Performance Pack suspension bouncy?

I have a question on the 15 performance pack suspension.
In driving mine, I have noticed that while driving on the freeway the car almost seems slightly bouncy. (or should I say, I am bouncing in my seat) This isn’t because of potholes or bumps but more so the connection points in the slabs of the road.
When driving over potholes / bumps, the car is firm but not uncomfortable. It does not seem bouncy at this point.



What causes this bouncy feeling?

You're just so excited and don't realize your doing it yourself?

I have not noticed this with my PP, but the rear springs seem like they could be stiffer.

Hase said:

What causes this bouncy feeling?

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Factory suspension components not being the best they can be due to compromises in performance and ride quality, plus cost. I would upgrade the shocks and struts plus springs once more choices become available. Look at Koni Yellows when they are available.

Mine felt alittle floaty on the highway, that went away when I installed Steeda springs.

Springs will help with this.

Springs will help a ton.

Springs will change the car completely. When pushed the PP springs have a terrible corner entry double bounce/wiggle that will make you pee a little the first time you experience it. Swapped mine over to Steeda sport springs and sway bars at 800mi or so and it makes the car feel in the road not just on it. Plus they drop it just the right amount without sacrificing ride quality. Definitely a must do mod if you are into that sorta thing.

I appreciate the responses!
So if replacing the springs will help - what causes this behavior on the PP? Is it a matter of the rear springs being too soft or hard? I read that the fronts are only slightly (5lbs) different

I want to understand this as I want it to ride nicely. Not sure I want to drop the car as I live in S.E. Michigan and the roads are not exactly known for their quality.

I think the springs have been the best mod $ for $ that I have done. It makes the car ride much smoother and sticks to the road much better.

Hase said:

I appreciate the responses!
So if replacing the springs will help - what causes this behavior on the PP? Is it a matter of the rear springs being too soft or hard? I read that the fronts are only slightly (5lbs) different

I want to understand this as I want it to ride nicely. Not sure I want to drop the car as I live in S.E. Michigan and the roads are not exactly known for their quality.

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Grimace replied above about what causes this behavior.

Are you thinking the front spring are only slightly different by 5lbs vs. rear springs? If that is the case, that is incorrect. The rear PP springs are around 720-730lbs and the front are 165lbs.

The Steeda springs are only about a 1" drop and I don't think that would cause issues for driving over bad roads as you mentioned.

Todd15Fastback said:

Grimace replied above about what causes this behavior.

Are you thinking the front spring are only slightly different by 5lbs vs. rear springs? If that is the case, that is incorrect. The rear PP springs are around 720-730lbs and the front are 165lbs.

The Steeda springs are only about a 1" drop and I don't think that would cause issues for driving over bad roads as you mentioned.

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The front PP springs are only 5lbs heavier than non PP.

TNcoupe said:

The front PP springs are only 5lbs heavier than non PP.

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Yep. You're right. I found that thread where the rates were shared:cheers:

I looked up the spring rates for a gt vs gt pp. I know the front is only 5 lbs heaver and the rear is 60 lbs heaver.

I have driven a regular GT and I did not notice the bounce I am speaking of. I was wondering if there is 1 thing in particular that is causing it (such as the rear springs being 60 lbs heaver) or if it is a combination of things as Grimace suggested.

I do appreciate all of the input. People are mentioning that springs will help. I am simply trying to understand how all the variables play into the equation.

TNcoupe said:

Swapped mine over to Steeda sport springs and sway bars at 800mi or so and it makes the car feel in the road not just on it.

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Does it feel grounded to the ground now ( ͡° ͜ʖ ͡°)

bounce is usually the inability of a shock/strut/damper to control the springs rate. The spring sets the ride height and weight of resistance and the damper controls the spring.

There are other dynamics and intricacies involved, but that is it at it's most basic.