S550 Rear Rear Shock Dyno Graphs - Base VS Performance Pack

[Ugly John]

So what would this mean to us V6 guys? I wouldn't say my car bounces, but rather when going over larger humps (like at the beginning of a bridge) or large dips, the car seems to float, especially in the back end.

Are the V6 rear shocks the same as the ecoboost or the GT? Could we just grab a set of PP shocks and slap them in?

How hard is it to swap the shocks? Do you have to remove the springs?

I'm still running stock springs, but my next car purchase will be a set of Steeda progressives in large part to get rid of the floatiness. Would PP shocks be good to run by themselves, or should I wait for the springs?

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[leszek]

Are the V6 rear shocks the same as the ecoboost or the GT?

According to the parts catalog there are only 4 different shocks across the entire model range:

• fastback without PP
• fastback with PP
• convertible without PP
• convertible with PP

 

[DickR]

From my experience with a stock spring GT PP the "bounce" is really relatively weak low shaft speed rebound
and probably compression damping which permits the rear to easily move up and down during some shifts
and various other driver actions or road conditions which "want" to compress or raise the rear springs.
When I installed the Koni rear shocks that Sam Strano sells (from another application) the "bounce" essentially
went away even with the shocks at full soft.

Regarding installation of the PP rear shocks it is simple. Jack up car and put it on jack stands.
Remove wheels for access.
Unbolt upper mount from body and unbolt shock from lower control arm.
Unbolt shock shaft from upper mount. Install new shock in reverse order.
No impact on alignment.

Note: Sam Strano's solution is a little more complicated due to the shock not being designed for our cars.
It is a "make do" for serious SCCA Street class autocrossers until Koni releases shocks specific to our cars.

 

[rcb020]

Kelly, are you going to do this same comparison with the Ford Racing shock?

 

[jbailer]

You mean, what causes the owners to think it's bouncing?

I'm going to go out on a limb and say it's simply because many people have not owned a budget built IRS platform that was designed to perform. They don't really bounce. Well, they do....but it is extremely exaggerated online. ;)

That may be the case with the GT PP, I couldn't say as I don't have one. I wish you could test a EB PP and tell me your impression. Putting Steeda progressive springs on mine reduced the bounce but it is still bouncy. To the point driving down the highway, sometimes it is difficult to drink from a bottle of water. I'm not talking about going over bridges either, I'm talking about flat sections of highway with minor/gradual changes in the road. Bumps that I never felt in my 2010 lowered Mustang. I keep watching for information on improving that for EB. Other than Viking, I haven't seen much for shocks and Viking seems to only refer to GTs.

 

[Jmeo]

That may be the case with the GT PP, I couldn't say as I don't have one. I wish you could test a EB PP and tell me your impression. Putting Steeda progressive springs on mine reduced the bounce but it is still bouncy. To the point driving down the highway, sometimes it is difficult to drink from a bottle of water. I'm not talking about going over bridges either, I'm talking about flat sections of highway with minor/gradual changes in the road. Bumps that I never felt in my 2010 lowered Mustang. I keep watching for information on improving that for EB. Other than Viking, I haven't seen much for shocks and Viking seems to only refer to GTs.

I put Viking Warrior shocks on my PP GT with Steeda Progressives and the bouncing was gone. Absolutely amazing difference in ride. I am sure they will work just fine on your Ecoboost.

 

[BMR Tech]

From my experience with a stock spring GT PP the "bounce" is really relatively weak low shaft speed rebound
and probably compression damping which permits the rear to easily move up and down during some shifts
and various other driver actions or road conditions which "want" to compress or raise the rear springs.
When I installed the Koni rear shocks that Sam Strano sells (from another application) the "bounce" essentially
went away even with the shocks at full soft.

Regarding installation of the PP rear shocks it is simple. Jack up car and put it on jack stands.
Remove wheels for access.
Unbolt upper mount from body and unbolt shock from lower control arm.
Unbolt shock shaft from upper mount. Install new shock in reverse order.
No impact on alignment.

Note: Sam Strano's solution is a little more complicated due to the shock not being designed for our cars.
It is a "make do" for serious SCCA Street class autocrossers until Koni releases shocks specific to our cars.

Interesting.

In my opinion, the low speed C and R are pretty decent on the PP shocks we tested, and should be more than capable of damping a 728lb/in spring.

I have tested the PP rear shocks with well over 1000lb/in - and I thought they performed decently, considering.

I guess it is just a little subjective.

The Vikings, both Warriors and Crusaders - definitely improved the ride quality when I tested them with the base, and PP GT on stock springs, though. Of course, it took some street and track time to find the settings which I prefer.

As you can see, the "base" shocks could use some major low speed improvements, yet the people who are complaining of the bounce are typically PP owners. I don't think my base or PP bounce at all, honestly.

Kelly, are you going to do this same comparison with the Ford Racing shock?

More than likely.

That may be the case with the GT PP, I couldn't say as I don't have one. I wish you could test a EB PP and tell me your impression. Putting Steeda progressive springs on mine reduced the bounce but it is still bouncy. To the point driving down the highway, sometimes it is difficult to drink from a bottle of water. I'm not talking about going over bridges either, I'm talking about flat sections of highway with minor/gradual changes in the road. Bumps that I never felt in my 2010 lowered Mustang. I keep watching for information on improving that for EB. Other than Viking, I haven't seen much for shocks and Viking seems to only refer to GTs.

I try to keep the arguing about the spring designs minimal, but I would never use a progressive rear spring on this car without a very good damper. The low speed control would be "okay" - but higher shafts speeds, and compression travel on that progressive spring - watch out.

 

[BmacIL]

Kelly,
Thoughts on the PP rear dampers with the base springs? I currently have the PP springs and dampers in my garage (all of them), but am curious to see what just the rear dampers might perform like.

 

[BMR Tech]

Kelly,
Thoughts on the PP rear dampers with the base springs? I currently have the PP springs and dampers in my garage (all of them), but am curious to see what just the rear dampers might perform like.

I like that combo.

I have driven on it, and IMO it makes an amazing difference.

 

[BmacIL]

I like that combo.

I have driven on it, and IMO it makes an amazing difference.

Excellent...

I already have the PP rear bar on the car, which was a definite incremental improvement in handling. Next spring I plan to put on some more stuff for handling, but I'd sure like to improve the ride quality a tad. I was thinking that just the rear PP dampers would be a good idea, knowing that the stock twin tubes lacked good rebound control. When you get to certain sections of highway, it's easy to feel the rear continue to oscillate. The front seems to be quite well damped, but I can always feel the rear being unsettled on the 2nd bump.

 

[ABQautoxer]

Can you confirm the PP and non-PP shocks are dimensions are the same? I need to know for legality reasons. Specially the front struts.

Thanks for supplying the dyno, very interesting data.

 

[ABQautoxer]

Sorry for the side discussion, but would the Koni shock replacement (when released) be legal for F-Street?

If it's a direct replacement or insert into the original body, yes. The S197s were.

This is why I care if the non-PP struts are identical in dimensions. I'll take a non-PP set, gut them and put race inserts in them from Koni. BMR are the only people I know that have played with both and might be able to confirm this.

 

[BMR Tech]

If it's a direct replacement or insert into the original body, yes. The S197s were.

This is why I care if the non-PP struts are identical in dimensions. I'll take a non-PP set, gut them and put race inserts in them from Koni. BMR are the only people I know that have played with both and might be able to confirm this.

The dimensions are not exactly the same out back.

I have not been able to go as "in-depth" on the fronts thus far, though.

I am going to take an educated guess, and say the fronts are definitely more similar than the rears. :cheers:

 

[ABQautoxer]

Thanks. What matters for SCCA legality in the front is the distance from the perch relative to the strut ear mounting holes and the angles in between. Mainly if they are any taller, if not I'd imagine all other dimensions are the same.

I didn't know about your rear shock solution so I already got something to work via single adjustable Konis back there like Dick did.

 

[ABQautoxer]

Other than the shock replacement, would you advise anything else for F-Street modifications? Here is my initial plan:

- Tires (RE71R, etc)
- Camber Bolt Upgrade (http://www.mustang6g.com/forums/showthread.php?t=22975)
- Strano Rear Sway Bar (http://www.stranoparts.com/partdetails.php?PartID=1289&CategoryID=296&ModelID=40)
- MBRP Exhaust (No benefit except sound)

Just want to make sure I'm not leaving anything obvious on the table.

So we don't derail this thread, come chat in this one:

http://www.mustang6g.com/forums/showthread.php?t=24778

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