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Centre Diff Control Use, the real translation!

 
Old Jan 20, 2004 | 04:21 PM
  #91  
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Hey Brian does the wheels Judder when you apply the handbrake slightly when reversing.
Old Jan 20, 2004 | 04:32 PM
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Both front typres are wearing badly on the outer walls.
Is the steeing set up different from a UK Turbo ? , as the Computer system that carries out the 4 wheel allignment only had the UK Turbo listed ?
The STi Type R and RA's have a faster steering rack, but the ideal geometry should be pretty much the same, yes. If the tyres are wearing badly to the outside, then it sounds like they've not set the car up as it should be. Do you have a printout from the alignment session showing the caster, camber and toe angles they left the car with?

One other one, when diff control is fully open in the green, if reversing the car the wheels judder as if the diff lock is on.
Odd, shouldn't be that bad. As SubTypeR suggests, what happens if you try reversing with the handbrake pulled up a little bit, just enough to make the handbrake warning on the dash light up. Does that make the noise/judder change at all?

Is this normal ?
Some of them make strange noises when you reverse, but there shouldn't be any juddering if the diff is fully open, no.
Old Jan 20, 2004 | 04:41 PM
  #93  
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grease monkey,

worth noting that very few type rs and ras had the quick rack. It was by no means standard, only the 22b I think.

I believe it was an option on all others but the current sti 5 type r I am driving certainly does not have a quick rack.
Old Jan 20, 2004 | 04:59 PM
  #94  
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I'll have to disagree there Adam. Type RA's should have a quickrack as standard. Some came with a 15:1 ratio rack, some like mine come with a 13:1 ratio rack as fitted to the 22B. TypeR's dont always have quickracks, i think the Limited versions come with a 15:1 ratio rack though.

Sounds like they gave you a UK spec camber setup, the oficial dealers set the camber up to give positive camber on the front, that is within tolerence! They do this to combat the camber in the road. It doesnt work! LOL

You shouldnt get any judder from the diff if it is fully open (bottom green, not the green with an arrow) and you are reversing, are you sure you dont have a binding brake caliper issue?
Old Jan 21, 2004 | 09:15 PM
  #95  
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My vs 5 has not got a fast rack its the same as a wrx import.

I would really like the whole transmission checked over.
Can anyone reccomed a place to do this.

Who has had many Rs through the door and know the score !

Ive still yet to try the handbrake manuvere as the wife keeps nipping out in the R and im stuck indoors !! Flippin Gyms for ya !
Old Jan 21, 2004 | 09:21 PM
  #96  
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Grease Monkey mate.

i am in the 4 wheel allignment bay tommorrow,

ill post up all the details.

Ill test out the hand brake in reverse to see if it makes any difference to the GRAB the front wheels make.

Like i say when the diff control if Full back into the green on reverse the front wheels are grabing on a not so tight steering lock ?

ill test the 4 wheel allignment tommorrow and see the score.

Cheers all
Old Jan 21, 2004 | 09:47 PM
  #97  
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i am in the 4 wheel allignment bay tommorrow,
ill post up all the details.
The important thing to look for is the camber on the front wheels. As John says above, some places set the cars up with positive camber and this is the last thing you want in handling terms. Look for at least 0.75° negative camber on the front wheels. A degree or a degree and a half will give you even better turn-in, although you may then find the insides of the tyres wearing quicker instead.

Ill test out the hand brake in reverse to see if it makes any difference to the GRAB the front wheels make.
Don't forget you want to lift the lever just enough so the handbrake light on the dash comes on, no more than that.

Like i say when the diff control if Full back into the green on reverse the front wheels are grabing on a not so tight steering lock ?
There are a couple of things that could be causing this. Have you had the front outboard CV joint gaiters checked for cracks or leaks? Is there any juddering when you're turning tightly when the car is moving forwards?

ill test the 4 wheel allignment tommorrow and see the score.
Yeah, let us know what they find.

Old Jan 22, 2004 | 06:51 PM
  #98  
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OK had the wheel wheel alignment carried out and everything is spot on ( it was done 4 months ago as well)

heres the pic of the alignment.



Ive tried the handbrake at low speeds and it frees up the wheels if i have the diff controll in the amber.

But still, when diff controll is back into the green (free) there is front wheel grabbing while reversing, even if i pull the handbrake on the grabbing of a front wheel is the same ?

Theres no wear or cracks on the front gators ??



[Edited by Brian the Sn@il - 1/22/2004 6:53:23 PM]
Old Jan 22, 2004 | 07:08 PM
  #99  
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everything is not spot on. You have diferent cambers at the front, you have out of spec toe on the front, your rear toe is also out of spec.

Red means out of spec, and those values will not give you a well balanced responsive car.

With regard to the front grabbing, i dont think it is transmition related at all. It's most likely a problem with a front brake caliper or a failed wheel bearing. Looking at the cambers on the front you may have one wheel bearing failed if they were once set to be the same.

Post a thread in general technical or suspension as i dont think this is related to the transmition system so is taking the thread off topic.
Old Jan 23, 2004 | 09:30 PM
  #100  
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John, thanks very much. Just got my STI3 and was seriously worried that my centre diff was knackered. But it does exactly as described by everyone else here so sorted

£500 to spend on something else now!
Old Jan 24, 2004 | 02:40 PM
  #101  
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Brian:
Ive tried the handbrake at low speeds and it frees up the wheels if i have the diff controll in the amber.

But still, when diff controll is back into the green (free) there is front wheel grabbing while reversing, even if i pull the handbrake on the grabbing of a front wheel is the same ?
Just so we know exactly what's happening here, are you saying that if you turn the diff control wheel up a bit, then pull the handbrake up as you reverse, all the grabbing and nasty noises disappear, yet, if you back the diff right off, the nasty grabbing remains, even if you pull the handbrake a little?

BTW, follow John's advice and start a separate thread in Suspension, showing that picture you took of the alignment readout. I've got a couple of comments about it but would rather do it elsewhere to avoid taking this thread off-topic.
Old Jul 4, 2004 | 08:02 PM
  #102  
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To resurrect an old but exceedingly helpful thread...

John's provided loads of info on how to use DCCD, as fitted to classic shape cars. The current generation, of course, has DCCD-A, so I'm wondering whether any more is now known about how the -A setting actually behaves. Is it just like running with the diff open most of the time, or does it sense wheelspin (for whatever reason) and start locking up to improve traction?

Also can anyone recommend a way to learn about how it works in a safe environment? Should I book myself onto a track or airfield day, or maybe a road-based advanced driving course like HPC?
Old Jan 18, 2005 | 11:51 AM
  #103  
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Hey thanks for that, all your info helps a lot.


Originally Posted by johnfelstead
How can you ask that after reading the above?

I think you best read it again.

It would be imposible to do half of what it is saying if you didnt adjust it on the move, for example using the handbrake to release the diff lock, then letting the handbrake go to give you back your diff lock setting. It even tells you where you shouldnt adjust it, such as when the wheels are mid air.

You can change the diff setting between fully open and fully locked anytime you like apart from where it warns you not to. If you are going to be doing parking manouvers set it to diff free.
Old Jan 18, 2005 | 12:03 PM
  #104  
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pleasure.

There are now two extra versions of DCCD, the DCCD-A installed on the new age cars upto and including the MY04, and then the DCCD-A for the MY05 model. The main diference between the two DCCD-A's is the inclusion of a yaw sensor on the MY05.

I have a fair bit of info on the upto MY04, but dont have anything on the changes to the programming for the MY05, i suspect its very similar in terms of what is functioning during Manual and Auto mode.
Old Dec 19, 2005 | 12:00 AM
  #105  
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Interesting thread this. Having just purchased an STI 5 Type RA V-Ltd, then it is useful to understand more about the DCCD.
Old Dec 19, 2005 | 07:05 PM
  #106  
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I've just got hold of a Type R..

It's good to read you can adjust on the fly! (as heard a lot of bollox about only adjusting when stationary!)

Must admit I'm still suprised at the aggressiveness of the Type R in full open diff (especially when I step out my wrx wagon and into it )
Old Dec 19, 2005 | 09:57 PM
  #107  
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How strange. Was reading this only earlier too.

Drove a Type R for the first time today and thought I should put it in lock to make it safer. Made the vibrations when I was making tight turn, worried me and the owner but after reading this thankfully its OK.

Just leave it open and enjoy
Old Dec 23, 2005 | 10:49 PM
  #108  
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Heres a Picture of the split ratios i found.

Old Jan 22, 2006 | 01:33 PM
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hi all,lol been looking for information on the the diff settings for months i have a 97 ra,when i put it in full lock and slow down to turn the car just locks on me,when i put it back to normal there is a tump and then im able to move,is this normal.o and any 1 any idea's on a bov for this car,looking to get 1 thats not ur normal pissst sounds,ive heard other 1's that sound like a little bird singing
Old Jan 22, 2006 | 11:30 PM
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Originally Posted by markopolo
hi all,lol been looking for information on the the diff settings for months i have a 97 ra,when i put it in full lock and slow down to turn the car just locks on me,when i put it back to normal there is a tump and then im able to move,is this normal.o and any 1 any idea's on a bov for this car,looking to get 1 thats not ur normal pissst sounds,ive heard other 1's that sound like a little bird singing
what you've described is normal.
Old Jan 23, 2006 | 05:31 PM
  #111  
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ok cheers
Old Feb 3, 2006 | 09:47 PM
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Bought my Type R last night. Everything was fine until I started doing some tight manoeuvring when I got home, then THUMP THUMP. Car not at all happy.

So I went testing tonight to understand and worked out it was fine with the diff open and only gave trouble with the setting on orange. Oh no, what's wrong with my new car?

Quick search on Scoobynet. Found this thread. Now I'm happy again!

Still having problems with the clutch though. Every now and again I get this really big thump and the car jolts. This is as I'm coming off the clutch. And I've almost stalled it a couple of times. I think it's probably because of the lightened flywheel and the aftermarket clutch (Exedy).

Comments?

David

(who now owns Dave O'Brien's Type R)
Old Feb 4, 2006 | 11:29 AM
  #113  
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You shouldnt use lock though just to let you know

Tony
Old Feb 4, 2006 | 01:05 PM
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Originally Posted by TonyBurns
You shouldnt use lock though just to let you know

Tony
Yeah. I know about Lock. I just thought the car would be fine at all the other settings.

I'm running with an open diff now anyway. It seems perfectly predictable on the limit so I'm happy. I guess if it's wet, then put the DCCD a couple of notches forwards for safer driving? (first amber light)

David
Old Feb 5, 2006 | 12:22 AM
  #115  
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Originally Posted by TonyBurns
You shouldnt use lock though just to let you know

Tony
Do you mean for slow speed manoeuvres only and tight hairpin bends?

I find that full lock works very well and instills complete confidence in my RA on fast sweeping bends in the wet - where I wouldn't dream of taking such bends at the same speed with the diff lock fully open!!
Old Feb 6, 2006 | 03:42 PM
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Ive just got a 05 STI with the DCCD-A in it, are the 'free/open' settings the same as above post link, ie 35F-65R or is it different, also does the 'yaw sensor' just ramp the lock tighter if you start sticking the rear end out?

Thanks for any info

Simon
Old Feb 7, 2006 | 09:12 PM
  #117  
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Default diff lock

hi just brought my 1st scooby a sti ra import , i was wondering when its locked u are saying when the handbrake is put on it unlocks it ,i tried this but the light stayed orange shouldent it go green?
Old Feb 7, 2006 | 09:15 PM
  #118  
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Originally Posted by hamyam
hi just brought my 1st scooby a sti ra import , i was wondering when its locked u are saying when the handbrake is put on it unlocks it ,i tried this but the light stayed orange shouldent it go green?
It does work because when it starts to tie itself up, when you are manoeuvring, if you pull the handbrake up, you hear a thud as it unlocks itself. When the handbrake is released, it goes back to what you set it to. I think the handbrake just overules what you set the DCCD to.

I worked it all out in a big empty car park.

Enjoy

David
Old Feb 7, 2006 | 09:18 PM
  #119  
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Indeed, how else could you perform handbrake turns?
Old Feb 7, 2006 | 10:46 PM
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Originally Posted by hamyam
hi just brought my 1st scooby a sti ra import , i was wondering when its locked u are saying when the handbrake is put on it unlocks it ,i tried this but the light stayed orange shouldent it go green?
The orange light doesn't alter position. When the h/brake light comes on the diff goes open. Release the h/brake and the diff returns to it's previous setting.

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