Suspension Settings - ZR-1 Net Registry Forums

Billy Mild · 09-10-2014

It seems on this car that the suspension doesn't seem very tight. The car does seem to flex a lot, and I noticed it is really bad when the roof is out. Is this typical of the C4? My 86 951 was pretty stiff chassis and with a refreshed suspension handled decent, but still had some body roll.

On the ZR1 when I have the car in touring mode it just seems to bounce around a lot and be floating on air. With the suspension firmed up a bit that feeling goes away, but the chassis still seems to flex a bit. I think 90% of the rattles and creaks are from the chassis flexing so much. Are there any fixes for that, or is this caused by bad suspension bushings? How often do the shocks need to be rebuilt?

Harvie · 09-10-2014

Weld a roll bar in right behind the seats. Bar stiffens up the frame.

Kevin · 09-10-2014

Quote:

Originally Posted by Billy Mild

It seems on this car that the suspension doesn't seem very tight. The car does seem to flex a lot, and I noticed it is really bad when the roof is out. Is this typical of the C4? My 86 951 was pretty stiff chassis and with a refreshed suspension handled decent, but still had some body roll.

On the ZR1 when I have the car in touring mode it just seems to bounce around a lot and be floating on air. With the suspension firmed up a bit that feeling goes away, but the chassis still seems to flex a bit. I think 90% of the rattles and creaks are from the chassis flexing so much. Are there any fixes for that, or is this caused by bad suspension bushings? How often do the shocks need to be rebuilt?

Have this same issue, of course PA roads are rubbish

Z06scentair · 09-10-2014

Typical C4 complaints and is the main reason I never romove the roof panel on them.

The C5 FRC/z06 is my favorite ride/handling car of all corvette's. The fixed roof makes them feel so tight yet quick on their toes.

mike100 · 09-10-2014

the roof panel is critical. I had a cracking clear plastic top and once replaced, it felt like a whole new car. Along those lines, the FX3 adjustable shocks feel a lot better after a rebuild, especially if you valve them with more rebound damping. I never drive in the soft modes- it will crash to the bumpstops over speed bumps just about when going real slow. Another option might be to get a reprogrammed fx3 shock controller than adjusts them stiffer at lower speeds. My shocks had 27k miles on them and absolutely sucked, but felt great after rebuilding. Bilstein doesn't really want to support these shocks anymore though as their prices are through the roof.

I have also installed the DRM rear trailing arm bracket which affects the anti-squat and seems to have reduced the nose down pitching under braking too. Raising the front end to stock ride height also helped preload the front spring to a stiffer initial tension and gives the shocks a bit more time to damp movement before bottoming out. All these small changes really makes it a pleasure to drive hard and it doesn't feel like a bloated tuna boat anymore.

We Gone · 09-10-2014

Sounds completely normal, I leave mine on sport or performance..tour is to soft . Never take the top off.

Kevin · 09-10-2014

Quote:

Originally Posted by We Gone

Sounds completely normal, I leave mine on sport or performance..tour is to soft . Never take the top off.

Unless you have one of the Targa Truses. Would love to get one of them

batchman · 09-10-2014

I come from the land of topless Mustangs so with the roof on the car doesn't seem too bad to me

.

The spring/shock/bar package from the factory is all "touring" however. Doubling the spring rates (with shocks to match) is a start, and doesn't kill the ride. I was really really surprised that an option package as spendy as this did not get the very good Z51 stuff.

Cheers,
- Jeff

Meanmyz · 09-10-2014

I haven't read everybody's post in this thread, but it sounds like you need to check out the thread's on the new frame stiffening product. It was designed by Gordon Killebrew.

Here's a thread on the subject: http://www.zr1.net/forum/showthread....rame+stiffener

That and some revalved shocks might make you really happy!

Kevin · 09-10-2014

Quote:

Originally Posted by Meanmyz

I haven't read everybody's post in this thread, but it sounds like you need to check out the thread's on the new frame stiffening product. It was designed by Gordon Killebrew.

Here's a thread on the subject: http://www.zr1.net/forum/showthread....rame+stiffener

That and some revalved shocks might make you really happy!

just bought that set up, haven't put it on, but I drove David's car with it and had to buy one. Makes a huge difference

09-10-2014	#1
Billy Mild Join Date: Aug 2014 Location: Kansas City, MO Posts: 838	Suspension Settings It seems on this car that the suspension doesn't seem very tight. The car does seem to flex a lot, and I noticed it is really bad when the roof is out. Is this typical of the C4? My 86 951 was pretty stiff chassis and with a refreshed suspension handled decent, but still had some body roll. On the ZR1 when I have the car in touring mode it just seems to bounce around a lot and be floating on air. With the suspension firmed up a bit that feeling goes away, but the chassis still seems to flex a bit. I think 90% of the rattles and creaks are from the chassis flexing so much. Are there any fixes for that, or is this caused by bad suspension bushings? How often do the shocks need to be rebuilt? __________________ Looking for a ZR-1 1985 Yamaha RZ350-NOT STOCK 1971 Yamaha AT1-Middle of a restoration

09-10-2014	#2
Harvie Join Date: Aug 2014 Location: In my house Posts: 103	Re: Suspension Settings Weld a roll bar in right behind the seats. Bar stiffens up the frame. __________________ Charter Member (since the 91) of the 1ST ZR1 Registry 1st vet $157.59. mo for 3 years new 2nd new 1 check & STILL eating funds years later [-X show poodles & trailer queens :-({\|= Fast and fun not pretty in pink.

09-10-2014	#4
Z06scentair Join Date: Sep 2013 Location: Charlotte NC Posts: 655	Re: Suspension Settings Typical C4 complaints and is the main reason I never romove the roof panel on them. The C5 FRC/z06 is my favorite ride/handling car of all corvette's. The fixed roof makes them feel so tight yet quick on their toes. Last edited by Z06scentair; 09-10-2014 at 08:56 PM.

09-10-2014	#5
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,802	Re: Suspension Settings the roof panel is critical. I had a cracking clear plastic top and once replaced, it felt like a whole new car. Along those lines, the FX3 adjustable shocks feel a lot better after a rebuild, especially if you valve them with more rebound damping. I never drive in the soft modes- it will crash to the bumpstops over speed bumps just about when going real slow. Another option might be to get a reprogrammed fx3 shock controller than adjusts them stiffer at lower speeds. My shocks had 27k miles on them and absolutely sucked, but felt great after rebuilding. Bilstein doesn't really want to support these shocks anymore though as their prices are through the roof. I have also installed the DRM rear trailing arm bracket which affects the anti-squat and seems to have reduced the nose down pitching under braking too. Raising the front end to stock ride height also helped preload the front spring to a stiffer initial tension and gives the shocks a bit more time to damp movement before bottoming out. All these small changes really makes it a pleasure to drive hard and it doesn't feel like a bloated tuna boat anymore. Last edited by mike100; 09-10-2014 at 03:54 PM.

09-10-2014	#6
We Gone Join Date: Apr 2004 Location: ATL. GA. Posts: 2,162	Re: Suspension Settings Sounds completely normal, I leave mine on sport or performance..tour is to soft . Never take the top off. __________________ Steve 1990 Steel Blue/Black #2355 1990 Red/Red #1473 1991 Quasar /Black #118 Sold 1991 Turquoise/Black #766 Parted Out 1993 Yellow/White #179 Sold 1990 Black/Gray #1361 Headers/4:10s Sold

09-10-2014	#8
batchman Join Date: Jun 2009 Location: I live at Devens, one run at a time Posts: 455	Re: Suspension Settings I come from the land of topless Mustangs so with the roof on the car doesn't seem too bad to me . The spring/shock/bar package from the factory is all "touring" however. Doubling the spring rates (with shocks to match) is a start, and doesn't kill the ride. I was really really surprised that an option package as spendy as this did not get the very good Z51 stuff. Cheers, - Jeff __________________ [I]91 ZR-1 #1840, autocrossing in SCCA BSP. FIC S/S's DRM chip/Watson/Borla/lid/LW batt&headlights, springs, shocks, pads & lines, quick rack & Turn One, camber brace, 32/22mm sways, A/C halfway deleted 17x11 & 12 CCW's, 315 & 335 Hoosier A6s [/I]

09-10-2014	#9
Meanmyz Join Date: Feb 2006 Location: Springfield, Minnesota Posts: 444	Re: Suspension Settings I haven't read everybody's post in this thread, but it sounds like you need to check out the thread's on the new frame stiffening product. It was designed by Gordon Killebrew. Here's a thread on the subject: http://www.zr1.net/forum/showthread....rame+stiffener That and some revalved shocks might make you really happy!