HP Tuners for 2005-2015

I think the issue with going too lean under load is pre-ignition and detonation more than power. Even at stoich, not ever single fuel molecule is being burned so going richer doesn't net you any additional chemical energy from combustion.

 

If they are narrow band sensors, which I assume they are, you can pretty much ignore the specific AFR # calculated from the ECU anywhere below probably 13-ish. Narrow band sensors really just tell you if your close or at stoichiometric mixture. Before assuming or changing fueling around I would get a true wide band sensors and controller to see what the AFR actually is. Toyota may be compensating for known error or more likely, unknown error, so they program in some padding. This is typical of electronic fuel injection systems of the OBD-II era but I thought with the CAN bus systems that are common now there would be better control.

 

They are actually wideband stock. The ECU just doesn’t read outside narrow band parameters.

 

If you go into leaner parameters there is a chance that while you may make the same power you may run into knock and pinging under load and acceleration, which is why 12.5 is usually what you want to tune to in order to prevent knock and pinging all the while making the most power you can out of the fuel. You go one point lower for high power engines or high compression ratio engines to compensate for the extra heat being generated inside the combustion chamber. Example, my H/C/I LS2 GTO making over 450HP to the wheels required tuning to around 11.5 AFR under wide open throttle despite being NA due to the big power it was making and the high 11.5/1 compression ratio to prevent knock.. my Tacoma is also right around 11.5 AFR under wide open throttle due to the extra heat being generated by boost despite lower compression to prevent knock. The extra heat generated by the blower requires additional fueling to keep the combustion chamber cool.

Here's a nifty chart which should help.

 

The pre-cat sensors are wideband ratio air fuel sensors.

Various threshold points cause the tune to go into Open Loop.

 

well that is interesting and kind of confusing. Why bother to put a sensor that cost 100%+ more on the vehicle if they don't take advantage of the benefits it offers? AFAIK, narrow band doesn't really have a defined limit. Do you have any more info on the parameters of the stock O2 sensor.

 

??? why use a closed loop/open loop system if there are wideband sensors? Why not just always use a closed loop feedback system?

I've been away from EFI stuff for too long!

 

Because that would be ridiculously over simplified. Duh. Who wants feedback?

 

The ECU software, I presume.

Joking aside, there must be more to why there are wideband sensors upstream of the cat.

Also, is there any data for the accuracy of the stock sensors vs a standalone and calibrated wideband? I have a new Innovate Motorsport WB controller that I bought years ago for a customer project and then he flaked but I kept it assuming it would come in handy eventually. I don't really want to start making new holes in my trucks exhaust but if I get HP tuners hardware I would be all about doing some R&D to find out how well the EFI system does it's job.... i just don't really want to pay for it. Anyone interested in sponsoring me?! :derp:

 

The OEM ones work perfectly fine for tuning all of your engine needs. Your Innovate one is best suited for you to have real-time data acquisition.

 

Is there no real time data logging ability with the factory WB O2 through the ECU via the HP Tuners Software/hardware? It can not be displayed in real time via laptop, tablet, etc?

I did my share of learning and then I feel like I had and still have a very good understanding of modern EFI systems. I know that the previous systems I worked with (both denso ECU from 2000-2007) used NB sensors and were not ideal in closed or open loop under and amount of load, often not hitting targets called for on the maps. The MAF was part of the problem but I can't accept that the stock sensors are good enough without some data or at least first hand experience with specific claims. If the ECU really doesn't monitor the WB sensors outside of the NB range, that is another question mark about why and how this system/logic works.

 

They will display in real time with a laptop, and datalog in real time with the laptop .

 

Example

 

Thank you.

 

Thanks for those replies. Outside of any data or new info, I'll put some data logging on my list to see if I can shed any more light on the stock systems capabilities. Unfortunately it's about #10 on my list. I would love to improve driveability and gain a mpg or two, though.

Thanks again for the info and insight, everyone.

 

The best all around performance, across the RPM band, are the long tube equal length headers.

 

A good tune and or cam gears will net you just that.

 

Looks like my mpvi2 w/pro link arrives tomorrow! I thought my magnuson supercharger was powerful til I regeared with 35's. Need that bullydog tune replaced ASAP with something I can build the truck engine up with. Was looking at a sleeved and built engine but covid happened and made me second guess the investment at this time. I'll see what I can get out of some more bolt ons first I guess instead of all at once.

 

What gear ratio did you go with?

 

4.53 as it's still a daily driver