Dif

Installed Z51 sway bars last week and with a lot of posts lately on this setup, I wanted to share my thoughts.
Everyone that has done this, said it was worth doing.
But, I've hesitated doing it for a while now as I didn't want a rougher ride. At least not a lot rougher ride.
I've put a few hundred miles on since installing the bars last week.
Noticed imediately the steering and steering wheel is a lot tighter.
The ride is "slightly" stiffer but still a nice ride in Tour mode.
In Sport mode, there is more difference in ride and handling, but a little hard to tell until hitting rough spots.
Then the difference is real noticable and can be rough if the road is bad.
Regardless of the mode, the car is tighter and "handling is vastly improved"
I liked the original F55 "ride", but the "improved handling and tightness" far out weighs the slightly stiffer ride.
IMO, the stiffer ride is only noticable when going slow over rough roads.
The suspension and body are now more as one and generates slightly more body jitters from the stiffer suspension.
But, ..
around 30 MPH or more on rough roads, the ride is smoother and suspension is able to work better at isolating the road roughness from body movement.
As everyone said who recommended doing this, the car stays flat and tight in the turns and real tight under heavy acceleration
Before installing the Z51 bars, the body would gently rock/sway side to side when accelerating WOT, ... but not anymore
At highway speeds is where I Really like the improvement.
80 on the highway, in either mode, it's extremely stable and rides rough patches a lot better than I thought it would.
Over a few rough highway spots I travel, it is actually better now with the Z51 bars.

I still like the stock F55 setup but here's why I finally installed Z51 bars.
With anything new it's always great and perfect.
But now with 8,500 miles on the stock F55 setup, I am more aware of the softness / sway in handling and hard acceleration.
It needed a little something to help handle the power these cars generate.
That something was adding Z51 bars, ... but here lies my problem
It's hard to tell how fast these cars are traveling being so great, .... and now it's even harder
Some of the back twisties we travel are good for a "leisurely" 40 - 45 mph cruise.
Now with Z51 bars installed, the car handles "leisurely" at 50 - 55 on those same roads without realizing it.

I've joined the Club and echo what others have said:
With Z51 bars on my F55, the new ride and handling characteristics are worth it

mngreg

I installed the Z51 bars on my 2009 F55 coupe and love the difference that they make. GM should have offered this setup right from the factory!

LJD51

DaveC6ZHZ

Dif: Thanks for the post. Some other guys with F55 who have installed the Z51 bars seem to indicate the chassis unsettling over bumps in a curve is reduced compared to base sway bars. Did you find that also? Thanks.

AORoads

Again, Frank, I think this is a good followup on your thread. And a timely one, as I mentioned before.

The one thing I note is that, unlike most others who have put on the swaybars, you're one who identifies (at least to your feel of the car) that it does ride a little harder in some instances. (but it is a tradeoff that you accept for the tighter steering, control, less body roll, etc.)

I think this is one thing that few comment on (but some have) that any changes to the suspension, don't just "flatten" the handling or increase the sharpness of steering effort. They actually can, and will have an effect on ride quality, as well. How subtle or slight that is, is up to the individual.

Good going~!

Cybernetic Medic

Interesting review. I've been reading the forum for many years before I actually got my 07' with F55 this year. F55 was high on my wish list of options and based on reviews I read here, I always thought I would change out the sway bars with the Z51 counter parts. To read some peoples reviews you would think the stock F55 handled like an old Buick. Well after a couple of thousand miles of driving and reviews like yours I'm not so sure any more. The last thing I want is for the car to get 'twitchy' or 'skittish' on rough roads, especially on curves. The whole point of F55 is to keep the tires in contact with the road. I normally drive in sport mode and only switch to tour mode when I come across a patch of rough or undulating road. I can make the nose dive somewhat by jerking the wheel back and forth but thats not representative of normal driving short of avoiding gators on the interstate. At any rate, I'm not sure having a flatter turn-in is worth giving up having the wheels more firmly in contact with the road. I guess I just need more time behind the wheel to make up my mind. With the end of driving season upon us, at least in the Midwest, I think I'll wait until next year before I decide to change them or not.

Thanks for your follow up and review.

BSE1956

Thanks for the write-up.
I have about 8K on my 09 F55 and this very well might be one of my winter mods.
Just one question: Which type of bushings did you use? Rubber or poly?

vettedoogie

Some of the more telling information here (to me) in bold.
Thanks for the writeup. I have the bars but haven't installed them yet on my F55 '05.

ncvette_1FUNRIDE

I have had the Z51 sway bars on my 2010 F55 equipped coupe for about 10-11 months and I can say that I echo 'Dif' has stated. I love this upgrade and would recommend it to anyone with the F55 that would like a 'tighter' feeling car.

I also have the poly bushings and a Thermal Abs tunnel plate which probably enhance the tightness feeling slightly as well.


Very well stated, by the way.

Knob Jockey

Poly bushings have been reported to make the ride a bit harsher than the stock rubber ones I went with. Great for the track I imagine. I also installed the beefier E.E. tunnel plate with thermal abs, couple of benefits there.

I increased the unsprung weight considerably with bigger wheels/tires and brakes at the same time and my SOTP reaction is that along with the reduction in body roll provided by the bars, the negative effect of this extra weight at the wheels is transferred more directly to the driver.

This is good or bad depending on your use of the vehicle. Sometimes it would be nice to ignore this but it is a Corvette after all and being in tune with the car is a big part of the experience.

IMHO with the Z51 bars driving is more 'involving' and inspires a little more confidence in the corners. It may be a bit more skittish over bumps, but it's a controlled skittishness, if that's even a word.

Best bang-for-the-buck mod I've done.

Just my $.02.

Dif

If by "unsettling" you mean the car tends to bounce a bit before settling down ,.. yes the Z51 bars eliminated that.
Understand though, IMO my stock F55 setup did not bounce excessively.
Example:
On a highway going over a bump/hump I would notice a slight bounce after going over bump,....but it didn't keep bouncing
It would bounce once... slightly .. and that's it.
Of course the more bumps etc,.. the more times it would bounce, but still... only one bounce to each bump

You're Welcome

I highlighted the points I'll comment on for you.
I agree with you on the first highlight and chalk it up to varying impressions/opinons on what someone wants or expects from their car.
Especially a Sports Car
I never thought my F55 rode like a Buick.
I did know it rode soft to an extent for a Sports car so I did understand what some people meant by saying that.
Some people want a rock hard,.. hard driving suspension and should have what they want if that's what they like
I just liked a semi-comfy ride with reasonable handling the F55 offered.

Second highlight:
I was in the exact situation making up my mind that you are.
That's what took me so long to do it and see for myself if I'd like it.
I didn't want to change the ride for better handling if it meant skittering on corners and a real rough ride.
But I did read some informing posts and to loosely Quote one:
"The ride is a little stiffer in Tour mode with Z51 bars. Not as stiff as a stock F55 in Sport mode though.
It's a little bit less than 1/2 way between Tour and Sport mode on a stock F55 setup."
And after reading that, figured if it was like that, I could live with it.
I still had my doubts, but now with Z51 bars on mine, That Quote is spot on and find it's better than I thought it would be
Something I think you can relate to, is you drive in Sport mode all the time except when it gets bumpy.
I can relate, but I always drove in Tour mode
So if you can tolerate the Sport mode you'll like the Z51 bars in Tour mode with the better handling etc.
Of course I'm sure you know when the road gets too rough you can't soften things down with a switch
That was my worry before installing Z51 bars.
But then again I figured it I really don't like it, I'll just put the stock bars back in.
But I'm hooked now and can't see going back.

Third highlight:
Again, you mirror my thoughts trying to decide what I might give up in ride for better handling.
I was afraid of the same thing
But with the rest of the F55 stock setup being what it is, only adding Z51 bars does not add enough stiffness to up and down movement to negate the F55's main function/purpose.
They muffle the F55 function somewhat, but do not over ride the F55 main function.
As I say in my review, it's a trade off, but far from the extreme in relation to a stiffer ride.
Probably the closest thing to a perfect blend of comfort and handling together in one setup.

IMO If someone made sways bars that were half way between the stock F55 bars and the Z51 bars that would be the Perfect setp, but again.. that's just my opinion

Bottom line: I'm not here to talk you into doing this.
You seem totally happy with the stock F55 setup and I don't blame you, I like it a lot.
Just that for me as time went by, I wanted a tad more handling.
From what I'd seen/read, adding Z51 bars seemed the way to go without sacificing too much of the ride.

Just trying to convey detailed feedback, hopefully unbiased,.. to help someone decide from the info one way or the other
And as I said, it's just as easy to put the stock bars back in.
Hope this helps which ever way you decide


I used the Rubber ones to keep the noise and any harshness transmitted through the suspension to a minimum.
Poly's are nice for a more positive function and feel, but I only wanted the benefits of the Z51 sways and nothing else that would add to stiffness etc.

Dif

Thanks Bill
I was hoping to convey just that, being some don't want to give up ride quality.
I didn't either, but the amount of ride quality lost is low on a scale of 1-10.
In relation to that, Handling quality and just the over all feel of the car is high on the scale
The roads here are not the greatest so even with a stock F55 in Tour mode it can be rough riding.
It's all relative, but gaining a lot of handling with only a slight increase in stiffness can't be all bad

peter pan

Like offered on the GS now

BSE1956

Controlled skittishness is an oxymoron, but who cares? I think I get what you're saying. When hitting any bumps while cornering "briskly" any car will have a moment where the wheel is not in perfect contact with the road surface. If the Z51 sways improve the cornering then that's a good thing.

EliteGreg

Too bad you can't add f55 shocks to a z51 :-(

Wayne O

I know one of the lead engineer's (then with Delphi...now BWI Group) who developed the MR suspension for Corvette. He told me when they were testing the MR suspension at Nurburgring he had his team put Z51 sway bars on his test car. He said there was a measurable improvement with the Z51 sway bars. At that time, he said marketing execs ruled against mating the Z51 sway bars to the F55 suspension...they didn't want the F55 seen as any sort of a 'performance' suspension that might compete with the Z51 option or the Z06. With the advent of the ZR1 it appears that corporate mindset seems to be changing.

I also found it interesting that many system engineer's argued against having any user input (tour/sport mode) as the system could be configured to do it all. The primary function of sport mode is wheel control. Here's a direct quote: ""...In the "tour" position, the MR controller emphasizes the sky hook algorithm when setting shocks and when set in "sport", it emphasizes wheel control." Again, marketing execs thought giving the driver a degree of system input and control was a good selling point. With the 2008 model year the overall body control strategies were greatly tweaked and streamlined so the vehicle engineer could more effectively change the performance of the vehicle. "Alternate strategies" were likely employed to augment and improve wheel control and vehicle stability. (my friend wouldn't elaborate on what these "alternate strategies" were).

IMO the F55 is the best 'all-around' suspension offered by Corvette. Controlled MR suspension technology is the future...more and more high end and performance cars are going to this technology. I only wish Corvette would offer a controlled, MR coil-over suspension such as the Ferrari 599 uses.

vettedoogie

Who is the "vehicle engineer"? Can one get a "software/firmware" update to these tweaked/streamlined body control strategies?

cthusker

The Z51 sways are great mod for several reasons but one of the best is it's so easy to do. Took me about an hour to change them out... It's not expensive and if you don't like easy to change back! My advice is try it... if you don't like it change it back! That's one reason I didn't hesitate to give it shot....

BTW.. after almost 4 years of the Z51 sways I can say it's been a great mod for me..

Cybernetic Medic

Dif,

Thanks again for all the detailed response. I know you're not pushing the conversion, just relating your enthusiasm with it. After reading yours and all the other responses, I'm again inclined to make the switch. It is after all, not expensive and very easy to reverse if I don't like it but I don't recall anyone having done that.

It sounds like riding in Tour mode with Z51 bars and stock bushings is the sweet spot as far as a trade off between ride and handling.

Dif

Since putting on the Z51 bars, I'm noticing the ride has, softened ever so slightly, with the added miles put on since the change over.
Not drastically softer, more like everything has settled and is more compliant.
Still Handles great