BEACH SAND TEST OF TRACTION CONTROLS

4th of July 2011 weekend, 20 miles south of San Felipe, Baja California, Mexico...

Deep sand (bottomless some call it), coarse and fine grain mixed with crushed sea shells.

Steep beach, as well.

4WD alone will get stuck with tires at street pressure... low range, lockers, etc. only make things worse (on this beach).

The only improvement comes from lowering the air pressure about 50% of normal... 32 psi to 16 psi, for example. Street or All terrain, P rated, 2 ply sidewall tires do better than Mud/snow, heavier, 3 ply sidewall tires... which will require even more air removed to gain 'floatation'.

I am running Hankook Dynapro ATm, P rated tires... normally inflated to 37 psi. Upon arriving at the beach, I drove across the dry sand and went until the truck began to struggle... then lowered all 4 tires to 18 psi... and drove on easily, the rest of our time on that beach.

This photo taken the next day is the deep tracks I made before deflating:



See the tire at 18 psi not digging in, but floating on top (note track on left, above):





Driving on wet sand after the tide goes down from the high point can be easier, as well.



However, with the right amount of air removed, driving on deep, dry sand is not a problem... Here, I backed up to our sun shade...



THE TEST... Driving down to the water's edge and pointing my truck UPhill on a steep slope of sand, I tried various selections of 2WD, 4WD, TRAC, LOCKER and A-TRAC to compare the traction (or maybe better 'floatation' up the beach. The truck was empty and tires at 18 psi...

2WD VSC OFF, TRAC, and AUTO LSD all failed to move me more than a couple of feet... of interest, all three modes spun both back tires equally... Which means the sand was uniform under the truck.

If one side was firmer than the other, we would see the open differential mode (VSC OFF) spin the tire on the loose sand and the limited slip modes dig in on the firmer sand and not spin much on the loose side.

4WD HIGH: VSC OFF and TRAC modes BOTH did well, in this short sand climb... I could tell no difference between them (at 18 psi).

On another beach, I could drive with the tires at street pressure using the TRAC limited slip syatem. As soon as I turned it off and went to open differentails, I dug in (one tire in front and one in the rear spinning)... A-TRAC drove the stuck truck out, without deflating.

4WD LOW: Truck dug in a bit... had to feather the gas to climb the beach.

4WD LOW + REAR LOCKER: Suprisingly WORSE than open differentials in L4. Truck wanted to dig in, even with gas pedal lightly depressed.

Drove around and this time engaged the A-TRAC device... the truck climbed up the steep beach and did not dig in at all.

It did as well as the tests in H4... Low range engine torque tends to dig in with excess power. On the beach sand, it isn't power that gets you through, it is floatation from low aired tires.. and easy on the gas.

In this photo I took looking down over my tracks, the deep torn up track is with the rear locker on... and the tracks just to the left of them is using A-TRAC instead of the locker... (the H4 tracks looked the same as the A-TRAC test):



It was more of a surprise for me to see how bad the rear locker did than it was to (again) witness how good the A-TRAC is.

The A-TRAC continues to impress me as the greatest advance in Toyota traction systems to date. Just making all four tires rotate the same (front and rear lockers) isn't always the best way to get over something... A-TRAC senses the rotation speed of all 4 tires and prevents spinning that would sink you or stall you by transfering power to the best tires to keep you moving. Because your differentials are open when there is no need to transfer power/ match rotation (no spinning tires), steering is unaffected... makes the A-TRAC 'golden' for tough trails.

 

very nice! thanks for the review

i will say this though, most of these kids on here don't appreciate, have a clue or both regarding a-trac and or all the combinations can one can play with out in the wild. more concerned about satoshi grills and iphone hookup...

 

this is exactly the terrain I encounter when i head to El golfo de santa clara. I dont go as often now because of my lack of 4x4.
But that terrain changes with the temperature, and when the temps are up, its the toughest.
Glad the truck did great, and the dynapro's are impressing me with each trip you take.

 

You would probably be ok if you deflated your tires a bit?

 

You go to some very cool areas, david.

 

Cool review, cool trip. Cool pics. Thanks for sharing........

 

You're welcome! Did you guys see the trip report and all the other photos, posted here?: http://www.tacomaworld.com/forum/travel/165617-freaky-fourth-2011-baja-california.html

 

It does help tremendously, but my LT load range E tires don't "fatten up" as much as Davids P rated tires when deflated to <20 psi.

 

How about 4 high with the locker?

 

ATRAC FTW

 

Keeping my Taco stock, pretty much to show that a showroom Tacoma Off Road can go anywhere... Just tires replaced with 1/2" taller, the light bar, and the differential breather mod done.

The rear locker only works in LOW RANGE, unless you do the mod allowing rear locker anytime. As far as what would happen, pretty much close to the same... for the reasons I mentioned in my post... A locked differential does not prevent spinning, it just spins both tires the same... instead of just one tire per axle..,. if the terrain allows.

Next time I go to Baja, I will do a more detailed comparison... taking a photo of the tracks after each drive mode was used.

 

I KNOW.

 

You are the one who asked...

Originally Posted by TacoTaro
How about 4 high with the locker?

 

Hi New member. Just bought 2011 tacoma sr5. I was reading about yellow wire mod working on 2009 and 2010 tacoma's. Wondering if it will work on 2011.
Thanks guys awesome sight fun, technical, and interesting.

 

It is the same... there are new replies in the '4-lo trac' thread as well.

 

Anyone on the Gulf of Mexico Coast or Atlantic Coast do any testing in their sand to compare to the upper Gulf Of California (Sea of Cortez) sand?

 

Bump... it's been awhile since we had much discussion on the benefits of limited slip traction controls, etc. We still need some more input from the 2013 system owners, where it seems they added a lite limited slip in H4 (TRAC) with the renaming of the previous strong limited slip from 'TRAC' to 'AUTO LSD', as it is in H2, and makes more sense in H4. 2009-2012 TRAC is different in H4 than it is in H2... ie. TRAC in H4 is like AUTO LSD in H2 (no engine regulation)!