bit. That's why I think the that is just the limits of what the sensors and/or ecu can "measure" and the actual afr at WOT is actually quite a bit lower. It has to be. Even if the 12.08 is the somehow lowest afr the car could achieve despite the targets, no way it would hold a steady 12.08:1 ratio throughout the entire rpm range.

As far as my ocd is concerned, as long as the numbers are accurate between 12.08 and 18.12, its ok. I obviously want to keep well within that range anyway. Hopefully,
my next tune leans the car up a bit.

I can't stop looking at your data. I think what's interesting about this one is your commanded air/fuel ratio at wide open throttle (WOT). Why does the commanded air/fuel ratio get richer and richer and then jumps back up and get richer and richer again? I mean, it's seeing something else besides the air/fuel ratio to command it to keep getting richer since the air/fuel ratio stops at 12.08:1. It has to be going off of the O2 sensor or a combination of things to decide to keep going richer. It's like it knows you need more fuel despite showing the air/fuel ratio stopping at 12.08:1. It keeps commanding more fuel all the way down to 10.0:1 or so. I am assuming it is starting leaner at the beginning of the rpm band and getting richer as the engine goes through the rpm band.

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post #25 of 33 Old 06-25-2017, 12:36 PM Thread Starter
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Originally Posted by Myxalplyx View Post
I can't stop looking at your data. I think what's interesting about this one is your commanded air/fuel ratio at wide open throttle (WOT). Why does the commanded air/fuel ratio get richer and richer and then jumps back up and get richer and richer again? I mean, it's seeing something else besides the air/fuel ratio to command it to keep getting richer since the air/fuel ratio stops at 12.08:1. It has to be going off of the O2 sensor or a combination of things to decide to keep going richer. It's like it knows you need more fuel despite showing the air/fuel ratio stopping at 12.08:1. It keeps commanding more fuel all the way down to 10.0:1 or so. I am assuming it is starting leaner at the beginning of the rpm band and getting richer as the engine goes through the rpm band.
Well, according to DannoXYZ, "Typically mid-range RPM AFR is leaner for quicker-response and torque. Getting richer in the upper-RPMs for safety."

OVT also mentioned about not raising the afr too high for safety reasons. I'm sure he was worried about heat and pre-detonation at high rpm. But you raced your Rav4 for years with a much more stoiciometric afr at wot with no problems. With stock manifolds and cats even. Though obviously tuned differently from the factory, our engines are mechanically the same.

R9k tuned brought your afr a lot lower though. I definitely won't assume to know more than them. What is your commanded afr at wot now? I wonder if they had to lower it to run the more aggressive timing.
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post #26 of 33 Old 06-25-2017, 12:54 PM
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Originally Posted by Moondoggy-X View Post
R9k tuned brought your afr a lot lower though. I definitely won't assume to know more than them. What is your commanded afr at wot now? I wonder if they had to lower it to run the more aggressive timing.
I guess I'll have to make a run tonight somewhere to find out. Any other parameters you interested in? I'll add it to the video screen if it is available for me to add for viewing.

And for the record, anyone reading this thread, I run 92 octane ALL THE TIME. I don't want anyone to assume I'm running intake/exhaust mods like this all year round without knowing this safety measure. I am sure Moondogg does the same. The ignition is more aggressive with running higher octane. I know because I tested it but not sure if I documented it anywhere here. If you have a Weapon R intake, especially with that crappy Weapon R filter, be advised that my air fuel ratios at wide open throttle was stupid/ridiculously lean. Like 14:0.1 - 16.0:1 or so. I believe I did document that when doing dyno runs with it. And gained NO hp over stock intake, using the Weapon R air filter.
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post #27 of 33 Old 06-25-2017, 01:07 PM Thread Starter
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Myxalplyx, i was just watching your Honda Pilot intake comparison video, and i noticed that you pilot measured an afr much lower than 12.08:1. So i did nome googling and saw that it uses a 5-wire o2 sensorn instead of 4 like our toyotas. That lead me to this...

"Different sensor technology. In general:
-- 1 wire sensor is old-school, just a signal wire with the ground coming from the exhaust itself
-- 2 wire sensor added a separate ground wire for a cleaner signal
-- 3 wire sensors added a heater circuit and both the heater and signal share a ground
-- 4 wire sensors have been the norm for a while and you basically have 2 circuits -- 2 wires for the heater, and 2 wires for the signal (adds dedicated ground to the 3 wire)

Recently, there have been more 5-wire sensors which are actually wide-band type sensors (as opposed to a simple "rich/lean" switching sensor). These sensors utilize a pumping current and different control scheme than the "simpler" switching sensors which simply generate a voltage based on O2 content....

Basically, if you've got a 5-wire O2 your car is running a wideband front sensor and you need to replace it with a similar sensor..."
Our o2 sensors are definitely no narrowband since they read 0-5v, but i assume they dond have the sam range as 5-wire air/fuel sensors either. Which further explaind the 12.08min-18.12max readings we get.

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post #28 of 33 Old 06-25-2017, 06:54 PM
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post #29 of 33 Old 06-26-2017, 05:32 PM
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Hmm, certainly looks like some sort of hard limit/edge on the charts for AFR. I wonder if this is car with simulated O2 output that's scaled back up? Some wideband sensors on Toyotas had their outputs scaled down to fit within 0-1v range mandated by OBD-II standards. The scan-tool would scale it back up for display, but you lose range and resolution in the process.

Could also be problem with heater-circuit as that will throw off calibration, but not throw a code. Toyotas use higher-temp 1200-F heater compared to other wideband sensors. May want to check that heater-circuit is drawing 5-7amps. It may still work at the 3-4 amp draw of other sensors, but the numbers may be off.

Another very slim possibility is someone installed an older 4-wire narrowband sensor for the upstream sensor. It's possible since the connectors are similar.
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post #30 of 33 Old 06-26-2017, 06:57 PM
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That could be the case, I know our Snapon scan tools can read the full monty on those O2 sensors AND there's also a pid for the equivalent 0-1 volt scaling as well.
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