vF Tuner for the 3.5L Tacoma

For recognition of writing technique, yes. Everything else it's debatable.

 

I've been itching to dig into this thing for a while now to get rid of the awful laggy throttle, slow free revving, and rev hang that most of us manual owners have been complaining about for over 3 years now. Unfortunately around the time VF came out I got super busy at work and haven't had much free time. But, last weekend I did have a few minutes to spare and figured out the laggy/inconsistent throttle issue, at least for my preferences anyway. What most of us seem to want is just a plain old linear throttle feel, like if it had a throttle cable. Turns out the way to do that is to edit the throttle table so that it's, wait for it...LINEAR! Not sure why even in 2.0 the throttle table is still messed up; maybe there's something Mat knows that I don't, I'm not a professional tuner so that's very likely, but here's what I did and I've been driving on it for a week now with no ill effects so far.

This first screenshot is the original table for 'Acceleration - Primary Throttle Torque Target'. Left to right is the percentage the accelerator is pressed and top to bottom is the current engine speed and each corresponding cell is basically the percentage of throttle the ecu is actually requesting from the engine. So for example if the pedal is pressed 20% and the engine is currently at 1600 rpm then it should actually give you 20% throttle. BUT, if the pedal is pressed 20% and the engine is currently at 4000 rpm then it appears to be requesting -8.25% throttle from the engine. Obviously negative throttle is impossible, but I assume the logic it's using here is that you're already at a fairly high rpm and only pressing the pedal a little bit so you must want to slow the engine down, so lets close the throttle. In reality, we know that if the engine is at a high rpm and the throttle is only opened a little bit, it will slow down naturally anyway, I don't need the computer making it more complicated than it is. If I wanted no throttle, I wouldn't have my foot on the pedal at all. On top of that look closely, there's no 100% even at 100% throttle. What I'm not sure of is maybe it automatically scales itself to the highest value, so 87.5 would become 100% throttle? I don't know.

Long story short, apparently pressing the pedal down a certain amount doesn't actually correspond to the throttle opening that amount, it constantly changes depending on where you are in the rev range which is not at all linear like a cable actuated throttle would be. The end result is a throttle that is impossible to predict and therefore very clunky and inconsistent when trying to blip the throttle between gear changes for example.



So the next shot here is what I did to change that. In my opinion 20% throttle should never mean anything less than 20%; If I wanted no throttle I would take my foot off completely but that should be up to me. So in any given column for accelerator percentage, I made that the minimum torque percentage. That being said, I am ok with the throttle ramping up a little bit quicker just off idle so in the lower rpm areas where the table previously had torque percent values that were higher than accelerator requested percent, I went ahead and left them as is. This is actually not uncommon on cable actuated throttles, whether it be carburetors or a fuel injection throttle body, If you take a look at the cam where the cable attaches it is often times not quite round but a bit eccentric so that the initial pull on the cable opens the throttle just a little bit more quickly than later on.


I've been driving on this for a week now and I'm happy to say the throttle is much more predictable and easier to modulate. I might still change it up some to smooth it out a little more and maybe have it ramp up a little quicker off idle but overall I'm very happy with the outcome. However, this doesn't change the fact that it still revs slowly and still has rev hang; those are things that I imagine will need to be tackled through the fueling and timing tables which I'm going to have to do some more learning before I go too crazy with them. Since it has two different fuel injection systems on top of various other calculations it makes based on all sorts of other factors like cam timing for example, it's quite a bit more complicated than the older Subaru's I cut my teeth on years ago that just had an AFR table and a timing advance table and that pretty much took care of it.

Can't forget the usual disclaimer, this has worked for me but do it at your own risk. I'm just some random guy trying and learning from things I only have a basic understanding of, I'm not a professional and take no responsibility if you blow up your truck


Oh ya one more thing, I mentioned this a while back and haven't seen any changes so maybe OV can chime in. Other tuning software I've used allows you to drag and highlight an entire section of a table and increment the whole area up or down by percentage or by a certain value but there seems to be no way to do that in VF unless I'm missing something? The only way I have been able to modify tables is to double click each cell individually and type in or paste the new value I want there which is very clunky and time consuming.

 

I haven’t played around with the throttle tables or anything yet, just the alternator settings.

Starting to sound like i may need to...

 

I think the thing to understand is that throttle cables worked on shaped cams and lever arms. So while we all talk about linear and cable throttles, it was never really 100% linear.

The TPS, ECU, and the tune tries to interpret that response.

That said, nice work getting it sorted for you.

 

Agreed, even a 'linear' cable throttle isn't usually perfectly linear, the cam on the throttle body generally has some sort of lobe shape to make it open more quickly in one area vs another, but even still pressing the pedal a certain amount used to mean the throttle opening that amount all the time, regardless of what else was going on. So I guess more accurately my complaint with the throttle in this truck has been more about its consistency. I want x amount of pedal to mean x amount of throttle all the time, I don't want to have to guess whether the computer is actually going to give me that this time or not.

 

Dude, as far as the throttle goes, I'm with you 100%. When Mat gets this master key problem sorted and I can register the software, I'll be digging around in the same areas for sure.
Thanks for posting your findings!!
Then all I have to figure out is the damn hesitations in midrange RPM and she's golden!

 

Fascinating stuff. Thanks for exploring and then sharing............................. Frank

 

Not that it matters now, but there was a change to a newer version of the actual flashing software along the way for dongle users.. I think when the files changed from .bin to whatever they became. The old software couldn't flash the new files. The newer software could do both.

Again, it doesn't matter but thought I'd put that in the record..

 

bin files were the OG files before encryption came about and files were read locked starting with 1.05

dongles then went to .pcm
dongleless is .p5f
vF tuner is .vft

PCM flash and toyflash have both had a few updates along the way. I don’t remember all the version numbers (data hoarder @mZiggy probably has all the installers)

toyflash 1.3.2 is the one that can do .p5f and .vft files

 

Toyflash 1.3.2 it is!

 

I’m glad I remember all this super useful information but can’t remember where I put my keys or why I walked into this room

 

The keys are in the freezer for sure.

 

Hahaha, yup.

My memory seems to shit the bed every time I put my glasses down. I have the arm elongation thing when trying to look at stuff up close, so I put the goggles down.

 

@OVTune very interesting stuff

 

That's exactly what we made this program for !!!


When I did linear throttle testing back in the day the folks who reviewed it for me hated it so it never went into a produced tune.

Make sure to check and adjust the 2D throttle limiter tables because those can override this 3D table

 

Wow, they didn't like it? Are they crazy? Am I crazy? Now I'm really curious to hear some more opinions on it if anyone else gives it a shot. Meanwhile I'll just be over here in my own little crazy world, ya'll know where to find me, I'll be the one blipping the throttle and dropping gears for no reason just because I can lol.

I appreciate the heads up, I'm looking for them now but I don't see any 2d throttle tables, are these coming out in the update or am I just looking in the wrong section?

 

Hahaha!

The only something-something that I have played with was @OVTune 's Single Torque Map and the extra granular throttle table. Both are in 2.0. The linear throttle thing must have been before my time.

Over half of our cars have been non-cable throttle. Four of them are MTs. The big deal that I look for is consistency. 2.0 really achieves that.

If I can get some investigating on the 1st Gear DFCO thing, I might try this linear throttle fun.

 

I can't wait to try 2.0VF for AT so I can study the mapping. That's where the real bread and butter will be is fine tuning for your personal preference.

 

Well it was AT folks giving their review ...bleh

 

^enough said lol