Z51 suspension questions
Thread Starter
Burning Brakes
Joined: Jun 2004
Posts: 1,164
Likes: 0
From: Edmond Ok
Z51 suspension questions
Hey all,
My 99 FRC shocks are starting to get worn, so Im looking into suspension upgrades when I do it. If I went with something like the Bilstien sport shocks, should I upgrade the sways at the same time? It handles pretty good now, but Im just trying to see if springs/sways are worth the price of the swap if you already have the z51.
Almost forgot... I do drag the car occasionally, I have yet to AutoX/road course it, however Im sure I eventually will. However for the most part, the car is driven normally, but will see some limited non-competition track use. Thanks,
Kap
My 99 FRC shocks are starting to get worn, so Im looking into suspension upgrades when I do it. If I went with something like the Bilstien sport shocks, should I upgrade the sways at the same time? It handles pretty good now, but Im just trying to see if springs/sways are worth the price of the swap if you already have the z51.
Almost forgot... I do drag the car occasionally, I have yet to AutoX/road course it, however Im sure I eventually will. However for the most part, the car is driven normally, but will see some limited non-competition track use. Thanks,
Kap
Race Director
Joined: Jun 2000
Posts: 13,733
Likes: 66
From: Hurst, TX USA
If you have the base suspension going to Z51 (or even better Z06) bars and springs is definately worth it. If you already have Z51 going to Z06 will not buy you much. Of course you could always go from Z51 to a racing suspension but those are pricy and a bit harsh in normal driving.
Melting Slicks
Joined: Jan 2004
Posts: 3,138
Likes: 37
From: Burbank. CA.
I put on 04 Z06 shocks. Much better over bumps when racing around corners. Smooth corners makes no difference. I like the stock sway-bars. Good balance. The car is stiffer with those shocks. I have a 99FRC too.
Le Mans Master
Joined: Dec 2000
Posts: 9,918
Likes: 1,880
From: Hot Springs AR
Leave the Z51 stuff alone, the Bilsteins are a bit stiffer, but they won't necessarily make it handle any better than Z51 shocks. '04 Z06 shocks are the rage right now, so look into those as well. I have no idea how they compare to Z51 in ride quality, no one mentions that.
HTH, and have a good one,
Mike
HTH, and have a good one,
Mike
Race Director
Joined: May 2000
Posts: 17,101
Likes: 5
From: No more yankee my wankee, the Donger is tired!
Originally Posted by BigJoe
If you have the base suspension going to Z51 (or even better Z06) bars and springs is definately worth it. If you already have Z51 going to Z06 will not buy you much. Of course you could always go from Z51 to a racing suspension but those are pricy and a bit harsh in normal driving.
Safety Car
Joined: Jul 2004
Posts: 3,706
Likes: 2
From: Valrico Florida
Very interesting post. I also have a 99 FRC and the car handles great right now compared to my F-body with eibach pro-kit and revalved bilsteins. I purchased some BMR sway bars and plan to purchase some 04 Z06 shocks if my current shocks cant take the pounding of my new iron block going in. I have chased a few local Z06 guys around corners and it seems only due to horsepower they were able to slowly pull away. I think the 99/00 FRC's are a good bang for the buck and it only takes a few minor upgrades to get Z06 handling. Just looking back at my 01 SS with upgraded suspension including S/T 35mm sway and stock 19 mm sway in the rear. I was able to keep up with Z06's on local corners on the highway, but the fear of the rear coming around was always there. I can honestly say with the C5 you do not worry about that as much. Oh.. My old SS made crazy power so horsepower was not an issue.
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
ALL FRC's came with the Z51 suspension. To change to the Z set-up entails just changing the rear spring, (as the front is the same as the Z already), changing anti-roll bars and adding the '04 shocks. These changes will make a very noticeable difference in the cornering and handling department, etc but maybe only marginal in the drag racing area. These mods are not too expensive though, so if your looking to auto-x or for more of a flatter cornering ability, then go for it! 
Robert
Robert
Thread Starter
Burning Brakes
Joined: Jun 2004
Posts: 1,164
Likes: 0
From: Edmond Ok
Originally Posted by LoneStarFRC
ALL FRC's came with the Z51 suspension.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
When I changed over to the Z's anti-roll bars I noticed a nice difference. Of course getting rid of the run-craps was in itself a major improvement. 
Safety Car
Joined: Jul 2004
Posts: 3,706
Likes: 2
From: Valrico Florida
I think you will notice a big difference between the Z06 sways and the 99 FRC Z51 setup.. You ask why? According to GM the 99 FRC front sway bars were 25.4mm and the rear were 21.7mm. The 00 FRC's front sway bars were 28.6mm and the rear were 23.6mm. The Z06 sway bars are 30.0mm in the front and 23.6mm in the rear. You cant tell me going from 25.4mm to 30mm in the front and from 21.7mm to 23.6mm in the rear will not be noticeable.
Le Mans Master
Joined: Dec 2000
Posts: 9,918
Likes: 1,880
From: Hot Springs AR
Originally Posted by KapUSMC
Actually all the 99 FRC's had the Z51. Was an option in '00. ...
Sorry, but Z51 was standard on all FRCs. GM just decided to give everyone headaches by listing Z51 on some RPO code sheets, on others just the FE2 (I think) suspension, and both on others.And, I'll have to go against the significant differences everyone's seeing between Z51 and Z06 suspension. I think that folks see a difference going from a used Z51 suspension (shocks and bushings, mainly) and new Z06 suspension parts.
And, if what we're talking about is feel, hey, that's great! What I think about is the actual cornering ability of the car.
Have a good one,
Mike
Safety Car
Joined: Jul 2004
Posts: 3,706
Likes: 2
From: Valrico Florida
Originally Posted by VetteDrmr
Sorry, but Z51 was standard on all FRCs. GM just decided to give everyone headaches by listing Z51 on some RPO code sheets, on others just the FE2 (I think) suspension, and both on others.And, I'll have to go against the significant differences everyone's seeing between Z51 and Z06 suspension. I think that folks see a difference going from a used Z51 suspension (shocks and bushings, mainly) and new Z06 suspension parts.
And, if what we're talking about is feel, hey, that's great! What I think about is the actual cornering ability of the car.
Have a good one,
Mike
Thread Starter
Burning Brakes
Joined: Jun 2004
Posts: 1,164
Likes: 0
From: Edmond Ok
Originally Posted by Vince99FRC
I think you will notice a big difference between the Z06 sways and the 99 FRC Z51 setup.. You ask why? According to GM the 99 FRC front sway bars were 25.4mm and the rear were 21.7mm. The 00 FRC's front sway bars were 28.6mm and the rear were 23.6mm. The Z06 sway bars are 30.0mm in the front and 23.6mm in the rear. You cant tell me going from 25.4mm to 30mm in the front and from 21.7mm to 23.6mm in the rear will not be noticeable.
Safety Car
Joined: Jul 2004
Posts: 3,706
Likes: 2
From: Valrico Florida
Originally Posted by KapUSMC
Vince, thanks for the diameters... I didnt realize the difference in sway sizes between 99 and 00 was that big.
Melting Slicks
Joined: Jan 2004
Posts: 3,138
Likes: 37
From: Burbank. CA.
Originally Posted by Vince99FRC
I think you will notice a big difference between the Z06 sways and the 99 FRC Z51 setup.. You ask why? According to GM the 99 FRC front sway bars were 25.4mm and the rear were 21.7mm. The 00 FRC's front sway bars were 28.6mm and the rear were 23.6mm. The Z06 sway bars are 30.0mm in the front and 23.6mm in the rear. You cant tell me going from 25.4mm to 30mm in the front and from 21.7mm to 23.6mm in the rear will not be noticeable.
Safety Car
Joined: Jul 2004
Posts: 3,706
Likes: 2
From: Valrico Florida
Originally Posted by mountainbiker2
I think it will be noticeable with more front end understeer. The difference between the front and rear size are much more with the Z06 sways. The Z06 has a stiffer rear spring which would make that end slide more. So GM put on a fatter swaybar in the front to compensate for that.
I agree
