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Guest Legacy777

Tranny resistor, line pressure, tranny life

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Guest meep424

Ok--

 

Thanks for the enlargement link...

 

It runs in parallel with the line pressure solenoid, clearly enough. Assuming that power to that solenoid is limited, the addition of the resistor weakens the "bite" that the solenoid is allowed to have. Therefore removing the resistor creates a stronger pull on the solenoid than before.

 

Only risk:

 

Compare with Chrysler trannies. You know how the minivans are infamous for tranny failure? Well, not ALL of the failures are from a design problem, but a misprint in the books.

 

Chrysler tranny computer monitors the tranny at ~140 samples per second. It pulses the solenoids on and off at very high frequency during shifts to ease fluid in at the correct rate. Well, alot of folks substitute DexIII ATF for the mopar brand, because the manual says you can....

 

But in reality, it's not designed to handle DexIII, which has a higher friction rate to it than the mopar stuff. SO...the clutches grab too soon, the computer compensates by releasing pressure, but then the clutches slip--- on-off-on-off it goes, following that 140hz sample cycle, because something isn't quite right, and the clutches get worn all to heck.

 

Now-- maybe something similar happens to subes when the line pressure changes too much. More maybe the computer is a) better and can compensate or B) isn't quite as picky and no harm done.

 

I don't know myself.

 

But looking at this diagram, I'd say it'd be reasonably safe to change the resistor to something slightly higher, but no more than 25%. If it's really 12.4 ohms, I wouldn't go higher than 15-16.

 

You COULD try to use a speaker L-pad (or wall-mount volume control) that's rated for the highest wattage possible. Mark the 12 ohm point and make sure you didn't ever turn it down less than 12 ohms. But you could then turn it up from there and play with the adjustsability...

 

Meep

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Guest Legacy777

Why wouldn't you want to add a higher ohm resistor then 25%?

 

If you unplug it, you have infinite resistance.

 

I'm tryin to or at least goin to try and pull the amperage so I can figure out the wattage resistor needed.

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Guest Cougar4

Josh,

 

Using the formula P= E(2) /R will give you the wattage. Square the voltage across the resistor and divide by the resistance. Answer will be in watts. As a guess I would it looks to be about a 20 watt size.

 

Nice post on the schematic by the way. It would be nice to see what is in the control box but they don't get that detailed I know.

 

Glen

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Guest Legacy777

Thanks Glen,

 

Yeah I've got all the formulas, just haven't taken readings yet. I will most likely have to splice into the wires and take the readings while the car is driving/shifting.

 

Yeah I would love to know what the ECU is doing when it gets those signals, what logic gates and what not is programmed into it. I'm sure that subaru does not want us to know ;)

 

However it would maybe explain why the tranny is doing what it's doin and not shifting down.

 

I'm still curious about just jumpering the connector. It's not a direct short......

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Guest CipeR

So now can someone post the NON US legacy diagram and we can see how its wired? Then we can get shifts like the rest of the world without any error lights.

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Guest Legacy777

see I saw Mitchell's legacy, and he did have one of these resistor looking thingy's. I don't know if it does the same thing or not. We'd have to find someone either in Japan or down under to scan a wiring diagram for the tranny systems.

 

Mitchell you still around....breathin and such ;)

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Guest Legacy777

hmmmm....don't see one for subies......and the shadetree dudes said it was like 87 bucks.......OUCH!

 

If you find they have them for subies, let us know.

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Guest CipeR

Why dont we just all email them, with such a high response they might think about making one!

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Guest bobjr94

transgo does sell a shift kit for there trannys, is firms up soft shifts,sends more oil the some of the gears that burn up sometimes and comes with a few upgraded parts...its 41$ from the place i get tranny parts but have never tried one....it also fits mazda and nissan cars(mpv,pathfinder,trucks,300zx,etc), since they use the same tranny(without the front diff section)

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Guest Legacy777

Bob.....hmmm wonder how that kit would work....

 

 

Russ, they could go up if someone posts something or edits a thread.

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Guest Bagheera85

Yea.. still alive. Have limited(80) hours here cuz of crappy ISP on base...have been running out of time, and it's $26 for the 80, plus $2/hr thereafter.

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