StanNH

...so why haven't they ever even tested the F55 in any C6?

The latest issue, which pits a C6 GS against a Lotus and a Porsche Cayman, has a blurb about the new 2011 GS which now comes with better tires and the F55 suspension as an available option. They apparently couldn't say enough about the new tire/suspension setup as far as adhesion and improved handling.

It just seems odd to me that all they have ever seemed to test, in the past, was the Z51 setup. It's not like the F55 just miraculously appeared for 2011; it's been around for quite a while. Have I missed something here, or have the car mags completely ignored the magnetic suspension option?

Mike Campbell

Actually, they did test the F55 in the ZR1 & way back in the 50th Anniversary 2004.... What's the diff? They hate Corvettes anyway.

AORoads

Could it be that it wasn't available in that configuration at the time of their test? Or maybe that they did test it prior to, and it didn't measure up; so, rather than slam another Corvette, they omitted it?

calmtgguy

As far as F55 on a coupe, it has been tested, it's been tested on the ZR1 too. The Z51 was the best perfromance set up before the GS, that's why you don't see many tests using the F55. As far as the GS goes, you missed something alright, the last regular production 2010, and the first regular production, 2011 Corvette, VIN# 000048, came off the line on 06/11/2010. Now that the factory is making them, maybe the car mags will be able to get one to test.

Wayne O

"...so why haven't they ever even tested the F55 in any C6?"

According to the Delphi engineer I know who helped develop the MagneRide suspension, GM initially did not want the F55 suspension seen as any sort of a 'performance' suspension which could potentially compete with the Z51 option or even the Z06. From testing at Nurburgring and elsewhere, engineer's knew that even using the Z51 sway bars (with the MR suspension) made a noticeable improvement over the 'base' sway bars but from what I understand, GM marketing execs ruled out using the Z51 sway bars. It was only until the ZR1 that GM began to unleash the true performance potential of the MR suspension.

Corvette has always been on the cutting-edge of controlled suspension technology. Over time, more and more high end and performance type cars are going to controlled suspensions either licensing and modifying Delphi technology or creating their own versions. The Ferrari 599 is an excellent example using a modified, 'F55' MR coil-over suspension. The more racing oriented Ferrari 599XX tweaked the suspension even further with an ultra-high performance system developed in collaboration with Delphi. I believe the control system uses a higher processing frequency, refined algorithms and additional sensors on the suspension wishbones.

Here's the 599XX blazing the Nurburgring course in 6:58.16!

http://www.youtube.com/watch?v=POUcGxbzFSw

I think Car & Driver is simply slow to realize the performance capabilities of controlled suspension technology...they're mired in an outdated perception of F55 suspension which was further reinforced by Corvette itself. The F55 can be much more than a 'cushy' ride. Judging from the ZR1 and the 599XX the performance potential of the controlled MR suspension is obvious! The fact that the ZR1 performs as well as it does at a fraction of the cost of the 599XX is even more amazing. IMO controlled suspensions are the future are Car & Driver would be well-served to test the F55 suspension in a non-ZR1 Corvette. Before changing to a coil-over suspension I used the F55 suspension (w/Z06 sway bars) on the track. IMO it performed surprisingly well especially when considering it was designed primarily for street use. With their mention of the F55 equipped Grand Sport, maybe Car & Driver is slowing coming-around.

As an aside...I know there are pros and cons to each but I wish Corvette would switch to a controlled MR coil-over suspension instead of using the transverse leaf springs. Despite certain drawbacks I think a 4-corner independent coil-over suspension is unquestionably preferable for performance. In defense of the transverse leaf spring Darin Dellinger of Delphi commented in an email, "...the current leaf spring is probably hard to improve upon when you factor in cost, packaging, suspension loads management, vehicle structure, overall mass and functionality. While not perfect, the transverse leaf springs work pretty well for a road car." I know Corvette has many considerations and they design and market the vehicle to their customer demographic with street use as the primary focus. IMO GM should shift their focus, if only with a special edition Corvette, for pure performance. A 'track ready' Corvette direct from the factory a la the Viper ACR-X. This track ready C6 should IMO have a controlled, coil-over MR suspension specifically tweaked for track performance. I'll bet that would catch the attention of Car & Driver. It would certainly get my attention...and my order.

(Note: Delphi Suspension Division was acquired by BWI Group)

HOXXOH

Car mags test bone stock cars and the Z51 owes most of it's performance advantage over the F55 to the tires, sways, and gear ratios. Now that the F55 is available with those items in the GS, it has become the better suspension option.

To truly see what the suspension differences are, would require a comparison test between identically equipped GSs with F55 vs. one without F55.

Bill Dearborn

The difference in handling would have to be substantial to make the F55 worth the extra cost.

A main reason to avoid the F55 is the cost of replacement parts. Shock absorbers are wear out items and depending on how the car is driven the mileage to be expected varies. If a shock fails during the 3/36 part of the warranty GM will replace it, however, if it wears out during the 3/36 you will have to pay for the replacement. Normal replacement shocks are cheap but the variable shocks are high priced and can only be purchased from GM. You can replace 4 non-variable shocks for less money than it costs to buy one variable shock. If you put in non variable shocks to reduce costs then you have to fool the RTD system into thinking the shocks are the correct shocks.

Bill

AFVETTE

Well at least GS owners (that have the F55) won't have to replace the sway bars like the base F55 owners do.

That alone will make the GS version a better handler. Ask any F55 guy that has replaced the sway bars and to a man they all say it made dramatic improvement in handling/performance.

Tom

HOXXOH

It's funny how the replacement cost keeps coming up on these F55 threads. So far, only a couple of instances of failure have been reported compared to hundreds or thousands of conventional shocks being replaced.

The expected lifetime for the F55 shocks is well in excess of 100K miles. So if I have a future failure (I'm at 65K now) a used replacement will be my choice. Considering that the MR shocks have no oil being forced through an orifice, they operate at maximum efficiency throughout their life time. Conventional shocks start dying at the time of installation and need all replaced at the same time. The supply/demand will result in a low price too.

okbkvette

And my hope/belief as well. Betting on the long term viability of the F55 because I do like the options it gives.

filmjay

This. And the GS swaybar upgrade (post purchase) will be ZR1 springs and sways, same as "base" F55 owners swap Z51 sways/springs. Regular F55 guys can do the ZR1 swap too, but it's not recommended w/out the the wider/bigger wheels (and widebody) that the GS already has. I imagine it would make a base F55 fairly tail happy without the extra rubber.

LS WON

Hopefully as more cars become available with F-55 suspension like CTS-V the cost of replacement will go down as time goes by. If not there is always the option of returning back to regular shocks to save $$$$.