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#31
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What is happening, is the torque control that is programmed into the ECU taking affect when the TCU tells the ECU that it is going to shift, or when you start from a stop. Changing the TCU will not help this. But, I think that someone posted a how to on dissabling this function when a manual trans is installed. Not sure if it will work for the auto trans, but it might be worth a try.
I dont think its a good idea though. The SVX puts down a lot of torque and with %100 traction, it will be very hard on the front diff, clutch packs, and torque converter. However, there is a trick to keep the TCU in power mode, and it makes the SVX a whole new car, especially with 4.44s
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IT'S 5:00 SOMEWHERE!!! 92 Liquid Silver SVX LS-L |
#32
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Then I'll ask again.....what is the trick? I understand that it may not be a good idea. What must be done to keep the fuel continuous and power supplied to the tranny while the car is shifting?
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Kevin Thomas 1997 2.2ltr Subaru Impreza Outback Sport Wagon (AWD/Auto) 13.03@100mph 1989 2.7ltr Subaru XT6 (AWD/Auto) 15.912@85.93mph 1996 3.3ltr SVX (AWD/Auto) 15.070@91.38mph ***R.I.P*** 2010 RAV4 AWD Sport (13.717 @ 99.19mph ) 2015 Honda Fit LX CVT (15.2 @ 90mph) |
#33
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Here ya go Kevin
Well crap...the picture won't show.....look at the properties of the "pic" and paste it's address into the adress bar...
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Huck Subaru Ambassador 92 SVX LS-Tour Magnaflow Exhaust, 5-Spd-AWD 88 XT6 AWD 5-Speed "Bride of FrankenWedge" 15 Impreza Premium Sedan 15 Crosstrek XV 5-Speed My 5-Speed "How-To" Write-up 1976 Pontiac Firebird Formula Current Count of Subaru's Owned.... "70" |
#34
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Find pin #a4, It wont have a wire in it (if you look real hard you can see the #s on the back of the plug. 3. Take a long piece of stiff 18 to 20guage wire or similar, and strip about 1/4" off the end of the wire. 4. Now bend the exposed copper over so that it will fit in the empty hole in the connector, and also make contact with the pin on the ECU, when you plug it back in. You could use a small amount of super glue to hold the wire in. 5. Plug the connector back into the ECU. 6. Now run your new wire to a on/off switch of your liking. 7. Now run another wire from the second pole of your new switch, to ground. 8. Fire up the car, put in drive, and look at that pretty power light One more way to firm shifts up further would be to use a higher value resister in place of the one behind the battery. I think budfreek was selling premade ones? Now for the torqe controll issue in the ecu, I will direct you to this form. http://www.subaru-svx.net/forum/show...control+bypass Good luck, and let me know how it went.
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IT'S 5:00 SOMEWHERE!!! 92 Liquid Silver SVX LS-L |
#35
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I know that while it was a 4.11 it was not hooked up.
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www.svxfiles.com The first SuperCharged SVX, the first 4.44 gears, the first equal length headers, the first phenolic spacers, the first Class Glass fiberglass hood, the first with 4, 4.44s in his driveway Fiberglass Hood thread My locker 4.44 Swap link |
#36
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Hmmmm.... I'm curious to try switching the torque control wire from the TCU. If it caused the crazy shifting, I guess that would tell me that the TCU is the problem. I'm thinking about monitoring that wire as well, If it is pulling on the tranny under WOT shifts, maybe that would tell me I need a new TCU. I'm gonna check out that website now. Does anyone on the forum happen to have a SVX TCU that they are willing to sell????
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-Steven 1992 SVX Purple and Black 5 speed swap SOLD *1993 SVX Silver and Black *1994 SVX L Barcelona Red FWD |
#37
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hmmm
the website you referenced Myxalplyx doesn't have a tcu right now. I was thinking about the functions that are involved with the transmission during shifts. I don't understand why the TCU would be grounding the signal for extended periods between shifts. What sensor is telling the TCU that the shift is complete. wouldn't this be the first place to look instead of the TCU? I still think that it's the TCU, but I would like to be more certain. If I could check a sensor or sensor lead for voltage, this would be helpful! Any Ideas????
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-Steven 1992 SVX Purple and Black 5 speed swap SOLD *1993 SVX Silver and Black *1994 SVX L Barcelona Red FWD |
#38
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Yep...$25 Shipped sound OK?
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Huck Subaru Ambassador 92 SVX LS-Tour Magnaflow Exhaust, 5-Spd-AWD 88 XT6 AWD 5-Speed "Bride of FrankenWedge" 15 Impreza Premium Sedan 15 Crosstrek XV 5-Speed My 5-Speed "How-To" Write-up 1976 Pontiac Firebird Formula Current Count of Subaru's Owned.... "70" |
#39
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The ECU knows when to cut power, because the TCU tells it, that it is going to shift. But its not an obtuse communication. The calculations being done to tell the trans when to shift, and the engine when to cut power are based on several factor in both the TCU and ECU. For instance, vehicle speed, engine RPM, engine load, current gear, ect. Does the car feel like the brakes are being applied when the trans shifts? I got to thinking that maby the brake band in the trans is too tight. But something you need to understand about why subaru implemented the torque control is, Imagine having a manual transmission and never letting off the gas when you shift, or dumping the clutch every time you accelerate hard from a stand still. Neither the clutch, or the trans would last long.
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IT'S 5:00 SOMEWHERE!!! 92 Liquid Silver SVX LS-L |
#40
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Here is the pic Huck was posting...
Jim
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1992 Dark Teal LS-L with 4.44 swap. NC Plate "EVIL I" *Dont Fear the GEAR* 1977 Ford Pinto baby blue with 79,000 miles |
#41
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Just a note here....This was when it was believe o affect the ECU in a 5-speed, but was determined later that once the TCU was removed during a 5-speed swap, it was no longer needed....so this is NOT needed in a 5-speed swap.
But this WOULD make it not cut the torque down between shifts on a auto.
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Huck Subaru Ambassador 92 SVX LS-Tour Magnaflow Exhaust, 5-Spd-AWD 88 XT6 AWD 5-Speed "Bride of FrankenWedge" 15 Impreza Premium Sedan 15 Crosstrek XV 5-Speed My 5-Speed "How-To" Write-up 1976 Pontiac Firebird Formula Current Count of Subaru's Owned.... "70" |
#42
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OK... as this is my first subaru and I come from years of RWD V8 and turbo4 american cars, what makes the subaru transaxle so fragile that disabling tq management and speeding up the shifts makes it a bad deal?
In the cars I am used to dealing with there is no tq management and speeding up the shifts actually extends the life of the trans in a performance application. Also, the trans in mine is a 4.44 from a 97 legacy OB... what can I do to beef it up to take the full power quick shifts? I plan on the 5 speed swap next year so this MAY be a moot point... but I wnt the most performance from what I have at the moment... and would like it to last until it is removed by choice... not by necessity. I searched but ran across a lot of seemingly contradictory info. Jim
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1992 Dark Teal LS-L with 4.44 swap. NC Plate "EVIL I" *Dont Fear the GEAR* 1977 Ford Pinto baby blue with 79,000 miles |
#43
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I do NOT now if this applies to the 4EAT or not, but I tore apart an old worn out FWD 3 speed automatic, and I noticed that the valve body had "3N71B" cast into it, which is the model # of the three speed RWD auto used in early Mazda RX-7s, as well as Datsun pickups and some RWD Datsun cars... Since I had a 3N71B lying around that was also fried I yanked the valve body out and to my amazement it was nearly identical. I didn't see if it would bolt up in place of the Subaru one, but it was close enough that I think were a shift kit available for the 3N71B, it would work with the Subaru tranny.
I realize that the 4EAT is electronic and uses shift solenoids instead of springs and valves, but if the guts are similar to something else that performance stuff is available for, I wonder if there's anything that'd swap?
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1992 SVX LS-L #1222 Pearl White 1987 GL Turbo wagon, 5 lug conversion, D/R 5 speed (Rice killer) 1992 Dodge Ram 4x4 diesel (car hauler) 1968 Dodge Polara convertible (Camaro killer) 1990 Toyota Corolla FWD auto (330,000 mile grocery getter) 1986 VW Jetta |
#44
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I have a Level 10 Hydrosystem (Valve body job) and tranny cooler on my Outback Sport. Really firm, quick shifts. Lasted for years with nitrous and turbo. Car is celebrating its 12th year anniversary next month. Car shifts (with upwards to 50% extra whp between shifts) and still feels better than new. I highly recommend both (Next plan of action if I can afford them...on my SVX). I have proof of the 50% extra whp between shifts. Neck snapping, steering wheel twisting good times.
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Kevin Thomas 1997 2.2ltr Subaru Impreza Outback Sport Wagon (AWD/Auto) 13.03@100mph 1989 2.7ltr Subaru XT6 (AWD/Auto) 15.912@85.93mph 1996 3.3ltr SVX (AWD/Auto) 15.070@91.38mph ***R.I.P*** 2010 RAV4 AWD Sport (13.717 @ 99.19mph ) 2015 Honda Fit LX CVT (15.2 @ 90mph) Last edited by Myxalplyx; 10-10-2007 at 06:28 PM. |
#45
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Within this thread it has been suggested that torque control could be achieved by either fuel shut off, or via blocking ignition.
I have always understood that some, but not all cylinders, are deprived of ignition for the short periods involved. This would be plausible as control would be practically instantaneous, as opposed to a probable slight inherent delay. Please, can someone confirm the exact mode of operation. Please, no opinions, only exact evidence, e.g. pointers towards verifiable published statements, from an absolutely reliable source exhibiting authority.
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Trevor, New Zealand. As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit! |
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