Grand Sport Suspension
07-06-2010, 05:24 PM
#21
Instructor
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St. Jude Donor '11
Can someone answer, with the megnetic shocks on the 2010 (F-55) do you have a switch as in previous years? Will this be the case on the 2011?
07-06-2010, 06:49 PM
#23
Le Mans Master
We also have a Vette with MSRC, and the GS ride is just as good. We were very pleasantly surprised! 
The GS I test-drove a couple of weeks ago gave a much harsher ride on the less-than-smooth roads here in RI. My 05' coupe with the base suspension but modified with Z51 shocks and sway bars gives a much smoother ride. It all depends on where you live. I think the hot setup will be a 2011 GS with the F55 option.
07-06-2010, 07:10 PM
#25
Team Owner
I just finished putting a GS conversion on my '07 Z51 coupe. Per GM replacement parts (thanks Gene and Patrick), I found the following:
GS, Z51 and Z06 all use the same front sway
GS and Z06 use the same rear sway ... Z51 is smaller
GS and Z51 use the same springs ... Z06 is stiffer
GS and Z06 use the same front shocks ... Z51 is different
GS, Z51 and Z06 all have different rear shocks
Base model uses completely different parts.
), I found the following:GS, Z51 and Z06 all use the same front sway
GS and Z06 use the same rear sway ... Z51 is smaller
GS and Z51 use the same springs ... Z06 is stiffer
GS and Z06 use the same front shocks ... Z51 is different
GS, Z51 and Z06 all have different rear shocks
Base model uses completely different parts.
So, if this info is true then I was partly right and partly wrong in my earlier argument.
The Grand Sport suspension is a unique hybrid of old Z51 and Z06. To summarize:
The Grand Sport suspension is:
......Z51 springs and front sway bar
......Z06 rear sway bar (this kind of makes sense)
......Z06 front shocks
......UNIQUE rear shocks
07-06-2010, 07:23 PM
#26
Safety Car
Thank you j4three for sharing this info. This is the first and closest to authoritative I've seen on this but.......I don't know if all of us are ready to completely accept it as fact yet. We'll see.
So, if this info is true then I was partly right and partly wrong in my earlier argument. The Grand Sport suspension is a unique hybrid of old Z51 and Z06.
To summarize:
The Grand Sport suspension is:
......Z51 springs and front sway bar
......Z06 rear sway bar (this kind of makes sense)
......Z06 front shocks
......UNIQUE rear shocks
So, if this info is true then I was partly right and partly wrong in my earlier argument.
The Grand Sport suspension is a unique hybrid of old Z51 and Z06. To summarize:
The Grand Sport suspension is:
......Z51 springs and front sway bar
......Z06 rear sway bar (this kind of makes sense)
......Z06 front shocks
......UNIQUE rear shocks
Makes sense! GS vs Z51 vs Z06 components
The larger rear sway bar accounts for the larger rear tires for the GS and Z06.
The shock valving is tailored to the model and tire widths, GS, Z51 and Z06.
07-06-2010, 07:35 PM
#27
Racer
Member Since: Sep 2006
Location: Memphis TN
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St. Jude Donor '08
Thank you j4three for sharing this info. This is the first and closest to authoritative I've seen on this but.......I don't know if all of us are ready to completely accept it as fact yet. We'll see.
So, if this info is true then I was partly right and partly wrong in my earlier argument. The Grand Sport suspension is a unique hybrid of old Z51 and Z06.
To summarize:
The Grand Sport suspension is:
......Z51 springs and front sway bar
......Z06 rear sway bar (this kind of makes sense)
......Z06 front shocks
......UNIQUE rear shocks
So, if this info is true then I was partly right and partly wrong in my earlier argument.
The Grand Sport suspension is a unique hybrid of old Z51 and Z06. To summarize:
The Grand Sport suspension is:
......Z51 springs and front sway bar
......Z06 rear sway bar (this kind of makes sense)
......Z06 front shocks
......UNIQUE rear shocks
It's my pleasure to try to contribute after all the info I've gotten from the forum.
I haven't looked at the part #s on an actual Z06 or GS, so I don't know what they are. As most of us know, just because a part is listed as a replacement part does not mean it is actually put on the car at build time. The fuel pump on the '08 (and maybe newer, I don't know) LS3 is an example as the replacement part is a Z06 pump but the pump from the factory is not.
BTW, the chart listing sway sizes and spring rates is an excellent reference that I have used many times.
03-30-2012, 07:52 PM
#28
Melting Slicks
Member Since: Jul 2010
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Anyone know where the dia of the sway bars is measured? I have a '12 GS, my rear sway bar measured in the middle of the bar is 28.3mm so is off the chart in this thread. It looks to me like there have been more updates for the 2012 than has been advertised.
03-30-2012, 08:45 PM
#29
Safety Car
We've been discussing this for a year and so far I haven't seen any spring rate charts that include the GS and now we are trying to confirm which springs the 2011 GS with F55 will have. So the best right now is some deductive reasoning.
All C6's start with the same "standard" suspension, known as RPO FE1...seen here from the Order Guide:
Then up until the 2010 Model Year you either "added" the F55 Mag Ride Shocks, which does not mention or include "different" springs:
OR you opted for the RPO Z51, which does mention and include "different" springs, shocks and sway bars but NOT the F55 shocks:
Starting in 2010 with the GS, which is a "separate" model, the Order Guide shows the same listings for the "Base Coupe and Convertible" as far as the FE1 base suspension and the only option is adding the F55 shocks to the base suspension, same as prior years.
For the GS, the Order Guide only lists ONE suspension, standard on all GS's, RPO Z16:
Notice the exact same words used to describe both the Z51 and Z16 extra cooling, stiffer springs and sway bars and specific shocks? Does that mean the GS HAS the old Z51 suspension? I (most of us) think so but not everyone agrees. Some seem to think the GS suspension is unique, somewhere between the Z51 and Z06 and I haven't seen any documentation to prove either.
Then you throw in the 2011 GS now offering the F55 option, with no mention of "different" springs:
It is known fact that on the Base Coupe and Convertible the F55 shocks are "added" to the base FE1 suspension, no different springs. So one must conclude that the F55 shocks for the GS are "added" to the base GS Z16 suspension. Yes? Yet some here are saying and believing that the GS with F55 is getting "softer" springs and shocks. But again I haven't seen any proof either way.
Bottom line, I deduce that the GS has the old Z51 suspension and the 2011 GS with F55 will have the F55 shocks "added" to the Z51 suspension, the way F55 should have been all along (my editorial).
If I'm proven wrong I'll admit I was wrong, but I don't think I am.
Reference C5 and C6 spring and sway bar chart:
All C6's start with the same "standard" suspension, known as RPO FE1...seen here from the Order Guide:
Then up until the 2010 Model Year you either "added" the F55 Mag Ride Shocks, which does not mention or include "different" springs:
OR you opted for the RPO Z51, which does mention and include "different" springs, shocks and sway bars but NOT the F55 shocks:
Starting in 2010 with the GS, which is a "separate" model, the Order Guide shows the same listings for the "Base Coupe and Convertible" as far as the FE1 base suspension and the only option is adding the F55 shocks to the base suspension, same as prior years.
For the GS, the Order Guide only lists ONE suspension, standard on all GS's, RPO Z16:
Notice the exact same words used to describe both the Z51 and Z16 extra cooling, stiffer springs and sway bars and specific shocks? Does that mean the GS HAS the old Z51 suspension? I (most of us) think so but not everyone agrees. Some seem to think the GS suspension is unique, somewhere between the Z51 and Z06 and I haven't seen any documentation to prove either.
Then you throw in the 2011 GS now offering the F55 option, with no mention of "different" springs:
It is known fact that on the Base Coupe and Convertible the F55 shocks are "added" to the base FE1 suspension, no different springs. So one must conclude that the F55 shocks for the GS are "added" to the base GS Z16 suspension. Yes? Yet some here are saying and believing that the GS with F55 is getting "softer" springs and shocks. But again I haven't seen any proof either way.
Bottom line, I deduce that the GS has the old Z51 suspension and the 2011 GS with F55 will have the F55 shocks "added" to the Z51 suspension, the way F55 should have been all along (my editorial
).If I'm proven wrong I'll admit I was wrong, but I don't think I am.
Reference C5 and C6 spring and sway bar chart:
03-30-2012, 09:13 PM
#30
Drifting
The sway bars are hollow, so it's important to know both the outside diameter and the wall thickness in order to determine torsional stiffness, which is the 4th power of the radius. With a hollow bar, you take the fourth power the external radius and subtract the fourth power of the internal radius. I've only seen one post in the last year that talks about wall thickness, so other than relying on Pfadt's chart, it's going to be hard to know with any kind of certainty what the actual performance of each bar is going to be.
04-01-2012, 01:31 AM
#31
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Going back on the F55 system.
On the 2006 C6 A6 F55, the F55 system came with the BASE sway bars. Many of us upgraded the sways to the Z51's which greatly reduced the body (sideward) roll of the car and reduced the steering wheel play to approximately 1/4", it had something like two inches of play because of the body rolling (some referred to it as "precision steering" after the upgrade). The springs were not changed out because the F55 system was tuned to the BASE springs. Of course, you wanted to use "Sport" mode because of nosedive (oversteer) tendecies in the aggressive quick turns under the "Tour" mode. This simple sway bar (Z51) modification really changed the handling of the car and now it was a much more stable platform. It changed the handling from a "Sunday afternoon cruiser" to an aggressive handling car, a big change, no comparsion to previous setup. Now the car is at least competetive to other Corvettes in handling and at high speeds. 
