Bushpig

This question may sounds stupid, sorry... but in this video, at 0:33 seconds we can notice the front wheel spins first. Is it because the power sends to front axle first?

Someone from a subaru forum says the video explains "the evo is based on an FWD platform and sending the power back to the rear wheels when the computer senses loss of traction at 0.33 seconds" ---is it true? I'm so confused

mdsevo06

iTrader: (41)

51/49, but yes, all wheel, all the time.

BostonGTR

iTrader: (1)

Is that a new type of dyno test from down under?

llDemonll

iTrader: (21)

evo drivetrain also doesn't split power to front/rear. it's a static amount going to each all the time

Bushpig

Thanks for your replys, but could you explain the 'lag' at 0:33 seconds

Dr.Chris

I think I read recently that you can tell it is based on a FWD platform because of the transverse mounted engine. AWD cars based on RWD have engines facing 90 degress of the evo. Some all-wheel drive systems start with a rear-wheel drive platform that is adapted to be AWD. This system requires power to be sent to a differential with an additional driveshaft that directs power to the front wheels. This additional driveshaft reroutes power, changing its direction so it can be sent to the front wheels. This extra routing sacrifices efficiency, and the extra componentry creates a drivetrain layout that is not symmetrical and balanced. Often in such systems, most or all of the power is routed to the rear wheels. When slippage is detected, the front wheels are engaged, and by the time power is rerouted, further slippage has already occurred.
Subaru is one of the few that is designed for symmetrical AWD.

gsrboi80

iTrader: (38)

Sorry for the way off topic but OP love the screen name. Hahaha

Gotta see all the Bushpigs I work with

wizechef

iTrader: (4)

That looks super healthy for the transmission.... Smh

kyoo

iTrader: (29)

so much misinformation.. this topic always pops up from time to time..

it's full time awd, all the time 50:50 distribution.

the traction thing is just the way the center diff locks up the front and rear

barneyb

The last time I was at a Subaru dealership they had literature showing how their "symetrical" AWD was somehow better. Well, this is marketing hype.

luis!

iTrader: (10)

couldn't have said it better myself

gaabbee

Think about it like a clutch. Which it technically is, one shaft has to spin to get the other going before it locks together.

deylag

iTrader: (23)

Yep Kyoo is right. The Evo has full time awd. Wheel slippage is due to a lot of factors that have nothing to do with the AWD system.

Front wheel and Rear Wheel slippage can be obtained with the following issues:

1. High Tire Pressure

2. High Horse power launch

3. Excessive Camber

4. Worn out Caster Bushings.

5. Worn Out Center Diff. (clutch packs need to be replaced)

6. Improper Launch Technique.

7. Worn Out Front Diff.

blowngasket

iTrader: (4)

could depend on WHAT center diff he has, a Quaife ATB will send power to the wheels that have MORE traction, unlike the convention Open Diff with spider gears that works like a regular differential.

barneyb

I know this quote is taken directly from the Quaife web site but it is an incomplete statement. It should read - a Quaife ATB will send power to the wheels that have more traction while also sending power to the wheels that have less traction.

All any limited slip differential does, whatever the design, is apply some clamping force between the output shafts, usually axles, but not axles in the case of the center differential. This clamping force resists the output shafts turning at different speeds. They are to some extent locked together. Depending on the design, the clamping force can be a little or a lot and work slowly or fast. Most designs depend on the torque applied to the differential to apply the clamping force. Thus, when the throttle is closed the clamping force is less or removed.