DAC = Lame

[G.I.G.]

My girlfriend and I went up to the mountains this past weekend to check out the fall colors and I found myself doing my first 4-wheel'n trip in my 4R, kind of by accident. I didn't go too crazy because I don't have much faith in the OEM Dunflops on my rig and there were no other cars with us.

Anyway, I got to put my 4R through the paces and shifted it into 4-Lo. On our decent I remebered about the downhill assist control button and gave it a try. Man, that was loud and annoying. All it really did was hammer the ABS to keep me under 5 mph, which I guess is what it is designed to do, but it didn't add much value.

Just from past experience, I feel that a good driver can do a much better job on a steep decent using 4-Lo AND the gears (yes, even with an automatic tranny) while using the brakes sparingly. I think that DAC would work better if it downshifted the transmission rather than strickly using the brakes.

I haven't had the chance to use ATRAC yet but I hope it's not as loud and obnoxious as DAC...

 

[tomhaney1]

Designed for those who need it I guess...

 

[G.I.G.]

Designed for those who need it I guess...

True.

 

[tomhaney1]

I have to say that it would be grossly annoying having the ABS kick in like that. I have had one encounter with it on dry pavement and I thought the damn vehicle was going to shake apart!

 

[Northof49]

Just from past experience, I feel that a good driver can do a much better job on a steep decent using 4-Lo AND the gears (yes, even with an automatic tranny) while using the brakes sparingly. I think that DAC would work better if it downshifted the transmission rather than strickly using the brakes.

I agree buuuuuut,

Most drivers suck and have no idea what they're doing, hence ABS, TRAC, ATRAC, VSA, VSC, ESP, DAC, HAC, DSP, ESPNII, etc

 

[tomhaney1]

Re: Re: DAC = Lame

I agree buuuuuut,

Most drivers suck and have no idea what they're doing, hence ABS, TRAC, ATRAC, VSA, VSC, ESP, DAC, HAC, DSP, ESPNII, etc

LOL, Might as well include "The View" in there...

 

[ptung07]

http://toyota-4runner.org/showthread.php?s=&threadid=28933

haha I did the same thing with my friends when going up in the mountains. When heading back down, just for the hell of it I tried the DAC. It worked, but unbelievely loud because of the computer doing the work to brake. However, the system overheated after awhile and just constantly beeped at me until I turned it off. Essentally, it was useless, but I can see some uses for it in the future...maybe

 

[keylay31]

I think the point is for very steep slopes with shifty surfaces (i.e. loose rocks.)

 

[ironadrenaline]

when i went to paragon, and i was going down 70 degree drops, covered in pure ice, it was a god send let me tell you. i probably would have died if i did not have it. trust me when i say it was bad.

 

[rook]

I agree it is a little "clunky". Its too bad the system has not been updated since its inception. I tested the RAV4 system and it is much smoother, you barely notice its action. I was hoping the 4runner would get an updated system after 4 years. We'll have to see if the '08 models are improved.

 

[Koz]

The system was designed for a specific purpose and ironadrenaline experienced it. I too have used it on two occasions where no human could have done what this system did. Also, the other systems have abilities that NO human can do. Take the VSC, I'd like to see how anyone can apply braking to one wheel to keep the ass end from coming around! These features are LIFE-SAVERS!

Koz

 

[jbs]

You definitely want to be in Lo range 1st gear when you use it. If the hill is steep enough to need the brakes to keep the speed down, you should also be using max engine braking.

I used it in 4Lo/D the first time and had the same experience. Using it in 4Lo/1 takes much less braking and it really does a good job assisting the engine braking to keep speed under control without locking up the wheels.

I think it might mention this in the manual.

 

[Koz]

If 1st gear is not used the engine and trans would generate the speed that triggers the brakes. Not using 1st gear/Low would definitely work the $hit out of the system.

Koz

 

[gonzo]

. . . the system overheated after awhile and just constantly beeped at me until I turned it off.

i had the same problem, and that was after only two minutes of use! i have not bothered with it since.

 

[Thai]

i had the same problem, and that was after only two minutes of use! i have not bothered with it since.

Hmm...so, this is interesting...the new Land Cruiser/LX570 can withstand 12 minutes of constant ABS/ATRAC intervention without overheating.

 

[G.I.G.]

I understand that DAC has it's purpose, I just think it is a very limited purpose.

If you were on a steep decent with loose traction, in theory you would have the same results by using the brakes and having the ABS kick in if you lost traction. I think using 4Lo and low on the tranny using the brakes sparingly is still a better option for some of the same reasons stated above. You want to use your brakes as little as possible on long, downhill climbs so you don't overheat them.

On a side note, from what I understand, ATRAC is always on and cannot be turned off. I kind of wish Toyota just put two limited slip diffs on the 4Runner rather than getting rid of the rear limited slip and replacing it with ATRAC. That is the kind of set up that Jeep uses with Quadradrive and it is a great 4-wheel drive system.

Anyway, I should share these pics while I'm at it....

 

[marjnap]

Originally posted by ptung07
. . . the system overheated after awhile and just constantly beeped at me until I turned it off.

I never used the DAC, but I could see it overheating if it uses the brakes. One time my husband didn't realise, since we were rubber necking on vacation down a steep road, that he was riding the brakes on our F-150. Well the brake fluid started to boil from the heat and we lost our brakes, thank god he got it stopped at the bottom of the steep road.
I would of thought it would be like our F-350 with the tow-haul on and use the tranmission to slow itself down on steep downhill grades. I wonder why they didn't have it use the transmission to slow itself down?

 

[Falls]

It is designed for limited situations like stated and works well.

The VSC is wonderful but needs an OFF switch or it can be very dangerous if you try pulling out in traffic on a snow covered road.

The ATRAC is excellent , although another noise maker its great !! (but also needs an OFF switch IMO. )

2 major drawbacks to this truck = no way to turn that stuff off , sometimes you need the go pedal too get out of some situations.

I was under the impression the Jeep Quadradrive system also uses ATRAC (type) and not limited slips in front and rear. ( maybe wrong just what I was told )

G.I.G , excellent pics.

 

[Thai]

I was under the impression the Jeep Quadradrive system also uses ATRAC (type) and not limited slips in front and rear. ( maybe wrong just what I was told )

G.I.G , excellent pics.

GIG is right. QDII uses computer-controlled limited-slip diffs that can "lock up" under limited conditions. See this thread: http://www.toyota-4runner.org/showthread.php?s=&threadid=29192

 

[Falls]

Thats cool , I was unaware , I beg forgiveness.

Now the Jeep has peaked my interest. Is that available in the GC ? I almost bought one of those in 2004 , I think it was a Laredo Sport. I was not sure so I rented one for a week , it had the 4.0L 6 cyl. but I'm sure it was not a quadradrive it was the other selectable system. I must admit that truck/suv was excellent off road even in stock form. It really impressed me with what we took it through.