I have a 07 GT with a Turbonetics system, 560 hp at the crank.
on the hwy if I drop her into 3rd and roll on the gas once I get to 6 psi and above the rear of the car feels like it is twisting and walking a bit.

If i drop it into 4th and roll on the gas (just to make sure wheel spin is to a min) once I get back into the higher end of boost, same thing.

it's kinda harry, with all the parts in the rear of this car and limited knowledge of cars I'm not sure what to replace to help with this.
any advice would be greatly apreciated.

 

have you dont any suspension mods at all?

Things to replace would include

Lower and upper control arms
Sway bar
Panhard bar and brace

all of those will handle the power in the rear much better

 

suspension from what I can tell is stock

 

Oh yeah you definitely will get sketchy with that much power on a stock rear suspension.. It's having a hard time placing the power.. Honestly, I would go with SF connectors to keep it moving straight and even

 

Your HP numbers are great, but I would think that if you can spin up the tires at highway speeds, I would ask you what tires you are running. I don't have that much HP and never have, but I would like to know what make/model/size of tire and wheel width you are running here.

Secondly, I don't see sub-frame connectors as a likely improvement here, sorry TRex The S197 has a VERY solid frame and while additional support will certainly not hurt, it is probably not the answer here. Furthermore, suspension mods will help to reduce wheel hop, but just pure spinnning tires is an issue of the tires compound.

Please tell us EXACTLY the tires you are running

Jazzer welcomes a happy horse to MF's

 

Goodyear Eagle F1's supercar tires 285/40/18 on the rear chrome 18" SVT GT500 wheels.
its not like they leave black strips on the road, but if I look in the mirror I can see my tire
tracks look a lil lighter on the road, and like I said if she stays hooked and I dont spin the backend
sways back and forth. its not a good feelling

 

Well.... I would expect that tire to hold pretty darn well, so guess you gots lots of HP/T The swaying you describe would be helped a bit by some of those items mentioned by howarmat. Whenever one makes a significant power leap, as you have, one needs to upgrade supporting mods to firm things up. Your car came with soft squishy rubber busings all over the place to make the ride nice. Since you have seen to it that you now have a nice ride, you would be well served to makes some upgrades.

I am gonna send this thread over to the S197 Handling Performance section, as they are gonna be a bit more help for you

Jazzer

 

Thanks Jazzer, sorry if i posted in the wrong section

 

Interested in seeing what you find out since I have the same issue even though I have already upgraded most of my rear suspension.

 

has what you have changed made a difference?

I am looking at the Steeda G trac stage 3 kit