Quick Change Shift Kit Question

[icingdeath88]

Originally Posted by Trevor

Let it be very clear that when a “QC” is fitted, immediately after more than one third throttle is applied, regardless of any other function, all control of transmission line pressure via the TCU ceases; i.e. the operative signals from the TCU are locked out and maximum line pressure prevails.

What is more, the “QC’ does not in any way act progressively, as has been claimed. The action is complete and immediate. As soon as a set degree of throttle opening has been applied, from that point on, the operative signals from the TCU are immediately, completely locked out, resulting in continuous uncontrolled, maximum line pressure.

As far as progressive vs on-off: I've had the QC on my car for ~1 month now. I'd definitely describe the feel of it as either on or off rather than progressive. Furthermore, there is a quiet click when the QC takes over, which indicates to me that there is a point where something changes. I don't really mind that it doesn't seem progressive though, because generally, I'm either driving hard or I'm driving normal.

[oab_au]

Originally Posted by b3lha

What Harvey does is increase both torque and pressure but not necessarily by the same amount. So it's hard to say whether there is more or less slip during the very short time period of the gear change.

Phil, I think you are just a little bit paranoid about this auto.

This is a strong auto. It is designed to do the job by the manufactures. Members have run 100hp shots of Nitrous, LAN ran 140hp shot, the box handles it just fine, nothing broke, or burnt out.
It is Subaru additions that deviate from the designers intentions.

The shift accumulators are designed to firm-up the clutch/band engagement progressively as the throttle is increased. They are feed from the A solenoid's pilot pressure, so as the throttle goes down and the torque increases the line and accumulator pressures increase, and engagement pressure increases to suit the load.

This is how Jatco designed it to work. It is Subaru's "soft shoe shuffle" change, that turns this action down, so that the A solenoid reduces the line pressure, and if that is not enough, it also prevents the accumulators from increasing the engagement pressure. It is no wonder that there is so much slipping going on, that causes wear and heat.

All the Quick Change does, is to remove Subaru's interference during the change, so that as the throttle is progressively opened, the line pressure, and accumulator pressure, is increased progressively, to suit the throttle opening and load. The way Jatco meant it to work.

The failures that the box had were caused by flaking lining on the torque converters lock-up clutch, that blocked the cooler, so that it lost cooling lube oil flow. The other fault is the very high final drive ratio that they used in the states, coupled with an engine that can pull 4th gear down to 1700 rpm, so that the line pressure got so low the band started to slip and burn.

Harvey.

[oab_au]

Originally Posted by Trevor

Let it be very clear that when a “QC” is fitted, immediately after more than one third throttle is applied, regardless of any other function, all control of transmission line pressure via the TCU ceases; i.e. the operative signals from the TCU are locked out and maximum line pressure prevails.

What is more, the “QC’ does not in any way act progressively, as has been claimed. The action is complete and immediate. As soon as a set degree of throttle opening has been applied, from that point on, the operative signals from the TCU are immediately, completely locked out, resulting in continuous uncontrolled, maximum line pressure.

This can only happen in your mind. It is complete Bull.

Harvey.

[Trevor]

Originally Posted by oab_au

This can only happen in your mind. It is complete Bull.

Harvey.

It is you who delivers excrement. What I have stated is exactly correct. Prove otherwise.

[b3lha]

Originally Posted by oab_au

Phil, I think you are just a little bit paranoid about this auto.

Yeah. You're right Harv. No question about it.

But since joining the SVX community, I've had two transmission failures and spent scary amounts of money having them rebuilt. So I think I've earned the right to be a bit paranoid.

If I could understand how to properly recalibrate the TCU software for better gearbox longevity, it would be installed on all three of my cars the very next day.

[oab_au]

Originally Posted by b3lha

Yeah. You're right Harv. No question about it.

But since joining the SVX community, I've had two transmission failures and spent scary amounts of money having them rebuilt. So I think I've earned the right to be a bit paranoid.

If I could understand how to properly recalibrate the TCU software for better gearbox longevity, it would be installed on all three of my cars the very next day.

Yes
I can understand your caution. I am very glad I bought a 95 model.

Phil I reckon if we work together, this could all be done in the soft wear.

Harvey.

[oab_au]

Originally Posted by icingdeath88

As far as progressive vs on-off: I've had the QC on my car for ~1 month now. I'd definitely describe the feel of it as either on or off rather than progressive. Furthermore, there is a quiet click when the QC takes over, which indicates to me that there is a point where something changes. I don't really mind that it doesn't seem progressive though, because generally, I'm either driving hard or I'm driving normal.

Trevor's argument lies in the use of the word "progressive".
I first used the word in the thread that he started, before the QC was released, here in May 2008.
http://www.subaru-svx.net/forum/show...=44706&page=11

When I said:

The other thing that the SCSK can't do, that the Quick Change achieves is that because the Pilot pressure that the A solenoid regulates, is also used to set the pressure behind the shift accumulators, by keeping this pressure from reducing, it reduces any chance of slip due to the longer engagement time, that the softer accumulator gives, so its action is set in line with the throttle pressure as the whole operation is.
The Quick Changes action is progressive to the throttle position, no change at all on a light throttle, progressively getting firmer with the throttle position.

This is the same as I have stated in this thread, but as Trevor has no knowledge of the workings of the gearbox hydraulics, he could not understand what I said, so he took this word and used it in the context of his own statement, "that it was the QC circuitry that was not progressive."

This is not so. the unit turns on at about 2Volts, and stays that way till it reduces to about 1.7Volts, when it turns off. It has to be this way as the same control port is used for some other things like, low pressure for cranking the engine, and reduces the pressure for low oil temperature.

You can feel the progressive action if you do a 1st to 2nd change on half throttle, then do the same on 3/4 throttle, then again on full throttle. You will feel that the engagement pressure, or the "shift firmness" becomes progressively firmer.

Harvey.

[Trevor]

Originally Posted by oab_au

All the Quick Change does, is to remove Subaru's interference during the change, so that as the throttle is progressively opened, the line pressure, and accumulator pressure, is increased progressively, to suit the throttle opening and load.
Harvey.

What you state is absolutely impossible and is in every sense wrong.

Immediately throttle opening exceeds a set point at quarter to third of travel, the “QC” relay operates instantaneously, all control of line pressure is illuminated and solenoid “A” remains closed, resulting in maximum line pressure. The action is sudden immediate and complete. Nothing is in any way progressive. There is absolutely no way pressure is or can be, “increased progressively to suit the throttle opening and load” after the “QC” has operated..

Your next side step will be to claim that is spite of your wrong statement regarding the “QC”, opening the throttle will increase engine speed, and as a result transmission pump speed, which will in turn increase line pressure.

Maximum line pressure is controlled, limited and set by the pilot valve, which regulates the pressure within the pilot feedback loop. This pressure will be reached at a relatively low speeds, in order to ensure an adequate overall maximum, with this to be further reduced as a means of control utilising solenoid "A".

I appreciate that the application of feed back within a control system is beyond your understanding, but without this included hydraulic control circuit, pressure would run away completely at high speeds. (*Refer below to learn in regard the application of a feedback loop.)

N.B. Therefore all control resulting from throttle opening is dependent on the control signal delivered to solenoid “A”, and which the “QC” instantly interrupts and prevents after application of part throttle. Your thoery is impossible.

The second side step will be to claim that after the "QC" acts, solenoid “A” continues to be controlled via the resistor circuit. The reduced voltage delivered by this circuit is insufficient to actuate the solenoid, and is limited to a holding function after the solenoid has been fully actuated, via the main full voltage signal.

Once the full voltage signal is cut by the “QC”, the resistor signal can have absolutely no effect. Solenoid “A” is isolated from the TCU and any form of control is impossible. Again your thoery is impossible.

What I state is fact, based on common sense and logic, as well as practical oscilloscope measurements, with an SVX both static and mobile, as has been carried out by both Phil and myself.

What you claim is illogical and is impossible. You should study and join this site. ---

http://www.alaska.net/~clund/e_djubl...rthsociety.htm

* The answer to this difficult problem utilised within process control equipment, is to provide a feedback loop, established via a feedback signal, whereby control can be balanced/adjusted, even though variables exist. In its simplest form feedback sensing can be down stream, but when this can not be arranged, sensing can be achieved directly from the controlling device.

[Trevor]

Originally Posted by oab_au

This is not so. the unit turns on at about 2Volts, and stays that way till it reduces to about 1.7Volts, when it turns off. It has to be this way as the same control port is used for some other things like, low pressure for cranking the engine, and reduces the pressure for low oil temperature.
Harvey.

The stupid statements and excuses continue unabated.

I state emphatically that I can understand the written word, as my use of language proves. What is more my correct descriptions of the hydraulics involved, show that I have adequate knowledge in this respect.

By contrast the continual publication of wrong and misleading information is proof of a complete lack of knowledge, intelligence and even common sense

N.B. After the throttle is closed and the TPS delivers approximately 2 volts the "QC" turns ON. At this point all control previously available to solenoid "A", is cut and turned OFF.

There is, and can not be, any form of control during further application of throttle.

When the throttle is closed and TPS voltage falls to 1.7 volts, the "QC" turns OFF, and only then is control of line pressure via solenoid "A" restored.

There is not, and can not be, any form of control during the applicable throttle release.

The "QC" does not, and can not, act progressively. Once the "QC" acts,. no further progressive control is possible.

[oab_au]

As I said before this is all crap. Why don't you go and start an argument some where else.

Harvey.

[Trevor]

Originally Posted by oab_au

As I said before this is all crap. Why don't you go and start an argument some where else.

Harvey.

As anticipated, you again confirm, in a childish state of tantrum, that you do not have the ability, knowledge, intelligence, or intestinal fortitude, to back up any statement you have made.

The fact that you are, and have been altogether wrong, in every respect, therefore remains established beyond dispute. Proof remains recorded. There is no necessity for me to argue elsewhere.

N.B. My signature.

[icingdeath88]

Originally Posted by oab_au

Trevor's argument lies in the use of the word "progressive".
I first used the word in the thread that he started, before the QC was released, here in May 2008.
http://www.subaru-svx.net/forum/show...=44706&page=11

When I said:

This is the same as I have stated in this thread, but as Trevor has no knowledge of the workings of the gearbox hydraulics, he could not understand what I said, so he took this word and used it in the context of his own statement, "that it was the QC circuitry that was not progressive."

This is not so. the unit turns on at about 2Volts, and stays that way till it reduces to about 1.7Volts, when it turns off. It has to be this way as the same control port is used for some other things like, low pressure for cranking the engine, and reduces the pressure for low oil temperature.

You can feel the progressive action if you do a 1st to 2nd change on half throttle, then do the same on 3/4 throttle, then again on full throttle. You will feel that the engagement pressure, or the "shift firmness" becomes progressively firmer.

Harvey.

I'll have to pay very close attention to this the next time I'm driving.

[b3lha]

We already had the "progressive" discussion on Budfreak's forum. Do we really have to do it here as well? Give the mods a break.

A few weeks ago I posted some oscilloscope traces showing the signal that drives the A solenoid. It turns out that the solenoid doesn't work the way I thought it did. At present, I don't really understand how it works. From reading the discussion later in the thread, I do not believe that Harvey or Trevor fully understand it either. At least not in the sort of detail that I would want to understand it in order to mod it.

I was hoping to be able to tune the solenoid A maps in the TCU to get the QC effect that people seem to like. But until I understand it fully, I'm leaving it well alone. It's not worth the cost of another rebuild to figure this out by trial and error.

[Trevor]

Originally Posted by b3lha

We already had the "progressive" discussion on Budfreak's forum. Do we really have to do it here as well? Give the mods a break.

A few weeks ago I posted some oscilloscope traces showing the signal that drives the A solenoid. It turns out that the solenoid doesn't work the way I thought it did. At present, I don't really understand how it works. From reading the discussion later in the thread, I do not believe that Harvey or Trevor fully understand it either. At least not in the sort of detail that I would want to understand it in order to mod it.

I was hoping to be able to tune the solenoid A maps in the TCU to get the QC effect that people seem to like. But until I understand it fully, I'm leaving it well alone. It's not worth the cost of another rebuild to figure this out by trial and error.

I am confident that I fully understand and have correctly described the pulse width modulation of solenoid "A".

However the make up of the PWM signal, which will be the result of computing various inputs remains to be finalised. Phil is the expert here and and his ongoing research, will no doubt provide this detail. This research involves a great deal of time and effort and we are lucky to have his professional services.