Need step by step instructions for....

Hey im looking to rig a switch up in my car to lock it in 50/50 as well as keep it in power mode and i was wondering if anybody can hook me up with step by step instructions on how to do that. Thanks.

[Mr. Pockets]

Do you want to do this permanently? Because if you do, your car is going to bind in every turn and most likely chew up the transfer clutch in a matter of days.

If you just wanted to do this for drag racing ( ), then it'd probably be okay if you switched it on and off.

Instructions detailing how to do this are in the FAQ. It's hardly step-by-step, though.

no i want to rig it on a switch so that i can turn in on and off
ive been to the faq site, thats where the inspiration to do so for my car came from but i was hoping that someone has doneit to theres and has some insight for me on it

[UberRoo]

Getting the 50/50 torque split, (which is not technically what you're doing,) is very easy. Duty solenoid "C" is fed a pulsing signal to keep pressure from engaging the clutch. Typically, the signal runs nearly continuously. When the TCU thinks you need more traction, it reduces the number of pulses. If you want to manually reduce the number of pulses, all you need to do is cut the wire that controls the solenoid, which effectively reduces the number to zero.

Under the dash is the TCU. If you look at the picture, there are three plugs going into the TCU. The upper plug (highlighted in red) is the one that goes to the transmission. The green wire with a red stripe controls solenoid C. All you need to do is cut that wire and splice in a switch, which will normally be left ON, but turned OFF to engage the rear wheels manually.

As for the power mode deal, use the stick between the seats. It works pretty well. Somebody on the forums was saying that they just leave it in first and it shifts just past redline. Sounds a little aggressive to me, but that's what the stick is for.

Oh yeah, do this at your own risk! I'm sure I got this all right, but keep the responsibility off my shoulders.

[Subafreak]

When SVX007 (god rest his soul) got his car, it had switches for power mode and FWD. That could only meen the previous owner liked to do FWD burn outs alot to impress the Honda crowd.

[lee]

UberRoo makes a good point about simply leaving the gear selector in 1st. The Subaru EndWrench site says (in one of their PDF files on the 4EAT) that the transmission also sets a more aggressive AWD map when 1st is manually selected, upshifting someplace between 6100 and 6500 to 2nd and 3rd only as needed to prevent damage to the engine.

I'm also pretty sure several of the SVX AutoXers put it in first and just leave it there when they make their runs.

that said, a switch setting the TPS to TCU line as "open" will produce maximum line pressure whenever the throttle is in any position except closed - however, I have no idea what other effects this might induce.

[UberRoo]

Leaving the gear selector is first is purported to invoke a more aggressive AWD map. I have not observed a noticeable change when experimenting with this, but I have noticed a huge increase when manually disconnecting solenoid C.

I have found solenoid C to be slightly lethargic at engaging AWD when at idle. Whenever I lose traction at higher speeds however, it's quite swift at getting things back on track. I think there is simply too little flow at idle to charge the transfer clutch rapidly enough. Having a manual switch would allow you to pre-charge the clutch when you anticipate needing the rear wheels. The more aggressive map probably does not pre-charge the transfer clutch at all, and simply increases it's sensitivity to traction loss, but does not hasten the process in any other way.

As for disconnecting solenoid A, (effectively, the resistor mod,) it will dramatically firm up the shifts, as well as the torque converter lock up. (It's virtually like driving a 5-speed.) I'm not sure why the torque converter lock up would become more firm, as it's controlled by a duty solenoid, but it may be in series with the circuit controlled by solenoid A. It does not seem that solenoid C is in series with solenoid A, but I'm only guessing.

I've never heard of anyone manually setting 'power mode' on a US model car.

[Chiketkd]

UberRoo, since splicing the wire in your TCU controlling solenoid C, did this cause your transfer clutch to be damaged or did you experience any binding in turns? Any long term downsides?

Thanks!

-Chike

[UberRoo]

My transfer clutch broke immediately after I purchased the car, or more likely, was already damaged when I bought it and I just finished it off. (That is to say, it was before I started fooling around with the TCU.)

I don't currently have a switch to operate solenoid C. (Though I will soon.) I extended the wiring harness so that it now passes under my rear seat with plenty of extra slack so that it's easier to work on. (As opposed to crawling under the dash.) I just have a spade connector in the wire, which I can unplug at will.

Yes, there is significant binding in turns - very noticeable. If you left it continuously engaged, you would simply be causing greater wear to all your drive line components. It would probably be relatively little extra wear, but I suppose it would eventually add up over a long period of time. I think the biggest downside is that the binding in turns is annoying, it slightly reduces the turning radius, and it would likely upset the vehicle's handling at higher speeds. (Which is why many AWD road racers run open centre and front differentials, and the mildest rear LSD they can get away with.)

Leaving it engaged all the time would be very much like having a limited slip differential. They do eventually wear out, but because most of the time everything turns at the same speed, it takes a while.