Awd LSD?????

GC8_Kei · 06-11-2004, 04:09 PM

I own a subaru impreza GC8 which im tuning for the mountain and drift. I know the advantages of a LSD on a rear wheel drive car but with a AWD car what is the best type of lsd and should it be installed on the rear or the front or both?

help me out, thanks

Chachi · 06-12-2004, 04:07 PM

You have a few of options.. Cusco has a diff set which includes a 35/65 split and also comes with front diff. There is also a device that freewheels the front wheels so that the car is RWD available in Japan for about 40,000 yen. The last option is to just to make it RWD by removing axles (?) I know someone who did the conversion but dont know if it was removing the axles or if he did something else. Here is some info on it:

RWD RS

mranlet · 06-12-2004, 06:14 PM

Have you driven it on the mountian yet?

Chances are you may not even need one. If you do decide to get one, the Cusco unit is awesome. I would encourage you not to ditch the AWD in favor of RWD, but if you do decide to do that, you'd be looking at upgrading the drishave, half-shafts, and maybe a new differential. You'd also have to fuse the spider gears together which is irreversable, or just buy an entire STi transmission and VCD, through which you can allocate varying amounts of power to the rear wheels. Being able to retain AWD can give you a serious edge for inconsistent mountian conditions!

If you have the money, the STi VCD is DEFINATELY the way to go - keeping a 10/90 split can really help with the stability and will cut down on the amount of counter steer needed (no modified steering linkage nescessary).

I used to run a Legacy Turbo Wagon that had no drivetrain midifications other than modified mounts so that all of the half-shafts ran straight into the spindles for higher efficiency (less wasted power and excess stress by running at angles). This casued the rear differential to be just about through the top of the floor, but I never broke anything even with all the 350+ hp I was pumping through it (I was one lucky bassturd)

I hope this helps, and I'd be happy to give more input on the subject. Also contact "Coiloverkid" via PM or something - he's converting a Turbo Wagon to RWD for drift competition.

-MR

TeamSLIPdrifter · 07-12-2004, 12:31 PM

Without a front lsd your probably gonna run into alot of understeer with a Sube.

mranlet · 07-12-2004, 12:40 PM

Quote:

Originally posted by TeamSLIPdrifter
Without a front lsd your probably gonna run into alot of understeer with a Sube.

Maybe some on-throttle understeer, but that is probably how you'll want it - spinning when mashing the gas isn't good. The importance of a DCCD or VCD is also sort of dependant on your torque split as well. Even if you do run into some crazy understeer, it's nothing that can't be dialed out with suspension.

When I said "drishave" in my previous post, I meant "driveshaft". I don't know how that happened...

-MR

TeamSLIPdrifter · 07-12-2004, 12:49 PM

Yeh but i know a couple of Sube drivers who say they only got 2 problems. 1 is the famous third chamber problem with all Subarus and 2 is that they constantly get understeer. Especially when trying to carry speed through a corner the car always wants to plow after you hit the peak of the apex. They constantly try to lower spring rates, higher them, this, that, etc. and they keep getting understeer. All Subes have this problem and the new STIs in america have it the worst. But dont get me wrong. I love Subarus and i would love to have one. Of course after you do get a front lsd it should get dramatically better with understeer. If your gripping in touge it can be kinda annoying sometimes especially if the pass has long wide turns you might have problems but if its got tight turns and not so long ones im sure youll do great. And for drifting i personally think theyre pretty good. You can use higher entrence speed then many other cars with Subes for drifting.

mranlet · 07-12-2004, 12:56 PM

You're talking to a EC Legacy Turbo Touge veteran

A lot of the Subarus have 90/10 initial split, so it's essentially like driving a FWD car until you (or they) break traction or cause wheel spin.

What is this "third camber" you're talking about? I've never heard that phrase...

How do they raise and lower spring rates? Are you talking about corner weighting? Or maybe dampening force?

-MR

TeamSLIPdrifter · 07-12-2004, 02:43 PM

Raise and lower spring rates as in adjusting your suspension and the rate wich the it absorbs and releases shock. The third chamber problem is in WRXs mostly. The WRX is notorious blowing out its third chamber in the engine. Im not sure exactly why. I think maybe the position or something. Im sure you can find more at the turbo magazine website, they know everything about Subarus.

TeamSLIPdrifter · 07-12-2004, 02:44 PM

Also generally a lower spring rate is better for drifting.

mranlet · 07-12-2004, 02:59 PM

Oh, CHAMBER, I thought you said CAMBER - haha

Yeah, #3 can be a problem because of where it sits in the block in the EJ20T (not so much a problem in the awesome EJ22T), but if the motor is built right then you'll be fine. The problem you hear about most often is the transmission on the WRX - 2nd gear usually doesn't last past 250hp...

There's no way to raise or lower spring rates other than changing springs. I think what you're talking about is dampening force. For drifting any motorsport, you generally want as high a spring rate as possible for the roughness of the track, and as high a dampening force as possible as well. More dampeninng force on one end will make that end handle better (high force on the front for oversteer, high on the rear for understeer).

Usually higher dampening force on the front is desired for AWD drifting.

- Springs support the weight of the car. Stiffer spring=more force to make the car bounce.
- Dampers/shocks/struts absorb imperfections in the road. stiffer dampers hold the tire to the road better, up toa certian point.

-MR

06-11-2004, 04:09 PM	#1
GC8_Kei Newbie Join Date: May 2004 Location: CT/LA/Boston but soon to be residing at Kansai University OSAKA Posts: 28	Awd Lsd????? I own a subaru impreza GC8 which im tuning for the mountain and drift. I know the advantages of a LSD on a rear wheel drive car but with a AWD car what is the best type of lsd and should it be installed on the rear or the front or both? help me out, thanks

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06-12-2004, 04:07 PM	#2
Chachi Registered User Join Date: Jan 2004 Posts: 107	You have a few of options.. Cusco has a diff set which includes a 35/65 split and also comes with front diff. There is also a device that freewheels the front wheels so that the car is RWD available in Japan for about 40,000 yen. The last option is to just to make it RWD by removing axles (?) I know someone who did the conversion but dont know if it was removing the axles or if he did something else. Here is some info on it: RWD RS

06-12-2004, 06:14 PM	#3
mranlet Smokes Dynamite Join Date: Dec 2003 Location: Tampa, CT, all over the place! Posts: 1,090	Have you driven it on the mountian yet? Chances are you may not even need one. If you do decide to get one, the Cusco unit is awesome. I would encourage you not to ditch the AWD in favor of RWD, but if you do decide to do that, you'd be looking at upgrading the drishave, half-shafts, and maybe a new differential. You'd also have to fuse the spider gears together which is irreversable, or just buy an entire STi transmission and VCD, through which you can allocate varying amounts of power to the rear wheels. Being able to retain AWD can give you a serious edge for inconsistent mountian conditions! If you have the money, the STi VCD is DEFINATELY the way to go - keeping a 10/90 split can really help with the stability and will cut down on the amount of counter steer needed (no modified steering linkage nescessary). I used to run a Legacy Turbo Wagon that had no drivetrain midifications other than modified mounts so that all of the half-shafts ran straight into the spindles for higher efficiency (less wasted power and excess stress by running at angles). This casued the rear differential to be just about through the top of the floor, but I never broke anything even with all the 350+ hp I was pumping through it (I was one lucky bassturd) I hope this helps, and I'd be happy to give more input on the subject. Also contact "Coiloverkid" via PM or something - he's converting a Turbo Wagon to RWD for drift competition. -MR

07-12-2004, 12:31 PM	#4
TeamSLIPdrifter Nice rx7, is it 4 or 6cyl Join Date: Jul 2004 Location: Bartlett, Illinois Posts: 154	Without a front lsd your probably gonna run into alot of understeer with a Sube.

07-12-2004, 12:49 PM	#6
TeamSLIPdrifter Nice rx7, is it 4 or 6cyl Join Date: Jul 2004 Location: Bartlett, Illinois Posts: 154	Yeh but i know a couple of Sube drivers who say they only got 2 problems. 1 is the famous third chamber problem with all Subarus and 2 is that they constantly get understeer. Especially when trying to carry speed through a corner the car always wants to plow after you hit the peak of the apex. They constantly try to lower spring rates, higher them, this, that, etc. and they keep getting understeer. All Subes have this problem and the new STIs in america have it the worst. But dont get me wrong. I love Subarus and i would love to have one. Of course after you do get a front lsd it should get dramatically better with understeer. If your gripping in touge it can be kinda annoying sometimes especially if the pass has long wide turns you might have problems but if its got tight turns and not so long ones im sure youll do great. And for drifting i personally think theyre pretty good. You can use higher entrence speed then many other cars with Subes for drifting.

07-12-2004, 12:56 PM	#7
mranlet Smokes Dynamite Join Date: Dec 2003 Location: Tampa, CT, all over the place! Posts: 1,090	You're talking to a EC Legacy Turbo Touge veteran A lot of the Subarus have 90/10 initial split, so it's essentially like driving a FWD car until you (or they) break traction or cause wheel spin. What is this "third camber" you're talking about? I've never heard that phrase... How do they raise and lower spring rates? Are you talking about corner weighting? Or maybe dampening force? -MR

07-12-2004, 02:43 PM	#8
TeamSLIPdrifter Nice rx7, is it 4 or 6cyl Join Date: Jul 2004 Location: Bartlett, Illinois Posts: 154	Raise and lower spring rates as in adjusting your suspension and the rate wich the it absorbs and releases shock. The third chamber problem is in WRXs mostly. The WRX is notorious blowing out its third chamber in the engine. Im not sure exactly why. I think maybe the position or something. Im sure you can find more at the turbo magazine website, they know everything about Subarus.

07-12-2004, 02:44 PM	#9
TeamSLIPdrifter Nice rx7, is it 4 or 6cyl Join Date: Jul 2004 Location: Bartlett, Illinois Posts: 154	Also generally a lower spring rate is better for drifting.

07-12-2004, 02:59 PM	#10
mranlet Smokes Dynamite Join Date: Dec 2003 Location: Tampa, CT, all over the place! Posts: 1,090	Oh, CHAMBER, I thought you said CAMBER - haha Yeah, #3 can be a problem because of where it sits in the block in the EJ20T (not so much a problem in the awesome EJ22T), but if the motor is built right then you'll be fine. The problem you hear about most often is the transmission on the WRX - 2nd gear usually doesn't last past 250hp... There's no way to raise or lower spring rates other than changing springs. I think what you're talking about is dampening force. For drifting any motorsport, you generally want as high a spring rate as possible for the roughness of the track, and as high a dampening force as possible as well. More dampeninng force on one end will make that end handle better (high force on the front for oversteer, high on the rear for understeer). Usually higher dampening force on the front is desired for AWD drifting. - Springs support the weight of the car. Stiffer spring=more force to make the car bounce. - Dampers/shocks/struts absorb imperfections in the road. stiffer dampers hold the tire to the road better, up toa certian point. -MR