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View Poll Results: Select the choice(s) which best matches your situation(s) | |||
1992, Original tranny never failed, Car never modified | 10 | 11.49% | |
1992, Original tranny never failed, Car modified for higher HP | 2 | 2.30% | |
1992, Original tranny failed, Car never modified | 39 | 44.83% | |
1992, Original tranny failed, Car modified for high HP | 7 | 8.05% | |
1993, Original tranny never failed, Car never modified | 4 | 4.60% | |
1993, Original tranny never failed, Car modified for higher HP | 0 | 0% | |
1993, Original tranny failed, Car never modified | 4 | 4.60% | |
1993, Original tranny failed, Car modified for high HP | 1 | 1.15% | |
1994, Original tranny never failed, Car never modified | 8 | 9.20% | |
1994, Original tranny never failed, Car modified for higher HP | 0 | 0% | |
1994, Original tranny failed, Car never modified | 7 | 8.05% | |
1994, Original tranny failed, Car modified for high HP | 0 | 0% | |
1995, Original tranny never failed, Car never modified | 3 | 3.45% | |
1995, Original tranny never failed, Car modified for higher HP | 1 | 1.15% | |
1995, Original tranny failed, Car never modified | 2 | 2.30% | |
1995, Original tranny failed, Car modified for high HP | 0 | 0% | |
1996, Original tranny never failed, Car never modified | 6 | 6.90% | |
1996, Original tranny never failed, Car modified for higher HP | 0 | 0% | |
1996, Original tranny failed, Car never modified | 5 | 5.75% | |
1996, Original tranny failed, Car modified for high HP | 1 | 1.15% | |
1997, Original tranny never failed, Car never modified | 8 | 9.20% | |
1997, Original tranny never failed, Car modified for higher HP | 1 | 1.15% | |
1997, Original tranny failed, Car never modified | 2 | 2.30% | |
1997, Original tranny failed, Car modified for high HP | 0 | 0% | |
Multiple Choice Poll. Voters: 87. You may not vote on this poll |
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#31
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Re: The failed transmission poll
A simpler poll would be to ask if your SVX is still driving on the road with the original transmission.
I added 2 check points for my old and my project cars.
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David B. SVXipedia @ SVX-IW.COM -- SVX Information Warehouse 2.0 coming...eventually! Ebony 1992 SVX LS-L 5 spd Koni/GC Stebro 187k miles RIP (Rust In Pieces) 1993 SVX 5 spd Koni/GC Stebro Polyurethane bushings still available! |
#32
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Re: The failed transmission poll
Yes, it would be simpler poll but I wanted to see the trends with model year and modification and/or driving style. Actually, if anything, it would be better to re-do the poll with tranny control modification options to see if there are any trends or correlations with them. Maybe engine modifications are less important than how the tranny is controlled!
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Tony 1996 Polo Green Subaru SVX LSi, 168,XXX miles, Redline D4 ATF, Redline 75W90 gear oil, K&N HP-4001 Oil Filter, Mobil 1 5W50 FS (3qt) and 5W30 High Mileage (4qt) Oil Blend, Motul RBF600 Brake Fluid, AC Delco A975C Air Filter, NGK BKR6EIX-11 plugs, Centric Rotors, Power Stop Evolution Carbon Fiber Ceramic Brake Pads 2005 Gray Acura RL, 165,XXX miles, Redline D4 ATF with Lubegard Platinum Protectant, Mobil 1 5W20 High Mileage Extended Performance Oil 2009 Red Toyota Venza, 123,XXX, Mobil 1 5W30 High Mileage Oil 1992 Red Ferrari 348 ts, 82,XXX, Redline everything |
#33
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Re: The failed transmission poll
This thread/poll is still pretty much useless....
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#34
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Re: The failed transmission poll
[QUOTE=Huskymaniac;683800]
Quote:
Question, how long does it take, for your brakes to work when you press the pedal, to increase the pressure in the system? Quote:
Why did they do all this TCU modifications to the box in the first place? If we look at the legacy RS Turbo, that does not use these TCU modifications, on the 1st to 2nd change we can see why they did the mods to the SVX and what effects, the mods have. When the 1st 2nd change is to take place, the shift solenoid shuts its drain to send pressure to the band servo, to lock the front Sun gear, changing the overall gear ratio from 9.74:1 to 5.40:1, if the engine was revving at 5000 rpm in first, it has to slow down to about 3000 rpm for 2nd, This will happen as soon as the band applies to brake the engine speed down to the speed of the box’s new ratio. This causes a ‘bump’ that is felt as the braking happens. To soften this ‘engagement bump’ the line to the band servo, has an Accumulator ‘T’ into it, so that the pressure rise is slowed to allow the band to slip, softening the engagement. The High clutch also has an Accumulator to allow it to slip on engagement. To prevent excessive slipping the Accumulators have their piston spring backed-up by a line pressure that is varied by the throttle pressure, so that the band/clutch engagement pressure ‘bump’ is varied to suit the engines torque. Every auto box has used this system for over 30 years, so why did they change the system. In short they did not think the ‘bump’ was fitting for such an expensive car. To lessen the engagement bump even more, they reduce the line pressure during the change to allow the band/clutch, to slowly slip into engagement. Also because the line pressure is reduced, the accumulator backing pressure is also reduced, to delay the pressure rise and increase the softening, slipping time. This results in a change that is very hard to feel, but at the expense of the early demise of the band/clutch facings, and the generation of more heat. To get some sanity into the mod, they turn off every second fuel injection, to reduce the engine torque by 50% so that the linings will survive longer, and this produces its own problems. The Torque Converter plays an important part in the change. Going back to the Legacy RS, Turbo box, when the 1st /2nd change, changes the gear ratio, the engine driven Impeller is spinning at 5000 rpm, the Turbine connected to the gearbox, is braked to about 3000 rpm. Because we have a speed difference of 2000 rpm, the engine’s torque drives the converter down to a reduction speed of 1.9:0, and a torque multiplication of 1.9:1. So the ratio change is not a direct 1st of 2.785, to 2nd of 1.545 as the converter will match the 1st ratio, and go through every ratio up to the 2nd ratio, to give a smooth reduction of the engine speed. As the engine braking is geared down over a longer time, the loading on the band/clutch engagement is reduced. As the SVX TCU reduces the engine torque before the change, the lack of torque means that the converter is not driven down to match the new ratio, spinning on till the band/clutch engagement slows it, increasing the slipping that the elements suffer, and wasting the energy that would have been transferred during the change. So you don’t need to look too far to see why, this box has such a high failure rate, when controlled by the SVX TCU. Harvey.
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One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
#35
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Re: The failed transmission poll
Interesting post Harvey! I will have to read it a few times to absorb it all. But one things was funny. I read the first part and thought, "won't that cause the parts to fail prematurely". And then you later posted that they traded off feel for premature failure. I know luxury sells and most people aren't car/tech geeks like us but I personally read stuff like this and wonder what the hell were they thinking!
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Tony 1996 Polo Green Subaru SVX LSi, 168,XXX miles, Redline D4 ATF, Redline 75W90 gear oil, K&N HP-4001 Oil Filter, Mobil 1 5W50 FS (3qt) and 5W30 High Mileage (4qt) Oil Blend, Motul RBF600 Brake Fluid, AC Delco A975C Air Filter, NGK BKR6EIX-11 plugs, Centric Rotors, Power Stop Evolution Carbon Fiber Ceramic Brake Pads 2005 Gray Acura RL, 165,XXX miles, Redline D4 ATF with Lubegard Platinum Protectant, Mobil 1 5W20 High Mileage Extended Performance Oil 2009 Red Toyota Venza, 123,XXX, Mobil 1 5W30 High Mileage Oil 1992 Red Ferrari 348 ts, 82,XXX, Redline everything |
#36
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Re: The failed transmission poll
With no miles on the graft it is also kind of redundant. So you have a 92 with 250,000 and the original tranny failed . I have a 96 with 45,000 never failed .No point proven. Adding "At what mileage did your trany fail YEAR AND MILES "? Would prove something to me !
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