Gearhead Jim

On the base C6, yes.
On the GS, it's like the normal GS suspension (similar to old Z51) but with the magnetic shocks. A different animal.

Cavi

what I still want to knw is the spring rates for the f55 setup, mine has the f55 shocks and the FE2 springs, which should be stiffer than the base FE1, as the FE1 is listed as soft ride and the FE2 as Handleing/firm, and FE3 as sport.

Gearhead Jim

Looking forward to his posts!
Thanks.

PittMD1

F55 with a GS just flat out corrners. In sport mode there was no roll or lean that I could detect and the GY Gen 2's bit the road like a raging pitbull.

Love this car!

phileaglesfan

Don't put A/S tires on it as it'll make the handling worst especially in tour mode (I had an 08).

I was about to go with Pfadt sways on my 08 and will probably do the same with my 11 eventually.

The road near Jerome is real nice.

MisterMidlifeCrisis

I should have this done within the next couple of months. A lot of my HPDE hopes aren't going to materialize this year since I'm just too busy.

I've done four basic things to my 2011 F55: Z51 sways, ride height/rake, poly bushings, and tire pressures.

Gearhead Jim started a thread on ride height a few months back, and through that I found that by rough measurement, the ride height on my vehicle was way higher than that reported by anyone else. Through a series of adjustments and testing, I ended up with an early C6 Z51 spec, which has a lot of downward rake. Over the years, apparently GM has specified a more level ride height for the C6, but I seemed to find that putting the nose down, and presumably the center of gravity, reduced body roll up front and gave me more front end grip. This may be why the early Z51's were known to be so tail happy. With with the stock soft front spring, this reduced the understeer inherent in the spring choice and in combination with higher front tire pressures gave me a very slightly understeering balance.

Despite what the thickness of the Z51 bars might indicate, putting them on didn't really alter handling balance that much. There's WAY less roll, practically none up to 70-80%. I first put them on with the rubber bushings, and all I remember really having to do was to reduce front tire pressures a bit and I got back to that slightly understeering handling balance at the traction limit.

The poly bushings added what felt like 10-15% more roll stiffness but not any more road noise or harshness, but since I'm still running those rock-hard OEM GS-2's, I started losing traction on chatter bumps in mid-corner if I hit them with the outside wheels. It just felt like the tires weren't compliant enough, and these GS-2's have always seemed to take forever to regain traction once they start to slip. Dropping tire pressures helped a bit, as has a month or so to let the bushings break in, but i still have this problem. Admitted, this occurs at pretty high cornering speeds and I'm almost sure this problem will go away when I change tires. The poly bushings have changed the handling balance, since they feel like they've stiffened up the front more than the rear. I have slight to moderate understeer at the limit. More tire pressure up front could help, but then the loss of traction on chatter bumps would be worse. Catch 22, but of course in this situation probably the Z51 front spring is the ideal solution.

Last thing I did was to use the Pfadt aggressive street alignment specs, but to go a little more negative camber up front, to compensate for the softer spring. I'm running zero toe and have very even wear (unfortunately, since I want these tires to wear out so I can swap them).

So, the more I've driven with this configuration, the more I am amazed that someone like TMyers can drive so fast with this mismatched spring rate combo. It is not noticeable up to 70-80%, but above that, and especially in my case where I have a significant downward rake, coming off the brakes lifts the nose and upsets the car balance right at corner entry. Also, each time a change has increased roll stiffness, traction has gone up, but also sensitivity to mid-corner throttle and trail braking has gone up too, so you pay more of a price for hitting a corner with the wrong entry speed. And it is harder at my amateur skill level to recover traction once it is exceeded.

Anyhow, it's good to have had a couple of months in between each of these changes so I can see what exactly happens with each of them. Coming from a lot of HPDE experience in the '90's, I've come to realize that a lot of my traction perceptions are based on how much body roll there is, and now with very little body roll all the time, it's been something else to learn.

Cavi

if you could post your ride hieghts I would appreciate it.

MisterMidlifeCrisis

http://forums.corvetteforum.com/c6-c...oupe-vert.html

Nice Ride

Jim, thanks for the info! Thought you also got enhanced brakes with base car and F55 as well. Guess suspension stays same. Looks like the GS with F55 is the way to go.

JFKLS3

I put the Z51 bars on my 08 F55 vert. The steering is much more precise and it takes the
corners much flatter now. Big improvement.....

FortMorganAl

No, that is why everyone recommends changing to Z51 swaybars if you have F55 and want improved handling rather than Z51 option owners being advised to change to F55 parts. Z51 is no longer available. It was a package of options for performance handling including coolers and gears and improved brakes as well as the sway bars and shocks and springs. It was discontinued when the Grand Sport was introduced.

Yes, F55 is pretty much just magnetic shocks on an otherwise base car. It has an intermediate ride quality between base and Z51 at the expense of intermediate handling.

jimmie jam

"state of art" is more like it. Most would equate that with "top of the line". Some of the most expensive supercars use it, you have to be the judge yourself.

FortMorganAl

So that makes a Chevy Volt "top of the line"?


BTW, the expensive supercars that use it like the ZR1 don't use the same inexpensive parts that the base Corvette has to use to keep the price down. Everything on a car is a compromise.

Driver_WT

I had the Z51 sway bars on my 2008 C6 Coupe with F55, and I found that the back end wanted to come around when getting on the gas at corner exit. I have since switched to Johnny O'Connell sway bars from Pfadt and it is a very nice improvement over the Z51 bars - much better balanced and no oversteer when getting on the gas at the apex of the turn.

My recommendation:
Johnny O'Connell sway bars
Lower car all the way on stock lowering bolts
Michelin Pilot Sport PS2 ZP tires
Pfadt performance street alignment

Wade

Wayne O

IMHO the MR suspension is the best 'all-around' suspension offered by Corvette. Before changing to coil-overs for road course performance I used the MR suspension both on the street and the track with a variety of sway bars, tires, and other modifications. Obviously, how you modify the setup of your car depends on how you use it but even in its stock trim the MR suspension is quite capable. Upgrading the sway bars is a logical first step (see below). If you use the car competitively in-time you'll want to get-away from the runflat tires but IMO they're good to learn with. I found the Pfadt control arm bushing kit gave the car a somewhat more responsive feel...a 'lighter' touch if you will.

If you're not already doing so I suggest you enter HPDE courses...start learning to drive on a road course. NASA and SCCA are two other great road course organizations to start with. Even the parking lot autocross events are good experience. Improve your driving skills in a safe environment where, at your own pace, you can explore the true potential of the car. Again, I think it's beneficial to learn using your street tires before going to more of a 'track' tire. I think improving the sway bars is a given with the F55 option....I'd look to do that immediately. Learn what you and your car can do in its stock, street configuraion. There are others mods you can make to improve the handling of your car (for its specific use and purpose) but IMO you'll find your F55 equipped C6 handles quite well even in its stock trim.

With the MR suspension the Z51 sway bars are an improvement over the 'base' sway bars. When the C6 was being developed engineers knew the Z51 sway bars were better with the F55 option but at that time the marketing execs didn't want the MR suspension perceived as any sort of a 'performance' suspension which might compete with their Z51 option (or even with the Z06).

The Z51 sway bars are a modest improvement for a modest price. If you ever plan on changing to wider, Z06 size tires IMO the Z06 sway bars would be the right choice.

surburban99

I have the F55 package on my 08 coupe. The sport mode is tight enough for me.

TMyers

For the last 3 years I have been the champ in every class I have run in our clubs autocross series, Novice, Stock and Prepped. The first 2 years running the car totally stock, last year added poly bushings and Z51 sways. As it stands I run close to the fastest cars out there. I am sure that if I had the means to run A6 tires I would challenge for fast time of the day every outing.

Where IMO the fault of the F55 system shows up in on the track and in high speed braking zones. The front spring is just to soft and the dive can be excessive. At one track we drive front straight speeds approach 150mph. At about the 3qtr mark is a 35mph chicane. With my track pads on I swear I could pick the rear end of the ground.

Like Wayne I am moving up to coil overs this year. The primary reason for doing this is a failure of the front right shock. It seems like a good time to make the move. Of course the improvement in handling will be nice. I might even swap system back and forth as the process, not counting the electronics is not hard.

ScottJ03

I asked Pfadt

Quote:
Originally Posted by ScottJ03
What do you suggest as far as sway bars for Magnetic Ride, GS - 2012 CE.
Thanks,
Scott
Hey Scott. You've got a couple different options for Mag Ride sway bars. Any of our sway bar options will work just as advertised along with the Mag Ride system without making any changes to the Mag Ride it's self.

If you're occasionally tracking the car casually you should look at our Johnny O'Connell sways. They will offer you a nice increase in performance, and their price point makes them great for street cars. The bars themselves are fixed in the front and have 3 positions of adjustment in the rear.

Your other option is our Heavy Duty - Light Rate sway bars. They will offer overall very similar bar rates to the JO bars, but are adjustable in both the front and rear, and are overall a little lighter than the JO bars are. If you're competing with your car and using street tires this is the best option.

The last sway bar option we have are the Heavy Duty - Heavy Rates. These are the stiffest bars that we manufacture, and are perfectly suited for extreme track use with race tires. With the amounts of grip that are generated with race tires you need large amounts of roll resistance as well, and these are just what you need for that application.

Street Cars - Johnny O'Connell bars are a great balance of price and performance.
Street cars / occasional track cars - Light rates work extremely well, are lightweight and adjustable
Race Cars / Occasional street cars - Heavy Rates are the stiffest bars we offer, best used with race tires.

Let me know if you have any questions Scott! No matter what the application we've got the bars for you.

--
Jarrett

thisismyusername

When I had my 05 F55, I put Z51 front/rear sway bars and Z06 springs and it really tightened up the suspension.

TMyers

Jarrett is a gret guy to work with. I was going to upgrade my Z51 sways to the JOC's this year. But with the coil overs going on that won't be happening.