The EXPO TRON Build

im not on facebook, do u have a group text or email for all the runs you do..i want to get in on these

 

Excellent info man, thank you!

Thanks, yea I was determined to go front LT but I think I may stick with this MT and build it up some more including a secondary shock and bumps up front with a shock hoop and bumps in the rear

I actually don't announce these trips very often and definitely not on facebook haha. Usually if I do have a run coming up with an open invite I post em to the AZ Meet and Greet thread here https://www.tundras.com/threads/arizona-meet-greets.6516/

 

Cool picture!

 

Alright gents lets talk A-TRAC It came as a surprise to me not long after I bought the truck that our trucks do in fact have A-Trac. More so because I was used to the 2nd gen tacomas actually having a dedicated button to turn it on. I'd still prefer a damn button, but the question remains, "When does our A-Trac actually start working?" My guess would be in 4LO, but I'm not certain if that is the case or if it can be activated in 4HI with a combo of turning off LSD or traction control...etc.

 

A-Trac is always on by default in the Tundra in every mode - 2WD, 4HI, 4LO

It engages when it senses wheel spin and your RPM are (I think) above 1500 and below 2800. It's definitely not as smooth of an engagement as it is in the Taco, Runner and FJ.

It will possibly make you shit bricks the first time it engages because the Tundra has the RPM setting so high, but it does work. Just not as elegant as the other implementations

 

great pictures as always ! I wanna go visit Telluride someday.

hwo did the Toyo R/T do in the snow/ice ?

 

Awesome post and write up! My family and I love Telluride and the million dollar highway! Doesn't Brown Dog pizza taste amazing?! That funny you took a picture of your Tundra in the same spot I was in one month prior to you. Lol Keep up the great post on your heavily modified Tundra.

 

Interesting, are you sure that's a 2WD function? I thought A-Trac was specifically for the front end while 4WD is engaged?

Thanks man! Not too bad actually! I really cant speak for other tires as I have not driven on ice or in the snow very much, but I survived the million dollar black ice highway so I cant complain haha

Nice! Love the retros man and that is funny its the same spot and angle! Brown Dog was soo damn good, definitely hitting that place sooner next time

 

@TRON

Thanks! I might change out my retro soon. My family and I go to Telluride every year around Christmas time. If you go during the New Years Eve time you can watch the lighting of the torch celebration. They launch fireworks and have hundreds of skiers going down the mountain with red flares. Very cool to see. I also highly suggest you look into the Narrow Gauge Railroad in Durango. It's an amazing experience to ride from Durango to Silveton! If you want to do snow mobiles look up the mountain excursion near Durango. It's through park reserve land and extremely scenic and lot cheaper than other tours. Some of the cliffs your riding next to are hundred of feet down.

Did you hike to the top of the Bridal Veil Falls?

 

how long is the drive for you from TX ?

 

1,000 miles and 16 hours

 

Yessir. A-trac also works on 2wd trucks that don’t have 4 wheel drive. We took a handful of mixed rigs out to Butcher Jones to document it all and had a Toyota Engineer with us. We put all the trucks into cross axle situations with at least one tire in the air to see it all work with the different settings.

Even the 2wd Tundras got across the ditch with two wheels in the air by having A-trac.

The basic finding is that for cross axle and lifted tire situations, it’s best to just leave the truck in its default setting and let it do its thang.

I have to find the videos

 

I had to load a video to youtube - I apparently got lazy and never did this a year ago.

https://youtu.be/WPaJBJQZq5s

 

the key with atrac is letting it work..when in 4lo keep a constant throttle below 2500 rpm and let the wheel slip a little. most people feel the wheel spin and let off the gas since they are just sitting there spinning, but the electronics need a second to work. the truck will sense wheel spin apply brake pressure so power is diverted to the non spinning tire. and both wheels with spin. once i learned how to make the ATRAC work for you, i dont even think about buying lockers. essentially hold the gas at 2400 rpm and let the truck crawl its way up. you cant mash on the gas so the atrac doesnt work in "power out" situations

 

Can someone explain A-Trac to me?
@TRON @KevinK @zackbremer

 

^^look at the post right above yours

 

Oh!! DUHHHHHHHH......

Guess I shoulda opened my eyes while I was reading

 

Yup. Exactly this. We’ve taken a handful of Tundras on John Bull trail in Big Bear and when we passed this group of Jeeps they asked if we were all locked front and rear, or if we used LSDs. “Nope. Open open” as we all crawled by them.

 

wow!
I was always under the assumption that was the Auto LSD feature kicking it.. Physically there is no A-trac button to control on of off then. Also it would be in this type of situation where A-trac would actually kick on. I've gotten the truck sideways in 2wd with stuffings off, I was able to throttle up and hold(no-atrac kicking)
Have you experienced 4L A-trac kicking on? I've had steep uphill situations where I think ALSD would've helped, but I kept 4L and tires spinning. Backing out and getting momentum is what I ended up doing.

 

The A-Trac only works inside a pretty narrow rpm range. If you pedal past it, say in a powerslide in 2wd, you’re above the threshold. The yaw sensor also knows you’re flat and yawing sideways so it won’t throw A-Trac on during a slide.

*edit* I just realized you had settings off in your slide too, that turns off a-trac

I use A-Trac in 4lo almost every time I engage 4lo. It feels funky the first few times, but once you learn to trust it, it’s amazing.

In a slippery (mud, sand, snow) climb, you probably want tire spin and so it’s better to disable traction control (A-Trac will turn off). There’s a chart someplace if I can find it...

 

Ok that makes sense to me now. I was really getting ready to run some stuff with my buddies 15' 4runner and FJ. As I been in both, and those systems are legit.
I'm pretty sure I must've been in the low range RPM to not kick it on. Probably easier to kick it on in an off camber situation?

@TRON sorry for blowing up the thread, but it is actually your fault. You opened up pandora's box.

 

good info guys. Maybe @Bob or @Sean266 can split this portion of the thread and create dedicated ATRAC thread from it. thx

 

what's a build thread w/o getting on discussions like this..
we'll just change thread title to EXPO Tron/ ATRAC on???

 

started post 475

 

I repent for my sins by offering this previously unreleased image of @TRON ...

 

wanted to quote this so people could see it, clearly letting the wheel spin is needed to engage the atrac, but most people who dont know about it would have let off in this situation cus the tire in the air was spinning.

ALSD is different because it doesnt have the speed (rpm) threshold that the atrac does and also doesnt divert the power 100% to the other tire, it splits the power so both wheels spin

 

I welcome the conversation! I did ask it but every bit of info helps and the EXPO TRON thread is a cool place to discuss Perhaps @KevinK can create a new thread and lead with that video This will help out many other I'm sure as A-Trac is definitely not something a dealership will either mention or have too much info on for new owners

 

Tron

I see you have the switch pro. I recently purchased one, where did you tap into for the light and ignition. I have a 16 pro so I'm assuming the wires would be the same color location. Thanks

 

i think he had it installed by sdhq...