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  #1  
Old 07-21-2003, 02:44 PM
iyamwutiam
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AWD or NOT?!?!?!?

Thought this may be the best place for this question.

I was reading thru the Japanese/European versus American models of SVX's and I guess I was VERY disappointed to realize/read that our SVXs are actually front wheel drives with rear wheel assists!?!?

Is this true - this would make it a very disappointing car to me - and can you do anything like change differentials or anything to make it a true awd?

Are those Japanese/European transmissions available here ?
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  #2  
Old 07-21-2003, 03:34 PM
Kerven Subaru
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Re: AWD or NOT?!?!?!?

Quote:
Originally posted by iyamwutiam
Thought this may be the best place for this question.

I was reading thru the Japanese/European versus American models of SVX's and I guess I was VERY disappointed to realize/read that our SVXs are actually front wheel drives with rear wheel assists!?!?

Is this true - this would make it a very disappointing car to me - and can you do anything like change differentials or anything to make it a true awd?

Are those Japanese/European transmissions available here ?
The US version of the SVX is All Wheel Drive. The Euro and Japan spec models simply have a different transmission that allows more power to be directed to the rear wheels.

All 4 wheels are still driving the car though.

Mike
Kerven Subaru
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  #3  
Old 07-21-2003, 06:12 PM
gl1674 gl1674 is offline
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Almost all automatic subarus are "front wheel drive with rear wheel assist" - they use transfer clutch that is theoretically inferior to a differential. The only exception I know is the outback VDC.

Your choices are
a) convert to 5 speed manual - it does utilize a limited slip center diff
b) to get a tranny from outback VDC (the latter will require matching harness, TCU and and a fair bit of electrical hacking to make it interoperate with SVXes ECU).

Torsen diff seem to be the best choice for the center diff but that's in VW area of expertise...
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  #4  
Old 07-22-2003, 05:50 AM
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Re: AWD or NOT?!?!?!?

Quote:
Originally posted by iyamwutiam
Thought this may be the best place for this question.

I was reading thru the Japanese/European versus American models of SVX's and I guess I was VERY disappointed to realize/read that our SVXs are actually front wheel drives with rear wheel assists!?!?

Is this true - this would make it a very disappointing car to me - and can you do anything like change differentials or anything to make it a true awd?

Are those Japanese/European transmissions available here ?
YES you are correct.
All the SVX american models with AutoTRans are always FWD with a rear wheel assist. The degree of rear wheel assist depends on if there is front wheel slip and or the throttle opening (TPS) and or engine load and a few other things.

When the gas peddle is pushed to the floor the SVX is 50/50 AWD with full transfer clutch pressure but the transfer clutches will still slip when turning a corner. They have to.

I was thinking as you.... How do I get a non USA trans? But then how would I get parts? Who would fix it? So I don't think about it any more.

Now consider this. Auto or manual, there is no front to rear diff. Are you aware that when a car turns a corner the rear wheels are on smaller turning radius than the front wheels? This is just basic geometry. The rear axle must turn at a slower speed than the front axle when a Subaru turns a corner. There is no f/r diff in a Subaru. Because there is no f/r diff, the transfer clutch pack must slip to compensate for the difference in the f/r axle speeds.

Now this might seem like a not so good thing but you actually end up with all four wheels turning the same speed if you stomp on the accelerator pedal. This tends to push the rear of the car faster into an over steer while turning.

Now look at the other case where the there is a f/r diff such as on USA 4x4's. It this case the front or rear axles can spin becasue the f/r diff will allow it. Ask a few owners about snow traction on hills from a standing start.

Also consider for the SVX that most of the weight is on the front wheels so they will not slip as quickly as the rear wheels. It is really a good system but Subaru has "simplified" the explaination.

The other non USA trans is very complicated. There is a whole other planetary gear set. Much more expensive.

You may also like to know, that one of the SVX owners removed the front axles and welded the transfer clutch shaft and drum together to make a ...a...a... rear wheel drive SVX IDNR who it is but the locker has a picture of the rear wheels smokin in a burn out. Not much weight on the rear end and kiss snow traction good-by.

You could also install a switch with a resistor for solenoid "C" to put the trans in 50/50 AWD but the transfer clutches may go by-by, depending on how often you turn corners.

If you have questions about your SVX handling consider that your RWD may not be working properly.
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  #5  
Old 07-22-2003, 05:59 AM
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Re: Re: AWD or NOT?!?!?!?

Quote:
Originally posted by Kerven Subaru


The US version of the SVX is All Wheel Drive. The Euro and Japan spec models simply have a different transmission that allows more power to be directed to the rear wheels.

All 4 wheels are still driving the car though.

Mike
Kerven Subaru
Yeah and most of the time the USA auto trans has 90% of the engine power to front wheels and 10% of the engine power to rear wheels. Not at all like the Euro and Japan models that have the transfer clutch packs.
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  #6  
Old 07-22-2003, 07:25 AM
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Thanks Commuter, that was a great explanation.

But Mike from Kerven is also right, you would have to consider the system is true all wheel drive, even if the split ratios are different.

Mine is the Japanese one, and more of the drive is fed to the rear all the time, except when slippage is detected. The major difference it makes is in making the JDM and Euro models tend to oversteer under power, and the US models understeer.

I was surprised recently to see my back tyres wearing most, I would have expected the fronts with all the weight and braking they are exposed to.

I would say the same, enjoy the car as it is, it does the business. It might actually be useful to put a switch on the C solenoid, it should make the car more tractable in snow. I suspect your US models might tend to spin the fronts in deepish snow at low revs with 90% of the torque going forwards. Do you agree?

Maybe that's why Subaru had the wisdom to include the MANUAL mode for traction.

Joe
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  #7  
Old 07-22-2003, 11:58 AM
iyamwutiam
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OK - so let see if I got this right - it is AWD - but mainly FWD.
Now someone said making it a manual will make it a 'truer' AWD.
Commuter feels the system is fine the way it is right ?

So is there any benefit to changing to a manual - ther than manuals are infinitely more fun than an automatic?
Can someone point me (link me) to an appropriate thread where this has been discussed.

Also since this is a FWD - basically - are there any sports cars that are FWD ??
I doubt it
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  #8  
Old 07-22-2003, 01:36 PM
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Hi Joe,
Yes Kerven is right it is AWD all the time. It does transfer power from the wheeels that slip to the ones that grip, sort of. If the fronts slip it cannot deliver 100% power to the rear wheels but if the rears slip it can deliver 100% to the front wheels. It is just misleading. Ah... I guess you picked up on my some what leading post. After I learned of the non-USA trans I was some what disillusioned. Do you folks really need that trans? Let me have yours.

iyamwutiam, I drive on 80 everyday right past 23.

I am not that familar with all the car models. I do not know how many are RWD. RWD works better at higher power levels when trying to steer. That's why all the trooper cars are rear wheel drive.

Now on the other hand, if I was going to only road race the SVX and never have it on the street again, I would lock the transfer clutch plates for full time 50/50 power split. That would be a great sports car. However the same thing happens by stomping on the SVX throttle.

Someone told me that when racing a Subaru, if the car over steers, stomp on the gas. If the car under steers, stomp on the gas. It will just correct the problem and straighten its self out. This would be on a race track not on streets with other cars.

The SVX with the auto trans is a highway cruiser and not really a sports car. It's the best car I have owned, not the cheapest but the most all round fun and best compromise in an auto.
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  #9  
Old 07-22-2003, 01:44 PM
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Quote:
Originally posted by iyamwutiam
.............So is there any benefit to changing to a manual - ther than manuals are infinitely more fun than an automatic?.............
Auto is great for highway cruising, stop n go traffic. The manual is not. A 6spd would help but not with stop n go.

Manual is great for acceleration and cornering power slides

Gas mileage? No one knows yet. Not enough data on the 5spds.

Cost? 5sp conversion a little less than rebuilt SOA auto $2800

Reliability? Not enough 5 spds yet to tell. Some clutch and 5 gear problems.
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  #10  
Old 07-22-2003, 02:53 PM
iyamwutiam
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SVX Commuter

I live right off 23 ( Jackson Avenue Exit):
I go to work 23 to 80 to GSP N to Paramus - we have to hook up.
Did you get my PMs with my numbers? I really would like have a chat and have you look over my car.

Right now _ I have a over heating issue. I recently changed the oil pump, water pump , thermostat and had a coolant flush and a tranny flsh. In other words - HELP!!!
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  #11  
Old 07-22-2003, 04:26 PM
UT_SVX UT_SVX is offline
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Re: Re: AWD or NOT?!?!?!?

[QUOTE]Originally posted by svx_commuter
[B]

You may also like to know, that one of the SVX owners removed the front axles and welded the transfer clutch shaft and drum together to make a ...a...a... rear wheel drive SVX IDNR who it is but the locker has a picture of the rear wheels smokin in a burn out. Not much weight on the rear end and kiss snow traction good-by.



I was wondering what had happened to the RWD's.....I moved to Vegas and didn't have internet access when this was becoming a regular Mod discussion. So was there only one and what were results?????(good bad????)
Darren out
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  #12  
Old 07-22-2003, 04:40 PM
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Gas mileage? No one knows yet. Not enough data on the 5spds

Well if you look at it this way. The ration on the auto Transmission VS the 5 speed
Gear auto 5 speed
1st 2.79 3.54
2nd 1.55 2.11
3rd 1.00 1.44
4th 0.64 1.08
5th none 0.78
for Example if you are crusing at 60MPH your RPM is 2050 if you have auto and about 2400 if you have a 5 speed then youare burnning more gas with th 5spd

Again am not that expert but thats my theory
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  #13  
Old 07-23-2003, 04:18 AM
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Quote:
Originally posted by svx_commuter
Hi Joe,
Yes Kerven is right it is AWD all the time. It does transfer power from the wheeels that slip to the ones that grip, sort of. If the fronts slip it cannot deliver 100% power to the rear wheels but if the rears slip it can deliver 100% to the front wheels. It is just misleading. Ah... I guess you picked up on my some what leading post. After I learned of the non-USA trans I was some what disillusioned. Do you folks really need that trans? Let me have yours.

OK, You can have mine right this minute!!

You pay your shipping, I'll pay mine. I have just lost 2nd and Overdrive, brake band gone again.

Very unsatisfactory box. The technician tells me the newer Subie autos have done away with the brake band thingie, it's all clutches now in the newer transmissions.

People keep jumping in to defend Subaru every time I castigate the engineering, but I am convinced they made a serious miscalculation with the matching of this tranny to the car. A number of things are fundamentally "wrong" in my opinion:

i)Too much heat generated, and insufficient OE cooling to deal with the spikes, so shortened ATF lifecycle.

ii)Mismatch between the weight of the vehicle, and the power/torque generated by the engine. Tranny is a very thin slice of meat in this sandwich.

iii)Engine is not powerful enough to break traction at the wheels, which would relieve some of the heat/stress.

iv)They did not take account of, or miscalculated, the driver profile. Gearbox is not tough enough to tolerate traffic lights grands prix, particularly the damn brake band, which I hearby rename The Break Band

Other than those misgivings, and the under-engineered rear wheel bearings, it is undoubtedly the best car I have ever owned.

Joe
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  #14  
Old 07-23-2003, 04:35 AM
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Joe,

I have been thinking that the auto with a lower ratio f/r diff would be nice. As Huck says, it would help the trans out.
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  #15  
Old 07-23-2003, 05:44 AM
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Quote:
Originally posted by svx_commuter
Joe,

I have been thinking that the auto with a lower ratio f/r diff would be nice. As Huck says, it would help the trans out.
Might even let it "Break Traction" to help relieve some tension
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