STi - Driver's Control Centre Differential

STi - Driver's Control Centre Differential

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vertastic

Original Poster:

81 posts

224 months

Tuesday 24th November 2009
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Morning all.

I've had my 2008 WRX STi hatch for three months now. Its my 5th Impreza in 10 years but the first scooby i've owned with a DCCD.

In the wet I'm locking the diff as I pressume this will give additional grip when cornering but I cant really tell the difference compared to when teh diff is in its normal setting.

Should I be able to notice the difference when cornering hard in the wet..?

Cheers

Stu

Syndrome

892 posts

176 months

Tuesday 24th November 2009
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You'll notice the difference between having it set to open ( 70:30 rear:front torque split) and locked (50:50 torque split). It's not quite so obvious between set to auto and locked, until you have to turn with full steering lock then it will bang and crash like a goodun with the diff locked. I tend to drive with the diff open most of the time, it's essentialy RWD and much more fun. I'll lock the diff if I'm going across a muddy field, and set it to auto on boring motorway trips or short runs.

Edited by Syndrome on Tuesday 24th November 09:20

MilnerR

8,273 posts

260 months

Tuesday 24th November 2009
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Syndrome said:
You'll notice the difference between having it set to open ( 70:30 rear:front torque split) and locked (50:50 torque split). It's not quite so obvious between set to auto and locked, until you have to turn with full steering lock then it will bang and crash like a goodun with the diff locked. I tend to drive with the diff open most of the time, it's essentialy RWD and much more fun. I'll lock the diff if I'm going across a muddy field, and set it to auto on boring motorway trips or short runs.

Edited by Syndrome on Tuesday 24th November 09:20
What he said. The diff-lock is pretty good in snow too, other wise I wouldn't have it locked because of the juddering at low speeds. Lets face it whether the diff is open or locked you're going to have to be going some to make it lose grip on the public road. I've had my STi for 3 years now and I've only had one real moment on the road (standing water + RE070 tyres = brown moment)

scoobyPPP

239 posts

178 months

Tuesday 24th November 2009
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I've heard the dccd in auto is usually the best option, by the way I've have many similar situations with the re70s, can anyone suggest some decent tyres without breaking the bank cheers

94 WRX

68 posts

220 months

Saturday 12th December 2009
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I had a moment on the bridgestones on my blobeye , now running on falken fk452's , much better wet grip and a good price .

94 WRX

68 posts

220 months

Saturday 12th December 2009
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I had a moment on the bridgestones on my blobeye , now running on falken fk452's , much better wet grip and a good price .

stevieb

5,252 posts

269 months

Sunday 13th December 2009
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For tyres, Yoko Parada Spec 2.. Better than the Falkens. But the Bridgestone is not a bad tyre though.

Been out as a passenger in a My04 Sti Spec C, with the RE070 in the winter (Damp Greasy roads), they can grip well in all conditions managed a run from Guildford to Woking in 6 minuts in the wet!

Twilight1

168 posts

180 months

Monday 14th December 2009
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When driving the car hard, different differential locking ratios are making the car act different.

Fully down* (*open) (36:64) it will make the car the most RWD- biased = slower on the corners but it turns well. You will have to steer the front tires more active since wider yaw.

On LOCK (50:50) posistion the front and rear -axles will spin at same ratio. Fastest way around a corner but you have to use more effort turning the car into a corner. Less steering required since smaller yaw.

These conditions only apply on when driving extremely hard but the basics are the same for smaller or easier drive. You may feel some cluncking if more than fully down position is applied, and they are advised only to use on harder conditions (wet, gravel, snow).

Twilight1

168 posts

180 months

Monday 14th December 2009
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Newer STI's like yours have the AUTO- option in the DCCD control and this optimises the settings depending on the condition and various parametres given from certain sensors. So if you want to have the fastest setting, you will either have to choose that are you going to drive the car (MANUAL 36-64 <-> 50:50 LOCKED) or is the car going to help you drive the car (AUTO). You will have to practise what suits you best. In theory the AUTO setting should be the fastest, but you will have to learn and adapt to the way the system works. Basically it will only change the differential ratio depending the the exact moment of vehicle movement. If the car senser that you are going in to the corner and you would need more turn- in, it will add more ratio in to the back. Then when it senser that you've cleared the apex of the corner and you want to start straighten the vehicle, it will add more ratio into the front. Making it faster.

You really should do into somewhere where you could safely practice and start knowing your car better. Its all about physics afterall.

Thank you,
Ville, a Subaru driver from Finland

GravelBen

15,756 posts

232 months

Tuesday 15th December 2009
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There is a video floating around on the interweb of Toshi Arai demonstrating the difference between DCCD settings of an '08 STI on a wet test track, is a bit of fun and quite interesting.

ETA: Found it.

http://www.youtube.com/watch?v=tRrejHG4gl0&fea...

Edited by GravelBen on Tuesday 15th December 06:56

vertastic

Original Poster:

81 posts

224 months

Tuesday 15th December 2009
quotequote all
Thanks for all the help guys.

Have been trying different settings the last few days with all this rain and its clearly more obvious whats what when the road surface is a bit slippery.

Proving a fun car to get used to and quite different from the older scoobs.

Stu

GravelBen

15,756 posts

232 months

Tuesday 15th December 2009
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vertastic said:
...and quite different from the older scoobs.
hehe

Very similar demonstration of DCCD in a Ver.2 STi-RA wink

http://www.youtube.com/watch?v=zHZSgXXC2x8

No auto mode back then though.

Edited by GravelBen on Tuesday 15th December 08:44

vertastic

Original Poster:

81 posts

224 months

Tuesday 15th December 2009
quotequote all
Check out the shoes...!!!

GravelBen

15,756 posts

232 months

Tuesday 15th December 2009
quotequote all
hehe

He just wants to be like Stefan Roser wink

Actually, I seem to recall Senna wearing similar shoes in a video testing the NSX as well.

Maybe I should get some in case they make me a better driver...

scratchchin

Syndrome

892 posts

176 months

Tuesday 15th December 2009
quotequote all
GravelBen said:
hehe

He just wants to be like Stefan Roser wink

Actually, I seem to recall Senna wearing similar shoes in a video testing the NSX as well.

Maybe I should get some in case they make me a better driver...

scratchchin
My favourite shoes for 'spirited' driving are a pair of Patrick Cox leather soled brogues. They let the ball of my foot rotate on the brake so I can do the full heel H&T (nicely demo'd by the jap bloke)whilst alowing a lot of freedom of my foot / ankle, and the soles grip nicely up and down so the foot doesn't come off the brake unexpectedly. There's obviously some thing in it, because that's the third time I've seen that shoe design in a spirited drive video.

JohnSTIwidetrack

1 posts

76 months

Sunday 4th February 2018
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Hi all,
New to the forum and sorry in advance if I'm duplicating a thread. But wondered if anyone knew what the most likely cause of a P1875 (centre differential circuit) code off the DCCD could be?