October 18, 200718 yr Hey I have this svx with an automatic 4eat in it. My problem is that my svx is an euro style and the transmission is a US one.. those differences makes the centerdiff not engage the way I want. What I want is to have a device to controll this diff manualy with a potmeter or something so that when the road get iced up I can adjust the power to the rear. Now I do know electronics and I can build pretty much whatever I want.. The question is what do I want? Does the solenoid in the diff get a square pattern or a wave pattern signal? How many volts are the signal? If I can get some answers to this I can build a controller to adjust the center diff.
October 18, 200718 yr yes, you can do this, others have. you don't think a simple on/off switch would work? in one of the duty C solenoid switch threads there was discussion about making this exact type of controller you speak of, might be some good information in that thread and someone may have mentioned what type of signal and controller, etc. just for future reference the 4EAT doesn't have a center differential, it uses rear transfer clutches which are affected by duty solenoid C. good luck, hope you pull it off!
October 18, 200718 yr Author yes, you can do this, others have. you don't think a simple on/off switch would work? in one of the duty C solenoid switch threads there was discussion about making this exact type of controller you speak of, might be some good information in that thread and someone may have mentioned what type of signal and controller, etc. just for future reference the 4EAT doesn't have a center differential, it uses rear transfer clutches which are affected by duty solenoid C. good luck, hope you pull it off! Well maby that would work... simple is always better. So if I run a wire to the solenoid and feed it with 12v it should split 50/50 by locking up those transfer clutches? Thanks
October 18, 200718 yr So if I run a wire to the solenoid and feed it with 12v it should split 50/50 by locking up those transfer clutches? close, but actually it's the opposite. cut off power to the duty C solenoid (just one wire) and it locks the transfer clutches. so if you go cut that one wire right now, it will be locked. you'll need to install a switch to complete the circuit for normal driving. a double pole double throw DPDT switch works best, as i also wire in an indicator light so as not to leave it on. actually before winter gets here i'm going to wire it so my hazzards come on, that way i don't accidentally leave it on. in the past i never did, i'm much more forgetful now, i left it on a couple times last year. the small light i had wasn't enough, can't see it during the day really. my XT6 is awesome with this. add the clutch type rear locking diff and my AWD Impreza feels like a RWD truck compared to the XT6 with the duty C switch.
October 18, 200718 yr Hey I have this svx with an automatic 4eat in it. My problem is that my svx is an euro style and the transmission is a US one.. those differences makes the centerdiff not engage the way I want. What I want is to have a device to controll this diff manualy with a potmeter or something so that when the road get iced up I can adjust the power to the rear. Now I do know electronics and I can build pretty much whatever I want.. The question is what do I want? Does the solenoid in the diff get a square pattern or a wave pattern signal? How many volts are the signal? If I can get some answers to this I can build a controller to adjust the center diff. You may not be able to do what you want. You need to further investigate and confirm you have a US transmission. European, Austrailian SVX's have a center diff along with a clutch pack. As far as adjusintg power to the rear (nipper disclaimer here, i dont aprove of it) its going to be either 50/50 or TCU controlled. The Duty C is normally pulsed on/off to control the amount of torque split. The only way you can make it adjustable (and this i would aprove of myself 100% if someone can do it) is to figure out the pulses the TCU sends the clutch pack. Then you need a pulse generator to reproduce that signal on demand. I should have gotten an electronics degree instead of mechanical :-\ nipper
October 18, 200718 yr SHARE !!!!!! the last thing i want is for you to see this thread !!!! i can see it ramping up to a "it's going to blow, you're going to die" thread shortly, just waiting. okay, seriously - he's not very interested in sharing (understatement), so can't do it.
October 18, 200718 yr the last thing i want is for you to see this thread !!!! i can see it ramping up to a "it's going to blow, you're going to die" thread shortly, just waiting. okay, seriously - he's not very interested in sharing (understatement), so can't do it. NO ti wont turn into that. If you look back youll see all along that i have said this is the proper way of doing it so nyahnyahnyahnyah and stop teasing me :-p nipper
October 19, 200718 yr Author I know for sure that I have the us tranny style with the clutch pack. I know this because I put it there.. And yes I have an electronics degree
October 19, 200718 yr if you can find someone with an oscilloscoop and an SVX your problems may be solved might want to contact fadedbear on the subaruxt board, I know he's into electronics
October 19, 200718 yr Did it originally have the vtd rear transfer[planetry gears and clutches]?Most electronically minded people say such things are easy,pot switches adjustable ,use a controller like in radio contolled car etc,but getting one done is another story.A few australian shops have made the centres adjustable but the cost is high.Myself and a few others are very interested in controlling the centre but we are using the vtd centres.Keep us updated on this one.
October 19, 200718 yr I know for sure that I have the us tranny style with the clutch pack. I know this because I put it there..And yes I have an electronics degree i do not have an electronics degree, but my idea was ... instead of controling input to the duty c, control the output from the rear speed sensor. i'm told this is a square wave? and this is the what the computer uses to determine how much power to send to the rear. the single biggest advantage to this would be that even when you have it maxed out with 50/50 power split, you still have the designed 'slip' which would avoid damage to the transfer clutch. i have no idea how to build a square wave generator and as nipper pointed out last time, you have to have some output from the speed sensor or the computer will think it has failed and go into limp? mode. i guess you could rig a small motor to match turn for turn the rear speed sensor and then gear it down and then moutn another sensor sending unit ... or maybe you could do it electrical components and no moving parts. ideally you would have one you could dial in, or one that would send the computer only 80% (or whatever) of what was comming from the sensor. good luck.
October 19, 200718 yr i do not have an electronics degree, but my idea was ... instead of controling input to the duty c, control the output from the rear speed sensor. i'm told this is a square wave? and this is the what the computer uses to determine how much power to send to the rear. the single biggest advantage to this would be that even when you have it maxed out with 50/50 power split, you still have the designed 'slip' which would avoid damage to the transfer clutch. i have no idea how to build a square wave generator and as nipper pointed out last time, you have to have some output from the speed sensor or the computer will think it has failed and go into limp? mode. i guess you could rig a small motor to match turn for turn the rear speed sensor and then gear it down and then moutn another sensor sending unit ... or maybe you could do it electrical components and no moving parts. ideally you would have one you could dial in, or one that would send the computer only 80% (or whatever) of what was comming from the sensor. good luck. I know if there is too great a differnce between the front and rear speed sensors for too long, the TCU thinks that something is broken and will shut down the AWD. Also I dont know how this will affect the spedo, as the two VSS circuits can independently operate the spedo. Just something to think about nipper
October 19, 200718 yr bump. why won't this thread show up on my list/search of 'new posts'? i must have clicked somthing i shouldn't . oh, well.
October 19, 200718 yr Author well I will give this a shot. I do know that the signal has to be square wave. .. Untill I figure this out I will wire in a switch in place of the soon to come pwm
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