Tacoma - OVTUNE - VFTUNER - Update Info and Original Development

Not to make this any more confusing... I have larger tires than you (33") and I have had this issue (only happened to me a couple of times though).

 

1.04 “87” Right at 100 miles on this tune. I have noticed several times when at speeds at or below 20 mph while going between a bit of coasting and just a little gas I get a bump sensation. I would describe it as the following.

1. A cheap sprag clutch between the engine and transmission. (I’m really dating myself with this one)

2. The transmission goes into neutral and then when a little power from the engine is detected it drops back into gear under a bit of power/load.

3. There is a lot of lash in the transmission that is taken up all at once.

4. You are gently bumped by the vehicle behind you. (Which did not really happen).

 

I experienced this initially a bit as well but after awhile it went away (like 300-400 miles). In my experience it takes a solid 300+ miles for the tune to fully break in FWIW

 

Still get this to this day, I believe the torque converter has unlocked because of stall speed and then when you apply load it locks/partially locks and gives the jolt. Very annoying with someone in the truck.

 

Alternately, I drive a MT and there seems to be a point in the rpm's between engine breaking and coasting where it feels "loose". At this point in the rpm's, no matter what gear I'm in, I can press the pedal and you feel the "slop" being taken back up abruptly as the truck begins to accelerate again.

 

Off the subject but does Mat have a sticker that can be put on a rear window for instance?

 

I'd put one on mine in a heartbeat if he did!

 

...i was just working on this file for my vinyl cutter when i saw your posts above
making a SPC one as well (they did send a sticker but i lost it)
not a really clean trace due to using a low resolution image.

 

This is concerning...
Hopefully this will be addressed in 1.05

 

Okay- I realize a little off-topic, but since E$Yota brought up changing the diff to 4.88s, I have a stupid question. Since with the new gearing the rear wheel now rotates slower for a given drive shaft speed, what happens when 4WD is engaged? It seems the front propeller shaft and front wheels would try to rotate faster for a given RPM than the rear. What am I missing? Sorry, back to guessing when Mat blesses us with 1.05.

 

You do the front diff too.

 

Thanks- makes perfect sense. I only just hear "Changed my rear diff to 4.88". I'll go look for the right thread now.

 

Yeah this does happen on the autos as well though I think I’ve just learned to modulate the throttle most of the time to minimize any abruptness - but occasionally, like in stopped or slow moving traffic when you need to make a quick lane change or pass someone in a jiffy I’ve had that jolt which I posted about a few weeks ago when my wife almost punched me when I sent her purse flying isn’t an issue day to day but I would agree there can be an abruptness in this scenario

 

You regear the front too man...

 

Quick question for @OVTune or anyone else who knows. Now that Hypertech has released a firmware update for their In-Line Speedometer Calibrator Module (http://www.hypertech-inc.com/vehicle-results.aspx?AAIAID=486254) that allows it to be used in the 2018, I want to buy it. Will this have any effect on how my tune behaves? I assume that it will since it alters the wheel rotation data going to the computer in the truck. Anyone out there using both products?

 

No, I run the Hypertech speedo corrector. Had it before the tune and currently with the tune. The only thing it is manipulating is the incoming signal from the sensor and then recalculates that signal for the needle gauge. If it was before the speed sensor then yes it would make a difference.

 

Thanks! Another question for you (sorry to hijack the thread for a moment here): Does the Hypertech correct the inaccurate gas mileage calculations in the truck due to the larger wheel circumference?

 

Yes

 

Not sure. I get 17.5-18.5 if I drive 75% conservative in mixed driving. 16-16.5 on the interstate going 75-82 MPH. And 16.5-17 driving aggressively mixed driving. I run 4.88s and 33s though. I can check this afternoon via GPS and trip-o-meter...

 

Pending registrations / tune files will be out this week
I will be dissecting toyotas new TSB, and if necessary implement these changes into new files and 1.05 so that it's a default fix in future tunes for people who do not have the tsb flash.