Overland Torque Tune (OTT) by Overland Tailor

My recent road trip over the weekend was flawless thanks to the new OTT. I drove back from the Washington coast with my near 6000lb Tacoma and was able to produce numbers I never thought possible from such a heavy rig.

 

Why does your stock file have an ACIS dip at 3400, but your tune dips at the 3600 range? Is the red line OTT?

 

We couldn't get the tach pickup to work, so we used drum speed to infer RPM. Slight error depending on RPM due to tire size growth. The runs are accurately labeled in the header.

Attached is the log from the run. (Edit) Stock Run log..

 

Well, that should spice up the current tune wars. Competition is good for the consumer as they say. Lots of progression for many of the tuners in the last several weeks.

Well done everyone.

 

I love the education and transparency that you include with your posts. Not just a hyped up, "Aw yeah! Look at them numbers!"

That being said, those numbers sure are looking good!

 

So did the OTT tune for the 3G 3.5L Change from what it was 3 weeks ago? The tune I have from OTT 7.0 Med/Spicy is awesome and previously had the KDMAX Pro (which I did like). The low end torque is noticeable (5th gear 65MPH 1800RPM level highway takes no effort at all REALLY helping MPG), the engine idle feels/sounds stronger, The jerkiness is nearly gone, with an exception of some stop/roll and go traffic but I was informed prior to the tune that my choice of tip in would cause this, shifting is smooth and predictable in 1-4 gears .but I do have an area that I think could be adjusted. I just drove from the beginning of the 110 fwy in the south bay to Sequoia Nat Forrest and back (about 550 miles). During that drive I noticed that freeway driving has fantastic gas mileage(22-23 MPG at about 65 MPH) however the stop and go was (8-10MPG) and of course is understandable. Not to mention I was loaded up with 2 adults, 2 kids and of course all the gear for a 4 day trip.

I love the shifting in 1st to 4th gear and while the TC doesn't do the Lock/Unlock thing in 6th (my KDMAX PRO did this in 6th), it does definatly do it in 5th. The normal operation Trans-Temp during low power is 188 in the pan and 188-200 at the TC. During the rolling hills when I would step on the gas the TC would unlock and kick temps up to 225-230 (about 2100 RPM) at the TC. The only way I was able to get a shift from 5th to 4th was to really mash the pedal or switch to S-mode at which time TC temps would drop much closer to pan temp. So I guess my question here is, Is this expected/designed or am I doing something Incorrect or have incorrect expectations of how it should work. Is it possible to change the build to pop into 4th from 5th faster/easier.

 

Finally a real driving review. Thanks.
I still don't get why these tunes would turn off SLU and heat the tranny up. As you mentioned, you can not even accelerate out of the condition and needed to force a downshift.

 

What's the deal with the dip around 3500 RPM? I see it mentioned above this was caused by the ACIS system (had to google that one). Is there any way to tune this out or otherwise eliminate it? It is quite noticeable.

 

What is SLU? Also If im not mistaken the Trans temp to worry about is 250"

 

It can be tuned out, yes.

 

It can be smoothed out, but it is a compromise. Smoothing it will reduce HP/TQ in what I would consider an important RPM range.

 

Not by a terribly significant margin, and the resulting smooth performance will yield smoother acceleration with an elimination of the bumpy power dips and bumps.

 

Torque Converter lock up solenoid.
A few would tell you 350° is fine. Not for me...

 

OTT also showing SAE Smoothing 0, vs some other data on the site at SAE smoothing 5. The OTT data is more “raw” and other data shown at SAE 0 will show less “smoothing” as well. People need to keep that in mind when looking at dyno data.

 

Smoothing will indeed help to even out some of the larger dips and spikes, but typically can't turn substantial dips into even and smooth power curves. It is very likely that you'll apply an industry standard of 5 smoothing and those same dips will remain nearly identical, particularly as the total curve for the two pulls is nearly perfectly mirrored.

It should be said that it's okay to have that dip I suppose since it appears to be in line with your goals for the tune. you guys made a conscious decision to retain it and have elected to commit to it.

That's not to say though that eliminating it does not have its benefits, or that tuning it out doesn't result in beneficial changes that can be taken advantage of elsewhere.

Your statement is that retention of the dip is done in order to make the most of what you consider to be an important section of the powerband, but by allowing it to remain, the problem is only displaced at best, and over the course of a full wot pull it'll still be noticed and have an impact on performance nonetheless.

If this is the goal for the tune, then well done. If it is not, there's honestly nothing wrong with announcing that it was a disappointing dyno day and that further testing and refinement is being conducted. We've all been there.

I do recommend another dyno day though, at minimum for your own records with proper verification of data and rpm, since inference of rpm's shown is effectively an implied admission of inaccurate and possibly even skewed data.

 

It appears there is a trans fluid high temp error that will happen at 302 degrees coming out of the TC. with 180-220 being the normal range. further reading suggests that 240 can start to have some effect on the fluid with 260 definatly having an effect.

 

I'm guessing he mistyped the number. He was replying to someone who mentioned 250 degrees. Thanks for the info though.

 

If you know you are going to be in driving situations where the trans temp will be increased from normal driving (towing or loaded down going through mountain passes) then I would suggest that you pin the thermostat on the transmission so that fluid is constantly flowing through the trans cooler.

Even on the hottest 95-100*F days in stop/go driving or on the trails, with a pinned tstat my truck never saw more than 180F temps.

 

The issue with tunes that mod TC unlocking tables beyond OEM is that it is turning SLU solenoid OFF and there is no a fluid flow between TC and tranny pan and the cooler.
Pinning the thermostat is useless and won't prevent The temp rise in TC.
Most of the tunes shut off SLU in 3rd, in early stages it was off in 4th on most of tunes. Beware of slow traffic commute.

 

So if that is the case, What does turning off the SLU provide the tune? Do we know what gears in the OTT the SLU is turned off?