4-Grand Power-Band

Really?
Lol, I would think the 4-pot could take revs well.

The 3.5 loves to rev, keeps pulling.

 

Actually the truck IS all over the place for efficiency. That engine is doing a bunch of things.

 

You don't have to tell me that! I've felt it stock and tuned lol. Mat has explained several of the machinations the engine/software goes through to dance on that efficiency/power tightrope. Fortunately, it can be tamed a bit if that's what a person prefers. I've seen a few ppl talking about the "switch" between Atkinson to Otto cycles, but it's not at all like that according to Mat. Valve timing is more continuously variable than say, a VTEC style switch. That surge at 3500 is mainly due to the ACIS system opening up and simulating a change in runner length (something to do with airflow tumble). Mat has done research on this as well. His blogs are a wealth of information that you're not going to find outside of Toyota.

 

I cruise around @ 1500 RPM unless I have to go higher. I just down shift if I need to get going. It's great for MPG.

It's much easier to do this after the new tune because that dead spot at 1500rpm has been removed.

 

Yeah I cruise I-10 between Boerne and fort Stockton often. Truth be told, if I didn’t have a tach and was listening to the radio, I would probably not notice other than the MPG drops to the mid teens.

 

Yeah I do that on back roads as well, basically every day my commute involves a few miles in 6th at ~35mph. Downshift to third if I gotta move out lol.

 

Do you have a link for this? By looking at the current MPG meter , and by going be feel. It seems like the engine will switch to atkinson mode under low load low rpm situations. I can see the MPG meter jump to 30+ MPG under these low load /low rpm situations.

 

I get the stutter / hesitation at sustained high load high, high rpm from the torque converter. Other than that it's pretty unnoticeable.

 

You're going to have to search for it in the main thread and/or the M/T thread (Mat's posts). It's in there.
I suppose you could also watch intake VVT angles in real time with techstream if you were interested..
If you were to catch Mat in the dev thread and ask him about it, I'm pretty sure he'd answer you.

 

Actually, here you go - from the man himself (Post 808, near the bottom - it's a long one):

https://www.tacomaworld.com/threads...velopment-thread.495735/page-41#post-15493937

 

I experienced some surging around 70-75 when the truck was brand new.
It seems to have resolved itself because I never feel it anymore. I also spend a lot of Time @80-83
Or 65 or less. One thing I notice at the higher cruising speed is that wind matters. A tailwind means I am goi g to get to spend a lot of time in6th(auto) a headwind Means I will be locked into 4th most the time.

Like a post above mentioned, I can get superb milage cruising at 35 mph on back roads

It’s a good engine but it’s trying to be everything to everyone.

 

So what I was trying to understand here, is the 2.7L makes almost full torque almost right away according to he chart above? Whereas the 3.5 the torque climbs along with engine speed. (chart below)?

Is that what I’m seeing?

 

Right, just due to the usual factors: overall displacement, cam profiles, breathing efficiency, compression, EFI programming, etc.

 

So the 2.7L actually has way more grunt than the 3.5 early on, but only so much grunt then it taps out?

That’s interesting.

 

I'm over milage. It is what it is at this point, I got shit to do lol. My surge is definitely noticable. It feels like a miss at high rpm. I never did enough research to find out what *exactly* it is.

 

I think you 3.5 guys have us beat all over the RPM range. Other 3.5 dyno graphs plot low rpm torque much higher e.g.

2016 V6 manual, Dynapack dyno, measured at hubs. Maybe the other dyno was with the auto trans?

 

It is.

This is also one of the reasons some of us M/T guys were asking Mat if he could develop a tune wherein the atkinson cycle is used far less. It was dubbed "full otto" version B in the latest release, and you can definitely feel the difference in grunt down low. I don't know if any of Mat's dyno pulls were done with this functionality enabled.

 

Yes, IIRC it was done with an auto. LOL, we M/T guys don't get much attention

 

I have yet to drive or even ride in a 3.5L manual, a rare breed!

 

Mine drives great now, IMO the early calibration (I bought my truck 10/15) was garbage. A few years later, Toyota came out with a greatly improved tune for the 16/17 (04B13) and early 18's (04A71). I have to assume that later '18's and all 19's have this new code, albeit the cal identifier is different each year.