vF Tuner for the 3.5L Tacoma

TL;DR - the throttle limit per gear tables need to be fixed... and fixing them will mess up your shifting and converter tables. Attn: @dunlap837

Here's why the AT "lugs/bogs/deccelerates" after upshifting and "launches/surges" after downshifting (in most circumstances).

Aggregated below are the "throttle limit normal gear" tables for the stock tune (OVtune non-THX is unchanged from stock; THX is modified but has the same problem). Top line is accelerator pedal %.

Everyone knows the stock tune 'bogs' when it shifts from 3rd to 4th under normal acceleration... Why? Let's say you are gently accelerating from a stop at 13.8% pedal, which gives you 3.3% throttle. The transmission shifts into 2nd where it gives you 4.7% throttle for the same pedal position. Why the change in throttle? You just reduced your wheel torque/leverage by 1.78x after shifting to 2nd. To maintain the same power/acceleration you need 1.78x more torque... and the tune gives it to you. Shifting to 3rd, it gives you still more (7.4%) to compensate for the upshift. Now... shift to 4th... see the problem? Still 7.4%, even though the wheel torque/power is reduced by ~33% (theoretically, with some caveats). You'll now have to press the pedal further (>5%?) to make up for the reduced torque. Repeat for 5th gear. Of course, the opposite happens on a downshift when ascending a grade... more torque/power than you expect.

Now we know how to fix it, in principle; but, what should the numbers be? That's a more difficult question; because... well... a few reasons. You can see some below. If throttle % and torque were linearly correlated (they are not) the "Ideal" numbers below would be what you would want.



You can't go over 100% and you don't want 6.3% throttle at 2.8% pedal in 6th gear. You'll have to make some compromises... but, do keep in mind you'll never need 100% throttle in 6th gear... you may not even need 50%. Same for 5th, etc. You'll want it to downshift before you'd need that much throttle.

It may be desirable to have some up/downshift discontinuity... maybe around 10% or so? If you're forcing a downshift, you probably want more power... conversely, you may be upshifting because you're lifting off and want less power.

Simply raising the shifting points does not address this issue. It's lugging/bogging/deccelerating on the 4th gear upshift, etc. because that is what it is programmed to do.

 

Ok, the time to update my 2017 to the latest ECU is approaching. I see in the ECU update thread that they recommend clearing DTC's, LV's, and AT (which I have an AT so I will) after applying the update. Would it be easier to use vF Tuner to reset/clear those mentioned or will I need to use Techstream? Keep in mind, I have not yet unlocked the ECU ID in vF Tuner, so I'm not sure it will even allow me to do so. I just feel like vF is easier to use over TS.

 

I believe you have to use Techstream for the ECU update.

I personally wouldn't bother resetting AT and LV until after you upgrade to an OV tune.

 

Yes, I'm going to use TS for the update. Navigating TS is a pain and it is much easier to reset everything through vF (in my opinion). I just don't know if vF Tuner locks down that functionality if the ECU is not unlocked.
I'm going to drive the vehicle for about a week or so on the newest update before I do the tune so I'll need to reset the previously mentioned after the update through TS.

 

I believe the resetting, etc. functionality is part of "Flash Manager" not vF. (vF has a shortcut to FM.) If you choose to reset LV... Toyota says idle for 5 minutes with the coolant temp above 176F, IIRC.

The ECU is not locked, you're just using your credits to activate vF editing functionality for that one ECU version.

 

Ooh. Good to know. Thank you!

 

vF does have the functionality, I have done it on my 2020. And when I mean locked, I mean through vF (unable to tune). I will not be unlocking it via credits until a week or so after updating. I have my 2020 tuned and understand the process. I am going to do it to my 2017 after updating the ECU, I just wanted to know if using vF to reset the values is possible before using my credits to unlock the tuning ability. Like I said, TS is not as user friendly or as easy to navigate though and is slow compared to vF on loading times (especially with this newest update the past few weeks).

 

Are your charts taking into consideration the different access values for 4th, 5th and 6th throttle limits?

 

Axis? They are all the same on the files I've looked at.

 

I may have been thinking about the shift maps. Either way, the gray values at the top, the x axis, are different on the shift maps. Meaning they are asking for a certain speed, at a different accelerator angles. This is the only screenshot I have at my disposal at the moment...

 

Yes sir!

 

This really is a brilliant explanation though.

 

Yes, you can flash tunes and reset AT, LV on any year truck with Vftuner’s Flash manager without using credits. You just cannot edit tunes.

 

In the Tune Pack for 3.5 Tacoma, is the tune with THX in the filename just increased throttle response over the same file name just without the THX?

 

There are worse places to be than east Tennessee. Enjoy!

 

Yes. Enhanced throttle response.

 

Lol. I've lived in Louisville for quite a while and liked it, proud to have been a resident here, but it's changed, and after this summer it's about time for me to move on. I've got a lot on Cherokee Lake by Morristown that will be my retirement home in a couple years and I'm looking forward to it. Keeping my truck pristine now but over the next few years it may get a little dirty and scratched finding some good streams to do some fly fishing. Every place has some good and bad, and I think east Tennessee is going to suit me just fine!

 

You can clear values with VF without unlocking that ECU, but I’d highly recommend getting comfortable and somewhat acclimated with TS. It’s a fantastic tool.

 

No, not the shift maps... the "throttle limit normal gear #" maps (and S gears) under Throttle management. The axes are all the same.

But again, if you change the throttle tables you'll drive with the pedal in a different position; so, it'll shift differently.

 

Soooo, what is everyone's favorite @Mooseditty17 tune for 04B04? The one that keeps giving, the latest... so many options.

Our roads are already covered with snow and ice and (-10C) so I think I want to avoid any crazy tip-in. Hoping for better gear holding and power on the highway and mountain hills. My truck loves to shift any any hint of wind or uphill.

The earlier 2.0 betas were the best for me, outside of startup. I'm ready to to try these user tunes!

Cheers to the community.