VF tuning collaboration and BS

Are you experiencing the pinging with specific changes? Did you make any adjustments or was the duration of knock negligible?

 

If anyone runs my latest file, please provide feedback on your thoughts / experience.

 

My current tune modified only throttle request to airload, shift schedules, throttle limits, and acis from 2.0. So nothing exotic.

I’m trying to catch it on a log to know whats going on and then hopefully get some guidance from ovtune or the stt club here. It only happens third gear, pedal almost to the floor, 70ish mph. So its hard to grab on a log because I don’t have a lot of opportunities to hit those conditions. I have tried but cannot replicate the pinging in 1st or 2nd gear.

 

Is ignition timing overly advanced in that range?

 

Based on my limited knowledge, that is probably the case. But I need to replicate the scenario with more variables logged to get a better idea of whats going on.

 

I am only speculating... Trying to expand my knowledge as well.

 

I went out to do some more logging with vvt+air load tables and vvt with stock air load tables. Vvt seems to hit target 75 more often with stock air load tables. Also, knock feedback seems to be around -2 under high load low rpm and when vvt is at 75 compared to modified air load I see -4 to -4.5. Klcv is around the same 18; cruising around going up to 21 under high load or heavy acceleration.

Also mpg tanks with air load tables modified. Generally loose 2mpg when they're changed.

 

Modified @dave82at 04A61_Mild+Wild-Stock Regular _Cruise Control_V3.3 tune by adding the Torque 10 table values from PapaRee. I also changed tire size value to 14.4999 for 31" tires (what I run).

Those are the only 2 changes to the tune. It is flashed on my truck now, but new learned values need to stabilize before I can give any specific feedback on it.

One thing I see a lot of discussion about here in this thread is that people feel like they have "hit the wall" with the ability to squeeze more performance out of these "tunes", and I suggest that we are not going to get very far because there are dozens and dozens of tables/parameters that have not yet been defined, or are being intentionally withheld by @OVTune in an effort to keep us from grenading our trucks, or the simple fact that those definitions simply have not been discovered/created yet.

In addition to that, continuing to tune, without having the ability to log wideband 02 and over lay that data against a plot of the MAF is fruitless and dangerous.

In simple terms, unless we can confirm that fuel is tracking throttle and rpm at higher loads, we are pissing in to the wind here.

A wideband 02 sensor, the ability to scale the MAF, along with the injectors to be able to fine tune A/F at all loads/rpms is essential.... Beyond that...It is all guess work.

Ideally, we would scale the maf and injectors, then add timing (and potentially reduce or add fuel) until we are knock limited, then either add fuel to decrease knock or reduce timing to reduce knock once the threshold is determined.

You simply can't do that (effectively) without monitoring wideband 02. Closed loop fueling is determined by the narrowband 02 sensor and open loop fueling determines fuel by using the tables. We have no idea where open loop fueling is without being able to monitor 02 in real time.

Now...my disclaimer.... I do not yet completely understand the logic of the Toyota ECU, so everything I have posted ^ above comes from nearly 15 years of open source tuning my hotrod Turbo Subaru's of which I have 3 now, and have had 5 or 6 over time. The process is pretty much the same with normally aspirated engines, but the pain threshold is significantly lower with our trucks than it is with forced induction engines running on the ragged edge... In Subaru's particularly those without forged pistons, ONE good knock event can end the engine.

In these (normally aspirated) Toyota's one good knock event is just that.... one good knock event. Not saying it isn't relevant or to be ignored, but I am saying that you probably aren't going to break a ring land or shove a rod through the top of the block like you can and often do when cylinder pressures are orders of magnitude higher, like they are in a turbo engine.

 

That's damn good information! So the 2.0 Airload tables really are superior... @Vlady, you were right. Now is there any noticable performance difference between the two?

 

Im going to give this a try, i just changed the last two tune values to 0 as I have catted dump tubes and adjusted the alternator values for an AGM setup. Everything else seems to fit perfectly, 4.88 gears, 32" tires, premium fuel.

 

Please excuse my ignorance, but how does one obtain the wideband o2 sensor necessary for the proper mapping of these fuel maps? Is something like this readily available? If one guy purchases and tunes accordingly, can these values be used on similar ECU IDs or is this now super vehicle specific?

 

If you're up for it try my control and expected airflow tables on the MD Cruiser tune. They are a 2.0 smoothed out. Just lowered the massive humps by 5% and raised the big dips some. They're way more like a 2.0 than Mats smoothing sample tables we've been running.

I feel it's a marked improvement over Mats samples, but haven't compared them to a standard 2.0 table.

 

There's another gent on here trying my Cruiser file with Mats sample air table samples to see if there's a bottom end "punch" missing on mine. I asked him to try because I think me messing with these tables, having a purpose or thought process behind it, clouds the judgement of my own tunes.

 

AEM makes them, so do a number of other people. Generally, they are installed post collector/pre cat and then are wired to a gauge that you mount somewhere in the cab. They all generally come with their own data logging software so you will end up with a .csv file that simply shows time stamp and A/F reading at that particular time stamp. We would also need the ability to interface that data with the data being logged from the trucks ECU which would include the ability to determine the ECU was in open loop fueling mode at the time.

It may be a bridge too far for now, but there may be hope that Matt can figure out a way to allow us to graph open loop fueling against wideband data, so that you can plot the fueling curve against specific cells in the open loop fueling table and RPM+load. In a perfect world, Matt would incorporate the wideband 02 into the logging portion of VFt, so that everything lines up nicely. I can almost guarantee you he has something like that already cooked up for the turbo kits and trucks he's tuning...So getting it in to the normally aspirated set up should not be too hard.

You need to see exactly what cells in the open loop table were engaged at specific moments in time, then compare that to what the wideband 02 reported for that same specific moment in time. In addition to that, you need to be able to see what load and rpm were at that same specific moment in order to determine if the proper amount of fuel requested by the open loop table (cell) was being delivered at that specific moment.

Hopefully that makes sense.

But the underlying issue here is that every one of our trucks is going to be different. My maf scale will be different than yours, or PapaRee's or Dave82at .... Thats why all these guys that are putting cold air intakes on their trucks have no idea what the A/F is in open loop, whether it is dumping fuel (rich) or running too lean. The tables are not dynamic. They are static, and they most likely control injector duty cycle for that specific moment in time. In other words, the injector is only on for milliseconds @ each injection event. Controlling how long that IDC event is, determines fuel for that specific cycle....The injector will spray the same amount of fuel every time that cell is engaged in the open loop fueling table.

In order to make sure that it is spraying the correct amount of fuel for each event, you need a way to monitor 02 in real time.....

It sounds a lot more complicated than it is, but once you are able to calibrate all of that through a combination of scaling the maf, the injectors and the IDC, you can keep the A/F @ stoich or wherever it really needs to be for the best BSFC (brake specific fuel consumption).

Keep in mind, that under high(er) loads, specifically anything other than idle or cruise, the AFR is most likely going to be much richer than stoich.

 

That's what I used.

 

The resulting data you're trying to obtain makes perfect sense. The road to get there is where I get lost... All new to me. Most everything I've done this far has been driveability improvements. Throttle tip in shift points, torque converter lock up... But to truly add some tangible horsepower is above my current pay grade.

 

At then end of the day you end up squeezing little if any horsepower out of it from what Matt has already done. You'd think if there was a way to make more power OVtune would of already done it.

 

Oh good.
Did you feel a lack of "punch" with my tables vs Mats smoothing samples? Is it just in my head? Just right off the line...

 

I would hope there's more to be had as he's dangled a 2.0 "performance" tune in front of us for several months now.... We're just trying to get it in his absence.

 

He either can't, or chooses not to offer it to the public.

My guess, is that he can't because the requisite tables in the ECU have no definitions at this point as I mentioned.

You can increase power in a normally aspirated engine by increasing displacement, compression ratio, adding more air and fuel and increasing timing. You can run race gas and increase the hell out of timing and compression ratio and gain shitloads of power.... Your cat(s) will die violently tho....