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
  #16  
Old 10-18-2006, 09:55 PM
TomsSVX's Avatar
TomsSVX TomsSVX is offline
Maniac modifier
 
Join Date: Dec 2003
Location: Branchburg, New Jersey
Posts: 15,489
Registered SVX Classic SVX
If you are going to keep the car RWD, go buy an R180 and a pair of rear axles... It'll cost about $500 but it'll be worth it. Also, you are triggering the ABS with burning out the rear wheels only... THe sensors are reading a lock up in the front and not in the rear so the ABS will fire the fronts and effectively the rears as well

Tom
Reply With Quote
  #17  
Old 10-19-2006, 03:29 AM
UberRoo's Avatar
UberRoo UberRoo is offline
SVX Appeal
 
Join Date: Feb 2004
Location: Puget Sound, Washington
Posts: 843
I have a spare differential, so I'm gonna beat on this one until it explodes. ...if it explodes. I'm curious to see how long it lasts. It'll probably last longer than I can stand living without AWD.

Initially, it makes sense that the ABS is simply confused, but I don't follow why the ABS would be triggering the rear because of a lockup in the front. I believe it's a four-channel system, so applying brake to the rear would have to be a deliberate action by the ABS. I suppose I can see why it might think more brake in the rear would be appropriate, but I don't believe ABS systems ever add more brake. If that were the case, under normal circumstances any one wheel experiencing a traction loss would cause the ABS to apply more brake to the other three wheels, slowing the car down more than the driver demands given the applied brake pressure. By applying more brake, it also risks further upsetting the balance of the car and possibly locking up the other wheels which are its only reference to vehicle speed. The appropriate response of the ABS upon sensing a locked up condition, is to unlock the locked wheel(s). In my case (doing a brake stand), this should cause the car to roll forward, which it does not do. I'm not sure how obvious that is to the ABS computer however.

Then again, the finer points of how ABS systems work isn't my specialty, and it probably varies anyway.

I'm hesitant to declare outright that the SVX has a traction control system because I can still think of other possibilities. Perhaps the transmission senses the very high wheel speed and relatively light load, and decides to shift to second gear (I thought I had the selector in first, but in retrospect I'm not sure I did.) The engine didn't rev higher than 4500 RPM. Further tests will entail holding the throttle open a bit longer to see if it shifts back to first or if the ABS decides it's time to roll again. I'll also have to try chocking the front wheels or tying off to avoid using the brakes. (Too bad these things don't have front parking brakes like the old ones do. Those were the most bestest parking brakes ever.)

Another possibility is that the LSD clutches need a bit of action before they start working. I know some cars have exotic viscous-coupled, torque-sensing fluid systems and such that only bind up after they've been slipping for a moment, but I recall that the SVX just has an ordinary limited-slip differential.

The feel, and especially the noise, is very similar to what I've experienced when climbing snowy hills near the threshold of traction. (That particular symptom disappeared when I hot-wired the transfer clutch to remain locked in a 4WD mode.) It definitely feels like the ABS is doing something, but I'm still puzzled about exactly what it's doing and why.
__________________
1994 LSi, Laguna Blue SVX Appeal
1992 LS-L, Ebony Pearl SVX-Rated
UberLocker
Reply With Quote
  #18  
Old 10-19-2006, 05:25 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 unplug the ABS unit under the hood.....you can always plug it back in when you're done with your burn out....
__________________
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
  #19  
Old 10-19-2006, 06:41 AM
benebob's Avatar
benebob benebob is offline
Have a poncho I can borrow?
 
Join Date: May 2001
Location: Lancaster, PA
Posts: 6,561
Quote:
Originally Posted by andrew.anderson
While your results where not desirable, it is cool that you undertook this project and it worked...kind of.

I have not heard of anyone doign this before...I do not keep up on all the posts here though.

We did it 2 years ago for a race. It was a blast and eventually that's the direction I think we'll take.
__________________
British vehicles are my last ditch attempt to keep the nasty Italian thoughts in my mind at bay. So far its working.
Reply With Quote
  #20  
Old 10-19-2006, 04:33 PM
oab_au oab_au is offline
Registered User
Subaru Gold Contributor
 
Join Date: Mar 2001
Location: Coffs Harb, Australia.
Posts: 5,032
Significant Technical Input Registered SVX
The ABS .

UberRoo, the ABS is causing the short burnout. When the ABS operates, as it does when you hold the brake on while the back wheels are spinning, the TCU puts the box into 3rd gear, regardless of where the lever is.

Harvey.
__________________
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.
Reply With Quote
  #21  
Old 10-19-2006, 05:36 PM
SomethingElse's Avatar
SomethingElse SomethingElse is offline
word words wording
 
Join Date: Jun 2005
Location: CO
Posts: 1,387
Send a message via AIM to SomethingElse Send a message via MSN to SomethingElse
Man ...I cant wait to try this
__________________
Eric

Rebuilt P/S pump info... http://www.subaru-svx.net/forum/showthread.php?t=50918

If your car wont start info... http://www.subaru-svx.net/forum/show...ighlight=click
Reply With Quote
  #22  
Old 10-19-2006, 05:37 PM
UberRoo's Avatar
UberRoo UberRoo is offline
SVX Appeal
 
Join Date: Feb 2004
Location: Puget Sound, Washington
Posts: 843
Quote:
Originally Posted by oab_au
...the TCU puts the box into 3rd gear, regardless of where the lever is.
Ah... The simplest explanation is usually the correct one. That definitely explains why it feels like the engine is losing power.

But then I'm still don't think that accounts for everything; The ABS-like grinding noises, or the fact that first one wheel spins and then the other one spins before they both stop.

I also sensed that something was curtailing my performance even during rolling burnouts. I figured it was the transmission shifting, but I didn't have enough space to let it play out completely.

Obviously I need to do some experimenting.
__________________
1994 LSi, Laguna Blue SVX Appeal
1992 LS-L, Ebony Pearl SVX-Rated
UberLocker
Reply With Quote
  #23  
Old 10-19-2006, 05:43 PM
benebob's Avatar
benebob benebob is offline
Have a poncho I can borrow?
 
Join Date: May 2001
Location: Lancaster, PA
Posts: 6,561
Quote:
Originally Posted by UberRoo
Ah... The simplest explanation is usually the correct one. That definitely explains why it feels like the engine is losing power.

But then I'm still don't think that accounts for everything; The ABS-like grinding noises, or the fact that first one wheel spins and then the other one spins before they both stop.

I also sensed that something was curtailing my performance even during rolling burnouts. I figured it was the transmission shifting, but I didn't have enough space to let it play out completely.

Obviously I need to do some experimenting.
Ours was shall I say very spirited performance wise considering it still had a front dif that was grinding itself to bits with every inch travelled, it was a very tired SVX tranny that had some slippage issues and we were racing on 1/3 Ice/hard snow pack, 1/3 slush and 1/3 dry pavement. It simply booked considering. As for the rear dif, no one wheel spins in our case.
__________________
British vehicles are my last ditch attempt to keep the nasty Italian thoughts in my mind at bay. So far its working.
Reply With Quote
  #24  
Old 10-28-2006, 05:00 PM
SomethingElse's Avatar
SomethingElse SomethingElse is offline
word words wording
 
Join Date: Jun 2005
Location: CO
Posts: 1,387
Send a message via AIM to SomethingElse Send a message via MSN to SomethingElse
Was it neccasary to drill through the friction plates and insert dowels? wont the top and the bottom friction plates wear out faster?
__________________
Eric

Rebuilt P/S pump info... http://www.subaru-svx.net/forum/showthread.php?t=50918

If your car wont start info... http://www.subaru-svx.net/forum/show...ighlight=click
Reply With Quote
  #25  
Old 10-28-2006, 05:18 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
Quote:
Originally Posted by SomethingElse
Was it neccasary to drill through the friction plates and insert dowels? wont the top and the bottom friction plates wear out faster?

No, as inserting the dowels, locked it, so there is no slipping, so the will be no wear on any of the fiction plates in the transfer clutch pack.
__________________
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
  #26  
Old 10-28-2006, 07:45 PM
TomsSVX's Avatar
TomsSVX TomsSVX is offline
Maniac modifier
 
Join Date: Dec 2003
Location: Branchburg, New Jersey
Posts: 15,489
Registered SVX Classic SVX
If you have pictures of the dowels in the friction plates I would like to see them... Thanks

Tom
Reply With Quote
  #27  
Old 10-28-2006, 08:29 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
Quote:
Originally Posted by TomsSVX
If you have pictures of the dowels in the friction plates I would like to see them... Thanks

Tom

He has to have drilled through the metal plates, and friction plates, then put dowels trough them to make them one solid unit, so all the power would be transmitted to the rear driveshaft.

Next step would be to remove all the front diff parts, to lighten it up some, just leave the outer section of the axles to hold the bearings together....

Sounds like fun (I'm an old Firebird owner, and I miss lighting up the rear tires once in a while )
__________________
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
  #28  
Old 10-28-2006, 08:48 PM
TomsSVX's Avatar
TomsSVX TomsSVX is offline
Maniac modifier
 
Join Date: Dec 2003
Location: Branchburg, New Jersey
Posts: 15,489
Registered SVX Classic SVX
The only thing you could remove from the front diff is the ring gear... The carrier needs to hold the axles unless you take the axles out and leave the outer CV's in... You would want to leave the pinion gear in because it seals the diff front the tranny

Tom
Reply With Quote
  #29  
Old 10-29-2006, 01:09 PM
Hocrest's Avatar
Hocrest Hocrest is offline
Freezepop's are Awesome!!!!
Subaru Silver Contributor
 
Join Date: Oct 2003
Location: Pittston, PA
Posts: 5,334
Send a message via AIM to Hocrest
Quote:
Originally Posted by TomsSVX
... unless you take the axles out and leave the outer CV's in...

Wouldn't a set of rear axle stubs from a front wheel drive Soob be easier and lighter??
__________________
Dave
- 03 Baja - 92 SVX - 86 Brat - 08 OB 3.0
Reply With Quote
  #30  
Old 10-29-2006, 02:37 PM
TomsSVX's Avatar
TomsSVX TomsSVX is offline
Maniac modifier
 
Join Date: Dec 2003
Location: Branchburg, New Jersey
Posts: 15,489
Registered SVX Classic SVX
i am not sure the splines are the same...

Tom
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 09:03 AM.


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