The Subaru SVX World Network   SVX Network Forums
Live Chat!
SVX or Subaru Links
Old Lockers
Photo Post
How-To Documents
Message Archive
SVX Shop Search
IRC users:

Go Back   The Subaru SVX World Network > SVX Main Forums > MOD Mania > Transmission and Drivetrain

Reply
 
Thread Tools Display Modes
  #31  
Old 10-08-2007, 07:05 PM
UPnorth362's Avatar
UPnorth362 UPnorth362 is offline
Registered User
 
Join Date: Apr 2007
Location: Miami Beach, FL
Posts: 185
Send a message via Yahoo to UPnorth362
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
__________________
IT'S 5:00 SOMEWHERE!!!

92 Liquid Silver SVX LS-L
Reply With Quote
  #32  
Old 10-08-2007, 08:36 PM
Myxalplyx's Avatar
Myxalplyx Myxalplyx is offline
XT6 is SVX's Daddy
 
Join Date: Apr 2002
Location: New Castle, DE
Posts: 1,113
Send a message via ICQ to Myxalplyx Send a message via AIM to Myxalplyx Send a message via Yahoo to Myxalplyx
Quote:
Originally Posted by UPnorth362 View Post
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

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?
__________________
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)
Reply With Quote
  #33  
Old 10-08-2007, 09:05 PM
huck369's Avatar
huck369 huck369 is offline
Inventor of the 5-speed swap
 
Join Date: May 2001
Location: Somerset, KY
Posts: 5,604
Significant Technical Input Registered SVX
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...
__________________
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"
Reply With Quote
  #34  
Old 10-08-2007, 09:29 PM
UPnorth362's Avatar
UPnorth362 UPnorth362 is offline
Registered User
 
Join Date: Apr 2007
Location: Miami Beach, FL
Posts: 185
Send a message via Yahoo to UPnorth362
Quote:
Originally Posted by Myxalplyx View Post
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?
1. On the ECU find the black 20 pin connector (its the plug on the bottom).
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.
__________________
IT'S 5:00 SOMEWHERE!!!

92 Liquid Silver SVX LS-L
Reply With Quote
  #35  
Old 10-09-2007, 12:56 AM
svxfiles's Avatar
svxfiles svxfiles is offline
There's a storm coming.
 
Join Date: Dec 2001
Location: Wiley Ford WV
Posts: 8,650
Significant Technical Input Registered SVX
Quote:
Originally Posted by UPnorth362 View Post

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 believe that Kevin's car has had the resistor disconnected for quite some time now.
I know that while it was a 4.11 it was not hooked up.
__________________
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
Reply With Quote
  #36  
Old 10-09-2007, 08:42 AM
sd2649's Avatar
sd2649 sd2649 is offline
Driving in Style
 
Join Date: Sep 2007
Location: Corpus Christi, Texas
Posts: 239
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????
__________________
-Steven

1992 SVX Purple and Black 5 speed swap

SOLD
*1993 SVX Silver and Black
*1994 SVX L Barcelona Red FWD
Reply With Quote
  #37  
Old 10-09-2007, 08:53 AM
sd2649's Avatar
sd2649 sd2649 is offline
Driving in Style
 
Join Date: Sep 2007
Location: Corpus Christi, Texas
Posts: 239
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????
__________________
-Steven

1992 SVX Purple and Black 5 speed swap

SOLD
*1993 SVX Silver and Black
*1994 SVX L Barcelona Red FWD
Reply With Quote
  #38  
Old 10-09-2007, 11:21 AM
huck369's Avatar
huck369 huck369 is offline
Inventor of the 5-speed swap
 
Join Date: May 2001
Location: Somerset, KY
Posts: 5,604
Significant Technical Input Registered SVX
Quote:
Originally Posted by sd2649 View Post
Does anyone on the forum happen to have a SVX TCU that they are willing to sell????

Yep...$25 Shipped sound OK?
__________________
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"
Reply With Quote
  #39  
Old 10-09-2007, 02:31 PM
UPnorth362's Avatar
UPnorth362 UPnorth362 is offline
Registered User
 
Join Date: Apr 2007
Location: Miami Beach, FL
Posts: 185
Send a message via Yahoo to UPnorth362
Quote:
Originally Posted by sd2649 View Post
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????
I guess I dont understand your problem? The progams that runs in the ECU and TCU is designed to have this affect on engine power for obvious longevity of the trans.
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.
__________________
IT'S 5:00 SOMEWHERE!!!

92 Liquid Silver SVX LS-L
Reply With Quote
  #40  
Old 10-09-2007, 06:24 PM
Evil One Evil One is offline
Pinto Boosting Freak
 
Join Date: Sep 2003
Location: Holyoke Ma, USA
Posts: 291
Send a message via AIM to Evil One Send a message via MSN to Evil One Send a message via Yahoo to Evil One
Here is the pic Huck was posting...



Jim
__________________
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
Reply With Quote
  #41  
Old 10-10-2007, 05:22 AM
huck369's Avatar
huck369 huck369 is offline
Inventor of the 5-speed swap
 
Join Date: May 2001
Location: Somerset, KY
Posts: 5,604
Significant Technical Input Registered SVX
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.


__________________
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"
Reply With Quote
  #42  
Old 10-10-2007, 10:08 AM
Evil One Evil One is offline
Pinto Boosting Freak
 
Join Date: Sep 2003
Location: Holyoke Ma, USA
Posts: 291
Send a message via AIM to Evil One Send a message via MSN to Evil One Send a message via Yahoo to Evil One
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
__________________
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
Reply With Quote
  #43  
Old 10-10-2007, 10:59 AM
Hondasucks's Avatar
Hondasucks Hondasucks is offline
Subaru Technician
 
Join Date: Aug 2007
Location: Vancouver, WA
Posts: 1,512
Send a message via AIM to Hondasucks Send a message via MSN to Hondasucks Send a message via Yahoo to Hondasucks
Registered SVX
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?
__________________
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
Reply With Quote
  #44  
Old 10-10-2007, 06:26 PM
Myxalplyx's Avatar
Myxalplyx Myxalplyx is offline
XT6 is SVX's Daddy
 
Join Date: Apr 2002
Location: New Castle, DE
Posts: 1,113
Send a message via ICQ to Myxalplyx Send a message via AIM to Myxalplyx Send a message via Yahoo to Myxalplyx
Quote:
Originally Posted by FOMOGO View Post
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?

Jim
Jim,

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.
__________________
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.
Reply With Quote
  #45  
Old 10-10-2007, 09:39 PM
Trevor's Avatar
Trevor Trevor is offline
Registered User
 
Join Date: Feb 2002
Location: Auckland, New Zealand
Posts: 5,223
Registered SVX
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.
__________________
Trevor, New Zealand.

As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit!
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 07:45 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
© 2001-2015 SVX World Network
(208)-906-1122