2016 OVTune Tacoma 3.5L Manual Transmission / Engine ECU Reflash

I would Try some different gas. The closest station to my house is a CITGO but their 93 always makes my truck run like crap regardless of what tune I’m on. Rough idle and stuttering on acceleration.

I’ve been using Kirkland gas from a Costco near me with great results. I will also use a shell station nearby that does 20 cents off premium on Tuesdays. I would Maybe experiment with some different brands or stations in your area and see if it helps.

 

I'm on stock tune and I'm getting the same thing, initially tought it was around 3800-4000 rpm, but after more testing it is at 3500 rpm. The only answer I could find was that it switch from Atkinson to Otto at that point.

 

that's your VVT kicking in. not Atkinson Otto.

 

Isn't the VVT simulating the Atkinson anyway?

 

no comprendo that. it's your timing advance. it's already fully in Otto at that point.

 

These truck are incredibly fussy when it comes to fuel. I just checked and I’ve run 3558 gallons through my truck. Early on I noticed ethanol blends tend to cause the most issues - especially 87e10. I’ve run the 87 tune and I typically still put in higher octane and e0 fuel if I can. The truck is definitely much happier at least in my case.

I’ve also noticed some pretty significant differences in fuel brands. The differences can be staggering, not only in performance but also fuel economy. I’ve seen a 2-4 mpg loss in a few instances just due to fuel.

 

Haven't had the truck for long so my understanding of the engine is not on point lol I am not mechanic either, trying my best to learn more. What I understood was that the engine was not a real Atkinson per se and rather used the VVT to simulate it. Since the Atkinson cycle keeps the admission valve open longer on the compression stroke, it would make sense the Variable Valve Timing would be used for that.

Now I understand the VVT could be responsible for both the Atkinson-Otto switch and the sudden surge of power at the 3500 rpm and that those two events might or might not be related at all. I'm always open to people pointing out my mistakes and correcting them if needed.

I will probably try the 91 MO tune when I can and see if the surge disappears.

 

i don't know all the design details of this motor and I'm not far into this myself. but from my understanding it is two events. Atkinson Otto transition is gradual and lower rpm. I'm not sure of the actual numbers, but probably somewhere around 2k +/- you'll be fully in Otto. then your timing advance kicks in (on the factory time) right around 3500rpm. on the OV tunes the VVT comes more gradually and starts coming below 3500.

the bit i don't know is about the details of the Atkinson Otto transition, and exactly when you're fully into Otto. i wonder if @OVTune can comment?

 

That make sense, but is everyone, tuned or not, experiencing the change at 3500 rpm?

 

My truck surged horribly at 3500 rpm stock. With 1.04r it’s still there but much less noticeable, like whatever causes it is more gradual.

 

i don't know but a big focus of the OV tunes was for driveability, and part of that was smoothing out that VVT transition. the ECU has complex calculations and maps, and requested load is part of calculating that transition, so, because that has been difficult to control, the VVT transition is inconsistent for many who have the tune still. I'm on 1.05 and it's better than ever but can still improve. for factory, from what I've seen here, it's pretty much like an off-on switch at 3500rpm. which is pretty horrible for most of us. we want that to show as early and smoothly as possible.

 

This is exactly what I was expecting the tune would do. I was suppose to get the handheld tuner but Mat got in touch with me and offered me to switch for the cable to get the tune faster. After talking, he told me he didn't have any ECU data for the 2019 and offered me a discount on the cable if I agreed to switch and send him my data.

So far very nice to deal with Mat, and I guess we made a happy guy somewhere because he got a tuner after they went out of stock lol

 

that's great he's helping you. I'm sure you'll be happy in the end... soon hopefully.

 

Are you really surprised with that size of tires and going up hill still!??!!

 

I just got back from just over 100 miles of running around. Highway, city, stop-and-go, 75+ mph.

I was never really a fan of 1.04R; I felt it was worse than 1.04. 1.05 MA 93 is really amazing. I don't have any of the stuttering issues (yet) that others are mentioning. Combining 1.05 with the accumulator delete makes the truck pretty damn nice to drive.

I still feel a slight surge at 3500, but it's nothing abrupt. I'd imagine that it would be pretty tough to dial out completely.
The throttle response is exceptional, and the truck really like to be at 70+ mph. I found myself speeding way too many times today, because I didn't realize how fast I was actually going.

I'm not one to believe the mpg reports that the truck spits out, but it was reporting 20.7 mpg, which would be an all time high for me if it's true. I filled up the tank just before returning home, so we'll see what happens when I hand calculate it after burning through it.

Overall, I'm very pleased with this tune. I doubt I'll be able to resist trying the Otto tune, but for at least the next tank of gas I'm sticking with MA.

 

I've been doing some testing and reading into the shop manual..and believe the 3500 rpm surge is actually from the ACIS. I am working on controlling it further in the ecu

 

With the valves? So at 3500 it's just saying fuck it and blowing them wide open?

 

Section 8
Variable Valve Timing & Acoustic Control Induction Systems
Can you make it sound like a V8 ? Now that would sell the tune all by itself !

 

It's toyotas fancy way of saying intake manifold tumblers, it creates a psuedo variable length intake manifold. How? By keeping a valve closed until a certain rpm and load,

Mazda does this too and it robs us of torque until then open.

 

Ohh, so it’s kind of like how Lexus restricts the intake from opening 100% until really high up in the rpms? So when the intake fully opens it’s something like an instant 50hp gain that hits you like a truck