spdngdragon

iTrader: (3)

Hi guys,

We've been having some snow in the Seattle area so I have definitely been having some fun with it. My question is: When you are on a slippery surface, and you apply throttle fast, does your back end kick out, and if so to what side? My back end always wants to kick out to the left side when accelerating hard on a slippery surface in a straight line. I just wanted to check if this is what everyone else experiences.

thanks, and have fun out there.

turbotalawd

iTrader: (11)

Same thing happens here. Im guessing its due to the direction the driveshaft spins.

spdngdragon

iTrader: (3)

I was thinking about that...but it didn't seem like any moments were around the z axis of the car.

spdngdragon

iTrader: (3)

Doing a little searching on the web and looks like part of the issue might be torque...the torque being applied to the rear differential pushes one wheel into the ground and lifts the other one up.

The other contributor might be gyroscopic precession. But from what I can gather, this should only happen if I am shifting the axis of rotation...so not sure if when I gun it I am lifting the axis of the engine/tranny combo enough to create a measurable force...
Link to some Info

Some more info

turbotalawd

iTrader: (11)

Right so wouldnt it be from the torque provided to the rear diff by the direction that the drive shaft spins?

Same like on rwd cars w/o a locked diff. Thats why they have those one wheel wonder burnouts.

barneyb

You need a solid axle for torque to push one wheel into the ground. The differential on an Evo is bolted to the body. It is not going to move much and even if it did the axles flex. My guess is that the thrust angle of the rear of the car isn't quite straight. In other words, the toe is off on the back.

spdngdragon

iTrader: (3)

Lol You know I was so busy trying to think of possible forces and how they were getting transferred around that I forgot about the fact that we don't have solid axles in the back. Pretty bad. If the toe is out in the back then something must have slipped. I just had my alignment done a few months ago.

deylag

iTrader: (23)

I have auto-xed in pouring rain on an airfield. The back end does break out but when that happens I countersteer in the direction I want to go and floor it. It straightens out the Evo completely. I have never experienced torque steer as you are describing.