Diff lock setting?
18 July 2002, 06:44 PM
#1
Scooby Regular
Thread Starter
Join Date: Jul 2002
Posts: 53
Likes: 0
Received 0 Likes
on
0 Posts
Recently purchased WRX STI RA V Ltd which has diff-lock and inter-cooler water spray.Was informed by dealer that both these items should only be used if being used for track use.Having noticed now that on cornering the rear end does slide out quite easily and looked up on the SIDC web page I am under the impression that I can switch the diff up to 3/4 to bring in the front diff a little more and this should make the rear end more grippy.Can someone put me straight on this point as I am a little ignorant to this as it does also say that by no means should the diff be locked for road use as this can damage transmission!!Also should I have the water-spray on auto or do I not need that on at all.Hoping someone out there can help as I dont want to do any damage.Other than that I must say what a difference this beast is up to my95 turbo what I traded in for this,they really do fly dont they!!!!
18 July 2002, 10:59 PM
#3
Congratulations, these cars are awesome. 
Please use SUL plus an octain booster! 
Your dealer doesnt know what he is talking about!
Here are the english translations for the centre diff control in the manual, followed by a more acurate translation done for me by a guy in Japan.
DRIVER'S CONTROL CENTER DIFF (DCCD)
The intent of this mechanism is to adjust the diff lock ratio of the LSD (limited slip differential) as necessary.
Adjusting the dial to "diff free" (indicator: green, empty square, empty triangle) under normal driving conditions, and "diff lock" (bright orange solid triangle) on gravel, snow, in the rain, is effective (probably means suggested). By setting the diff lock ratio as necessary, depending on the various roads and running conditions, unrivaled driving mobility will be demonstrated.
WARNING!
This is not an all purpose vehicle. DO NOT overestimate its abilities. Please use appropriate discretion and drive at safe speeds where there are sudden braking, sudden turns, sudden curbs, snowy roads, slippery roads, etc.
USING THE CONTROL DIAL
The dial is located next to the handbrake lever, rotating it fully forward is diff free, rotating it fully backward is diff lock. You can continuously change the diff lock ratio using the settings in between.
DIFF FREE: No front and rear LSD (Front to rear power distribution=36:64)
DIFF LOCK: The front and rear have an almost direct connection. (Front to rear power distribution=front/rear load distribution) (Probably means 50:50)
INDICATOR (ON THE METER DISPLAY)
The diff lock ratio is displayed at one of six settings, as it is linked to the control dial. The upper lighted block (orange solid triangle) indicates a greater direct connection.
The true lock ratio can be continuously changed.
ADVICE
* The indicator is the criterion.
* Regardless of what the dial settings are, LOCK will illuminate for one second after the key is turned to the on position.
* At night, while your driving lights are on, the display may appear to go dark for a moment, but this is normal.
CANCELLATION OF DIFFLOCK
Even if the DCCD is set to LOCK (green), by pulling the hand brake lever, it will automatically go to DIFF FREE, moving all power to the rear wheels. (linked to the brake warning light) However, the indicator will not change.
Once you release the hand brake lever, the DCCD will return to its proper setting.
TIGHT CORNER BRAKING PHENOMENON (makes more sense once you read the following)
When the indicator is orange while driving on dry tarmac/asphalt, corners, and even reverse parking, due to the rotational difference between the front and rear wheels, there are cases where heavy vibration and noise may occur during braking.
Though this is not out of the ordinary, and to resolve this "problem", you can simply either set the DCCD to DIFF FREE or pull the hand brake enough so that the brake warning light illuminates.
While you may feel a light "shock" when using the control dial during quick acceleration and tight cornering, due to the movement of the center diff, this is normal.
WARNING!
* DO NOT use the DCCD while any of the wheels are in mid air.
* Set the DCCD to DIFF FREE while the car is stopped.
* Set the DCCD to DIFF FREE while the car is being pulled or towed. The car can only be towed/pulled either by rope or on a rollback. DO NOT pull or tow the car on only its front or rear wheels. Please see page 195 for more information on warnings related to towing.
* ALWAYS set the DCCD to DIFF FREE when using the emergency spare tire. Change or fix the tire as soon as possible.
* When the center diff requires repair (control unit, disconnected wires, shorted wires, voltage issues, etc.) the DCCD reverts back to DIFF FREE and the indicator (at which you last had it set) should flash at 1 second intervals. Please go to your nearest Subaru dealer immediately. Once a problem arises, even if the unit regains power, it will not reset itself until the engine key is set to the off position.
Please use SUL plus an octain booster! Your dealer doesnt know what he is talking about!
Here are the english translations for the centre diff control in the manual, followed by a more acurate translation done for me by a guy in Japan.
DRIVER'S CONTROL CENTER DIFF (DCCD)
The intent of this mechanism is to adjust the diff lock ratio of the LSD (limited slip differential) as necessary.
Adjusting the dial to "diff free" (indicator: green, empty square, empty triangle) under normal driving conditions, and "diff lock" (bright orange solid triangle) on gravel, snow, in the rain, is effective (probably means suggested). By setting the diff lock ratio as necessary, depending on the various roads and running conditions, unrivaled driving mobility will be demonstrated.
WARNING!
This is not an all purpose vehicle. DO NOT overestimate its abilities. Please use appropriate discretion and drive at safe speeds where there are sudden braking, sudden turns, sudden curbs, snowy roads, slippery roads, etc.
USING THE CONTROL DIAL
The dial is located next to the handbrake lever, rotating it fully forward is diff free, rotating it fully backward is diff lock. You can continuously change the diff lock ratio using the settings in between.
DIFF FREE: No front and rear LSD (Front to rear power distribution=36:64)
DIFF LOCK: The front and rear have an almost direct connection. (Front to rear power distribution=front/rear load distribution) (Probably means 50:50)
INDICATOR (ON THE METER DISPLAY)
The diff lock ratio is displayed at one of six settings, as it is linked to the control dial. The upper lighted block (orange solid triangle) indicates a greater direct connection.
The true lock ratio can be continuously changed.
ADVICE
* The indicator is the criterion.
* Regardless of what the dial settings are, LOCK will illuminate for one second after the key is turned to the on position.
* At night, while your driving lights are on, the display may appear to go dark for a moment, but this is normal.
CANCELLATION OF DIFFLOCK
Even if the DCCD is set to LOCK (green), by pulling the hand brake lever, it will automatically go to DIFF FREE, moving all power to the rear wheels. (linked to the brake warning light) However, the indicator will not change.
Once you release the hand brake lever, the DCCD will return to its proper setting.
TIGHT CORNER BRAKING PHENOMENON (makes more sense once you read the following)
When the indicator is orange while driving on dry tarmac/asphalt, corners, and even reverse parking, due to the rotational difference between the front and rear wheels, there are cases where heavy vibration and noise may occur during braking.
Though this is not out of the ordinary, and to resolve this "problem", you can simply either set the DCCD to DIFF FREE or pull the hand brake enough so that the brake warning light illuminates.
While you may feel a light "shock" when using the control dial during quick acceleration and tight cornering, due to the movement of the center diff, this is normal.
WARNING!
* DO NOT use the DCCD while any of the wheels are in mid air.
* Set the DCCD to DIFF FREE while the car is stopped.
* Set the DCCD to DIFF FREE while the car is being pulled or towed. The car can only be towed/pulled either by rope or on a rollback. DO NOT pull or tow the car on only its front or rear wheels. Please see page 195 for more information on warnings related to towing.
* ALWAYS set the DCCD to DIFF FREE when using the emergency spare tire. Change or fix the tire as soon as possible.
* When the center diff requires repair (control unit, disconnected wires, shorted wires, voltage issues, etc.) the DCCD reverts back to DIFF FREE and the indicator (at which you last had it set) should flash at 1 second intervals. Please go to your nearest Subaru dealer immediately. Once a problem arises, even if the unit regains power, it will not reset itself until the engine key is set to the off position.
18 July 2002, 11:14 PM
#4
so basically, you can use the diff in any position you fancy whilst driving on the road. Its best not to use the lock position unless on gravel or snow, but you can use any of the green/orange arrow positions you like on the road. When you are doing parking manouvers put the diff into its open position.
Personally i prefer it fully open, if its chucking it down i may put it forward a couple of notches, but i like RWD cars. Some who prefer AWD run them a couple forward in the dry, but your going to lose more power at the wheels due to increased transmition losses.
The rear diff in these cars is a mechanical rather than viscous one, so when it locks its quite violent, this has been known to catch people out, again, i love it but thats because i grew up with these types of diff on my rally cars.
As to the intercooler sprays. You can run it in auto if you like on the road, you will get about 60 miles before you empty the bottle. It's not really needed unless you want to give it plenty of stick, it helps most on hot days, in winter you dont need it at all really. What auto does is it sprays the water for 5 second spurts based on boost and throttle position. Once you empty the bottle the indicator light on the dash comes on and the light on the auto switch goes off, this is to tell you auto no longer is functioning. It doesnt mean the bottle is fully empty. You have 10 squirts left in the bottle which you can activate by pressing the manual switch. Pressing the manual switch initiates a 5 second spray. Dont press it more than 10 times beacuse then you really are out of water and you will burn the motor out!
Personally i prefer it fully open, if its chucking it down i may put it forward a couple of notches, but i like RWD cars. Some who prefer AWD run them a couple forward in the dry, but your going to lose more power at the wheels due to increased transmition losses.
The rear diff in these cars is a mechanical rather than viscous one, so when it locks its quite violent, this has been known to catch people out, again, i love it but thats because i grew up with these types of diff on my rally cars.
As to the intercooler sprays. You can run it in auto if you like on the road, you will get about 60 miles before you empty the bottle. It's not really needed unless you want to give it plenty of stick, it helps most on hot days, in winter you dont need it at all really. What auto does is it sprays the water for 5 second spurts based on boost and throttle position. Once you empty the bottle the indicator light on the dash comes on and the light on the auto switch goes off, this is to tell you auto no longer is functioning. It doesnt mean the bottle is fully empty. You have 10 squirts left in the bottle which you can activate by pressing the manual switch. Pressing the manual switch initiates a 5 second spray. Dont press it more than 10 times beacuse then you really are out of water and you will burn the motor out!
Thread
Thread Starter
Forum
Replies
Last Post