Modified Shft Kit
 

This past week I received my "Shfit Kit" from Small Car Performance. Nice idea, but I thought I could make it a little better. One of my main concerns was that the electronics was exposed to the elements of the engine compartment, I.E. condensation, moisture, or just getting exposed to water. Took a little experimenting, and I had to go to my local Radio Shack & Hobby Store to get everything you see here. As you can see my "Black Box" protects the electronics of the Shift Kit. I also re-directed the vaccum hose so that it points directly from front to rear. Instead of the hose having to try to come around in a bend. The pictures you see here ( More pictures in my locker) represents a " Trial Run" I do not want to install it just yet, due to my transmission is still under warrenty from Subaru, I have a couple of more months to go till it expires. But as you can see it fits in the engine compartment of the SVX with no problems. I drilled all the holes where the orginal "L" bracket is attached to. The wires are only for representation purposes to show you how I would route the wires. The wireing directions is the same as described by Small Car Performance web site. I just made my own plastic housing so I can protect the Shift Kit from the elements and at the same time make it look like Subaru factory OEM part. When I get time, I will provide instructions on how to make your own with part numbers from Radio Shack and the right size screws, washers, locking nuts you will need from your local Hobby Store. Well hope all you SVX owners like my idea.

Enjoy :) :)

More Pics of Modified Shift Kit
 

Locker Link:

http://www.subaru-svx.net/photos/user.php?awdsvx|19947



:)

Very proffesional looking, nice clean install. As a shift kit is my next scheduled mod, after exhaust repair, I'll definately keep this in mind.

Very nice clean install there!

-Chike

P.S. If I ever get a shift kit I may look into doing that. For now, I'm pretty happy with my disconnected resistor firming up my shifts.

Did you ever complete your installation in the black box? If so, did you run into any problems or come up with any new ideas?

I assume you used the Radio Shack "Project Box", part no. 270-383.

I just picked up my Shift Kit and I want to duplicate your installation. Thanks for the idea! :D

I know the upshift is nice and firm, but what about down, does it slam into gear when going down? and is it nice about decel?

Transmission Resistor
 

Reports indicate that some are not happy after taking the transmission resistor out of circuit, due to unacceptably hard shifting, while others find the shifting to be in order. The latter it would appear, may have been experiencing overly sloppy shifting before disconnecting the resistor, hence there was an indication of an inherent fault. In this event, the fault could be in the form of leaking "A" solenoid seat, resulting in faulty control of line pressure and the fix therefore a suspect band aid.

The same, but to a lesser degree, could apply in respect of using the shift kit, so that again caution is called for.

In such an instances the shifts may have been firmed up, but line pressure could remain suspect and ultimately the end result will be costly. Correct diagnosis could have called for only the replacement of the "A" solenoid valve. I put this forward in the hope that the suggestion is timely and may save someone strife and money. None should panic, but all should be aware and take due care.

In order more fully explain, I again publish what I have previously written for another thread:-


DUTY SOLENOID VALVE "A". This is a pulse width modulated duty solenoid valve, ( Sometimes known as a pulsoid). The device is incorporated in the SVX transmission control system in order to adjust line pressure in the following manner :-

The fluid line is provided with a bleed or bypass via an on/off device, in the form of an electrically operated valve. This solenoid valve is opened and closed repeatedly, in a rhythmical manner by a control current which is turned on and off by the transmission control unit (TCU) at a very fast rate. The valve is a normally closed device, and remains closed in the event of the loss off a control current.

After passing through this modulated solenoid valve, the continually interrupted pressure is in the form of a pulsed flow. When the peaks level off with the troughs, there is a resulting overall steady reduced pressure. The level of this pressure is adjusted by varying the on/off intervals. Most often the length of the on time is adjusted and the number of on/off pulses per second is kept constant. The usual rate is around 50 cycles per second.

The resulting adjusted output pressure is therefore delivered as a rapidly fluctuating stream. The system incorporates an expansion chamber as a smoothing element, which works as a sort of cushion. This device is usually in the form of a cylinder and piston or diaphragm, backed by a coil spring. In the SVX system the component is described as a Pressure Modifier Accumulator. The high pressure peaks in the stream press the piston outwards and become rounded off, while the low pressure troughs are filled in as a result of the piston moving inwards under spring pressure. The end result is a smoother level of pressure, such that controlled devices are not materially affected.

An increase in the volume of fluid controlled, is achieved by transferring the solenoid regulated pressure, to a pressure modifier valve and a regulator valve.

It should be clear that by “chopping” the fluid supply in an adjustable way, pressure control is achieved economically using a simple poppet type solenoid valve, with few mechanical or electrical complications. However the valve remains in a continuos cycling mode, which imposes rather arduous mechanical stresses.

THE DROPPING RESISTOR CIRCUIT. It will be immediately apparent that a sudden on off cycle tends to cause what could be called a hammering of the valve seat, even though this is largely checked by the viscosity of controlled fluid flow. The dropping resistor introduces a second series of current pulses applied in parallel with the control signal. These shorter pulses are applied during the off cycles and timed to check the travel of the armature as it reaches the closed position, thus reducing both shock and noise. These secondary parallel signals in effect, “round off” the closing period and reduce the closing shock. This arrangement can be made even more sophisticated and configured so as to soften the the opening cycle, as well as the closing of the valve.

It will be appreciated that reducing the resistance in the circuit, or opening the circuit by omitting the dropping resistor, has two outcomes. Firstly the relative electrical off time is increased thus increasing the line pressure and therefore makes shifts more abrupt. Importantly as a second issue, increased shock loads are applied to the valve.

It is a documented fact that the line pressure control solenoid is the first to fail due to having by far the most arduous duty to fulfill. Failure is usually mechanical resulting in the valve seat not closing properly and as a result line pressure is markedly reduced. The end results are drastic, especially in respect of transmission friction surfaces. The fault will not necessarily be registered as a fault code, as the armature of the valve can be in the fully closed position with the problem confined to a worn and faulty valve seat. In the event of an electrical fault, which will register, the valve being normally closed, will fail safe and result in maximum line pressure.

SOLENOID "C". Also a pulse width modulated solenoid valve this device is arranged to adjust control pressure to the centre differential, or alternatively clutch actuating mechanism, according to model. Solenoid C operates along the same lines as solenoid A. However the duty is in no way as arduous as that involving constant control of line pressure and no parallel secondary circuit is incorporated.

There is reason to believe this post to be inaccurate and misleading. Further info can be found in this thread.
http://www.subaru-svx.net/forum/showthread.php?t=35942

Harvey.

Deceit
 

The object of this thread is outright deceit, in a panic effort to defer attention from this thread:-

http://www.subaru-svx.net/forum/show...306#post442306

Harvey,

The following is an extract from the opening post in the thread you have suggested by way of a reference.

Please confirm for members, that your advice can be accepted as exactly correct.

Quote ---”When full throttle is used, the solenoid stays as an open drain, and the pressure is held high. As the throttle is closed the Throttle Duty Cycle current, is increased to reduce the solenoids drain on the Pilot pressure that acts on the Regulator Pressure Modifier valve and Line pressure is reduced.”