Torque induced over/understeer PP1

[bomlodr]

This is my first experience with a Torsen LSD. That said, here's what I'm experiencing: long sweeping freeway onramps (left or right, doesn't matter) or fast corners, if I throttle out of corner at the apex, I can feel the car "push" or understeer. I know this as I consciously keep the same steering input. Conversely, if I let off the throttle decelerating, I can feel the car pull back on to a line (not oversteer, though) that is more in the direction of steering input. This happens turning left or right. I assume this is due to how the Torsen functions but as I have no experience, I figured I'd ask someone. Thanks gents.

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[Bluemustang]

This is my first experience with a Torsen LSD. That said, here's what I'm experiencing: long sweeping freeway onramps (left or right, doesn't matter) or fast corners, if I throttle out of corner at the apex, I can feel the car "push" or understeer. I know this as I consciously keep the same steering input. Conversely, if I let off the throttle decelerating, I can feel the car pull back on to a line (not oversteer, though) that is more in the direction of steering input. This happens turning left or right. I assume this is due to how the Torsen functions but as I have no experience, I figured I'd ask someone. Thanks gents.

Do you have any rear suspension mods? Cradle lockout or anything like that? I assume what you're feeling may be just weight shift and also deflection from the rubber bushings in the suspension.

 

[bomlodr]

Bone stock as far as I know. It has roughly 48k miles. If it is deflection, I definitely have some work to do as it seems excessive to me but again, this is my first S550 and my first Torsen so, I don't know what's normal. I'll break out the prybar and check some bushings this weekend.

 

[Bluemustang]

Bone stock as far as I know. It has roughly 48k miles. If it is deflection, I definitely have some work to do as it seems excessive to me but again, this is my first S550 and my first Torsen so, I don't know what's normal. I'll break out the prybar and check some bushings this weekend.

The deflection in the stock IRS (and the IRS cradle in particular) is - frightful. You might have some IRS mods in your future.

 

[Nonsequitur]

This is my first experience with a Torsen LSD. That said, here's what I'm experiencing: long sweeping freeway onramps (left or right, doesn't matter) or fast corners, if I throttle out of corner at the apex, I can feel the car "push" or understeer. I know this as I consciously keep the same steering input. Conversely, if I let off the throttle decelerating, I can feel the car pull back on to a line (not oversteer, though) that is more in the direction of steering input. This happens turning left or right. I assume this is due to how the Torsen functions but as I have no experience, I figured I'd ask someone. Thanks gents.

What you are experiencing is perfectly normal in a stock car. Factory settings are usually on the safe side meaning understeer under power and nose tuck in when lifting off.

Bluemustang is right. Deflection in the stock suspension is horrendous. Using aftermarket parts to take out the slop and stiffen everything up makes a world of difference in this car.

 

[bomlodr]

Thanks, gentlemen. That's the info I needed!

 

[Champracerj]

This is my first experience with a Torsen LSD. That said, here's what I'm experiencing: long sweeping freeway onramps (left or right, doesn't matter) or fast corners, if I throttle out of corner at the apex, I can feel the car "push" or understeer. I know this as I consciously keep the same steering input. Conversely, if I let off the throttle decelerating, I can feel the car pull back on to a line (not oversteer, though) that is more in the direction of steering input. This happens turning left or right. I assume this is due to how the Torsen functions but as I have no experience, I figured I'd ask someone. Thanks gents.

I'm new to the S550 Mustang and have been reading a lot on these forums. Its been super helpful. I've heard this complaint but isn't this basic vehicle dynamics? In a corner at or near the grip limit throttle on transfers weight to the rear, thus front tires loose some grip and start to under-steer. Conversely as the OP describes, reduce throttle, lift, transfers weight to the front and lighten the rear thus more front grip the front tire track the path and the rear lighten slips and starts to rotate or turn in.. This is actually desirable, if its predictable and controllable to adjust the attitude of the car in the corner.
I'll be tracking my 2018 GT PP2 in 2 weeks and hope to see how it all works on the track.

 

[Guarded15]

I'm new to the S550 Mustang and have been reading a lot on these forums. Its been super helpful. I've heard this complaint but isn't this basic vehicle dynamics? In a corner at or near the grip limit throttle on transfers weight to the rear, thus front tires loose some grip and start to under-steer. Conversely as the OP describes, reduce throttle, lift, transfers weight to the front and lighten the rear thus more front grip the front tire track the path and the rear lighten slips and starts to rotate or turn in.. This is actually desirable, if its predictable and controllable to adjust the attitude of the car in the corner.
I'll be tracking my 2018 GT PP2 in 2 weeks and hope to see how it all works on the track.

100% correct, this is basic front engine, RWD vehicle dynamics. A 140hp miata with an open diff will do the exact same thing in this situation. One can also use this effect to settle the car down when needed.

From the factory the car is compliant but it is tight enough to be predictable. Stiffening it up may give extremely novice drivers more confidence but ultimately that is going to come at the cost of reduced grip. The only time a really stiff car makes performance sense is when the track is smooth and the driver is skilled enought to exploit the more instantaneous response.

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