GD owners, in what DCCD mode do you drive in?

[Alin]

Owners of 2004-2007 STi's, in what DCCD mode do you normally drive in? Why?

I've been in a habit for years to always put my DCCD in free lock mode right after I turn the car on. I've always felt the car oversteer more in this mode than on auto on really hard turns that I should not be taking on the street. :lol:

I'm not sure how the DCCD works on GR's, GV's, and VA's. If they're similar to the GD's, then what mode do you guys drive in?

 

[Batmobile_Engage]

Free lock mode? I hope you mean dialed to the very bottom, green indicator. Changing DCCD settings can be very useful in certain driving conditions, but it's mostly a fun gimmick. In reality, they could have designed it with two modes, AUTO and FULL LOCK (top yellow setting for loose/off road conditions). I say this because there are a number of different settings people seem to like, that make the car feel faster around a track than auto. That said, when real testing was done with a professional driver, the AUTO setting was faster around the track every...single...time. Mind you, it wasn't a lot faster, merely a half second or so (short track, lots of turns), but the times were quite consistent. I wish I could find that test data. I've tried to find it many times over the last year. The website that had it isn't operating anymore.

 

[Alin]

Yes, green mode all the way at the bottom. I've only used full lock once. I'll look into it when I get home. Sounds like an interesting read.

 

[Batmobile_Engage]

Also, I think a lot of people are confused about what the DCCD actually does. Some seem to believe that it adjusts the division of power between the front and rear wheels. This is not true. The power division between the front and rear wheels is fixed. I believe I understand it properly, but sometimes struggle to explain it. Basically, at the top of the indicator is LOCK and the bottom is OPEN. As a normal differential works, allowing wheels on opposite sides of the vehicle to spin at different rates while cornering, the DCCD allows the front and rear wheels to spin at different rates. Basically, unless we're trying to combat a static traction issue, the only difference you MAY see when changing the DCCD setting is induced over or understeer. The AUTO setting allows the DCCD computer to take into account the myriad of sensors in the vehicle and adjust the center differential to the optimum setting, faster than any human operator could.

I tend to notice that in FULL OPEN (bottom green) setting, I get a little tail happy. Now you must consider how my car's suspension and aero is tuned, so I feel that my tail happy issues in FULL OPEN are at least partially amplified by the way I have the car set up. I don't think most people will notice handling differences as drastically as I do.

 

[Batmobile_Engage]

This doesn't necessarily mean that getting on the gas around a slight turn in FULL OPEN is going to make your oversteer more than in a mode closer to LOCK. What it means is, if you do something to induce oversteer, it will oversteer in FULL OPEN. As you get closer to lock, if you do something to induce oversteer, the rear wheels will not step out as much because they are limited to rotating nearly the same speed as the front wheels, thus keeping the rear wheels in line with the fronts.

Does this make sense to everyone?

FULL LOCK (top yellow) forces the front and rear wheels to spin at the same rate. If you are in full lock on dry pavement, you're going to hear and feel the drivetrain binding during cornering.

 

[Batmobile_Engage]

Personally, I keep my DCCD in AUTO almost constantly. If I do play around with it, I generally put it on the second green indicator from the bottom; one level above FULL OPEN.

Otherwise, the only time I mess with the DCCD is when there is a foot of snow on my street (the city doesn't get around to plow us out until 3-4 days after major snowfalls). Two years ago, there was 16-20" of snow on the street and I had to plow my own way out with the front of the car. I made it down the street in FULL LOCK.

I hope I didn't just screw up this whole thread and confuse everyone. :shock:

 

[Alin]

Made sense to me. There have been times at the very beginning where I used to understeer and it would piss me off. After all the suspension mods, tires, and finnicking around with the DCCD, I have always used free lock (full open). I'd rather oversteer than understeer. I tend to oversteer in a hard turn AFTER I let off the throttle. It's gotta have something to do with the geometry of the load transferred through the car after decceleration.

 

[Batmobile_Engage]

Absolutely. Lift off oversteer is no joke. I experience the same thing. Not to get off topic, but if you can adjust the REBOUND dampening on your rear shocks, make it a little stronger/slower. This will help mitigate that issue a bit by slowing down the expansion of the springs in the rear end that transfers weight forward when you lift off the gas. Because that weight transfer is ultimately what upsets the chassis and reduces traction on the rear tires.

Ultimately, though lift off oversteer seems to be something that you will never really eliminate with the GD STi. It's something you just have to learn to anticipate and counter, or adjust the manner in which you corner to avoid having the issue in the first place. Going balls-to-the-wall down a sweeping on-ramp tends to get me in trouble with lift off oversteer when I finally realize I'm doing 100 and should probably back off. :lol:

A lot of guys I know that track their STIs regularly, swear by the "slow in, fast out" method. They insist that entering too fast and trying to clip the apex perfectly is disaster waiting to happen. Some claim "slow in, fast out" is not the best idea and definitely not the fastest, but the guys I know that hold it as their mantra haven't wrecked their cars yet....so maybe there's something to that. :lol:

 

[War_Panda04]

i always drive in AUTO. the only time i would move it was going around sharp corners sometimes i can feel it binding more that id like it to so that definitely helps it. and using full lock on heavily snowy roads like my unplowed driveway so i can get the snowblower out from behind my car lol. but the settings in the middle i never even used

 

[War_Panda04]

Absolutely. Lift off oversteer is no joke. I experience the same thing. Not to get off topic, but if you can adjust the REBOUND dampening on your rear shocks, make it a little stronger/slower. This will help mitigate that issue a bit by slowing down the expansion of the springs in the rear end that transfers weight forward when you lift off the gas. Because that weight transfer is ultimately what upsets the chassis and reduces traction on the rear tires.

Ultimately, though lift off oversteer seems to be something that you will never really eliminate with the GD STi. It's something you just have to learn to anticipate and counter, or adjust the manner in which you corner to avoid having the issue in the first place. Going balls-to-the-wall down a sweeping on-ramp tends to get me in trouble with lift off oversteer when I finally realize I'm doing 100 and should probably back off. :lol:

A lot of guys I know that track their STIs regularly, swear by the "slow in, fast out" method. They insist that entering too fast and trying to clip the apex perfectly is disaster waiting to happen. Some claim "slow in, fast out" is not the best idea and definitely not the fastest, but the guys I know that hold it as their mantra haven't wrecked their cars yet....so maybe there's something to that. :lol:

on that last part about the "slow in, fast out" im also a believer in that because of the risks involved if you dont hit the apex perfectly. id rather play is safe and smooth than fast and reckless.

 

[Batmobile_Engage]

For shits and giggles, find a *safe* curved section of road that you can test your lift off oversteer issue with. Try it in AUTO, full OPEN and then the lowest yellow icon.

I think you'll be surprised at what the rear end does. Bear in mind, that you might not be able to enter the turn as fast in the yellow setting or you'll understeer right off the road.

Sent from my SM-G925V using Tapatalk

 

[Alin]

"Safe" does not mean highway onramps and offramps like I used to do. :lol: :tup:

 

[Batmobile_Engage]

Well, if you use a little bit of imagination and a lot of good judgement, you'll be fine. Otherwise, look for open track days. There are a few around. There's a track with open days on the west side of Michigan if you can't find anything closer.

To some, it sounds ridiculous to go to a track day just to try this out, but I disagree. If you plan on keeping the car forever, (as I do with mine) there is no replacement for spirited handling experience.

Sent from my SM-G925V using Tapatalk

 

[Grinder34]

The website that had it isn't operating anymore.

Just starting to read this thread, but if you actually know the URL, but it's now down you can use the internet wayback machine:
https://archive.org/web/

It's like google cache on steroids. I used it last month to get a PDF from a now-defunct research organization, and it saved my ass.

 

[Grinder34]

Lift off oversteer can be fun! But if you're getting a bit more than you want, try to soften the rear swaybar one setting. Conversely you can stiffen the front one setting.

Only times I've ever taken it out of "auto" was when I have fun drifting in snowy parking lots. In "auto" it tries to find traction and fights the process of swinging the ass-end around.

 

[Batmobile_Engage]

"Best Motoring" Japan's premier automotive magazine and DVD series did a verrrrrry similar test back in the day as well. I'm looking around again. I'll let you guys know what I find.