Coilover mountings - are they man enough?
Thread Starter
Intermediate
Joined: Sep 2006
Posts: 39
Likes: 0
From: Harlington Bedfordshire
Coilover mountings - are they man enough?
I have just acquired a nice 95 C4 black on black convertible here in England, low mileage (35,000) and therefore possible suffering from lack of use. As a result I am still getting used to it. Please forgive any repetition of previous postings for the following.....
The suspension (standard) is quite hard and on our sometimes uneven road surfaces, the front (and back) will suddenly leap sideways. Fine in the dry, not so funny in our wet climate. I read about conversion to coilover to enable a softer suspension and programmable damping, and have seen various arguments for and against. I understand that in such a conversion the existing mountings for the shock adsorbers are used to mount the coilover units. The question is are they man enough? Is there a lot of experience of these conversions that enable one to have confidence in these existing mountings, or are the cars that are converted trashed in competitive events before the effects of fatigue cracking show themselves.
Advice would be much appreciated.
The suspension (standard) is quite hard and on our sometimes uneven road surfaces, the front (and back) will suddenly leap sideways. Fine in the dry, not so funny in our wet climate. I read about conversion to coilover to enable a softer suspension and programmable damping, and have seen various arguments for and against. I understand that in such a conversion the existing mountings for the shock adsorbers are used to mount the coilover units. The question is are they man enough? Is there a lot of experience of these conversions that enable one to have confidence in these existing mountings, or are the cars that are converted trashed in competitive events before the effects of fatigue cracking show themselves.
Advice would be much appreciated.
Team Owner
Joined: Sep 2003
Posts: 20,179
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
What your describing sounds like shocks that have seen their better days.
Not having any experience with coil-overs..... May I suggest that you first replace your shocks with a good replacement like Koni or QA-1?
These brands offer adjustments not found on ordinary shocks and may solve your problems without the investment in suspension mods.
Not having any experience with coil-overs..... May I suggest that you first replace your shocks with a good replacement like Koni or QA-1?
These brands offer adjustments not found on ordinary shocks and may solve your problems without the investment in suspension mods.
Thread Starter
Intermediate
Joined: Sep 2006
Posts: 39
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From: Harlington Bedfordshire
I think you may have hit the nail on the head. I also believe that the shocks are less than perfect as the car does not like gently undulating road surface either.
Any particular model shock from the ranges suggested? The car is a convertible.
Also I have heard that American damping is biassed towards damping the rebound whereas in Europe I gather we tend to bias the damping towards the bounce, and that by fitting European dampers the handling can be worsened. Any comments and advice much appreciated.
Any particular model shock from the ranges suggested? The car is a convertible.
Also I have heard that American damping is biassed towards damping the rebound whereas in Europe I gather we tend to bias the damping towards the bounce, and that by fitting European dampers the handling can be worsened. Any comments and advice much appreciated.
Racer
Joined: Nov 2004
Posts: 445
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Replacement shock absorbers seem to be definitely in order here...From what I have read, the adjustable Koni's and QA1's seem to be up there.
I have early adj.Koni's on my 87 and am happy with them.
As you drive the car more, esp. if it is spirited driving, you may find that it feels soft and bouncy. You seem to have noticed some of this already on undulating surfaces.
There is a simple and cost effective fix for this...heavier anti-sway bars.
You probably have a 26mm fr. and 22mm rear bar currently.
If you change to a 30 fr. and 25/6 rear the change in handling characteristics will be pleasantly apparent.
If things are still too soft and feel vague, then a spring up-grade will help..
I have driven many vettes, some with Z51/2 suspension and others with base (like your roadster), and the difference between cars is huge...IMO base cars need tightening.
I have done the the above, and can say that I have a reasonably good handling car, esp. considering its weight and transverse spring design.
I do not, however, have any experience with coil-overs. In fact, living in Australia I have only just recently seen a c/overed vette...looked impressive, too..!
Take a look at VBandP's site...plenty of goodies on the subject there..
I have early adj.Koni's on my 87 and am happy with them.
As you drive the car more, esp. if it is spirited driving, you may find that it feels soft and bouncy. You seem to have noticed some of this already on undulating surfaces.
There is a simple and cost effective fix for this...heavier anti-sway bars.
You probably have a 26mm fr. and 22mm rear bar currently.
If you change to a 30 fr. and 25/6 rear the change in handling characteristics will be pleasantly apparent.
If things are still too soft and feel vague, then a spring up-grade will help..
I have driven many vettes, some with Z51/2 suspension and others with base (like your roadster), and the difference between cars is huge...IMO base cars need tightening.
I have done the the above, and can say that I have a reasonably good handling car, esp. considering its weight and transverse spring design.
I do not, however, have any experience with coil-overs. In fact, living in Australia I have only just recently seen a c/overed vette...looked impressive, too..!
Take a look at VBandP's site...plenty of goodies on the subject there..
Melting Slicks
Joined: Oct 2003
Posts: 2,951
Likes: 3
From: Mount Vernon OH
Coilovers
I am doing the QA1 coilover conversion right now. I should have some decent photos by Monday or Tuesday of next week. The coilovers I bought you can adjust your ride height with different springs so if you are looking for the slamed effect it is pretty easy to do. My main goal was weight reduction and since I have pulled so much weight out of the car and especially the front end I knew the nose would be pretty high if I didn't do something. The cost for the shocks and hardware was about $450. Good luck whichever way you go.
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Le Mans Master
Joined: Aug 2002
Posts: 6,080
Likes: 3
From: Clearwater FL
St. Jude Donor '06
If you are looking into a softer ride, I'd go with a set of the base FE1 comfort ride Biltsein shocks. Do you know what suspension option the car came with from the factory?
Safety Car
Joined: Sep 2003
Posts: 3,692
Likes: 5
From: Hayward CA
Originally Posted by JAYK
shock mounts are more than strong enough and you can put a kit together using spax coilovers
Do you have the part numbers for your spax kit? I've seen your setup and I'm very interested in it.
Team Owner
Joined: Sep 2003
Posts: 25,295
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From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
Melting Slicks
Joined: Oct 2003
Posts: 2,951
Likes: 3
From: Mount Vernon OH
Coilovers
Originally Posted by opel
NitrousSam, I was under the impression that the front shock mounts on the early C4's would not hold up to the coilovers?
Dave
Dave
Melting Slicks
Joined: Oct 2003
Posts: 2,951
Likes: 3
From: Mount Vernon OH
Originally Posted by Kinkajou
When using coil overs do you keep the fiberglass spring / leaf?
Where do you suggest to get the sway bars?
Thanks
Where do you suggest to get the sway bars?
Thanks
Racer
Joined: Nov 2002
Posts: 478
Likes: 0
From: langhorne
I just replaced the FE1 stock bilsteins on my 95 with the Z51 bilstein shocks. I got them from Ecklers. They claim to be 20% stiffer than the original Z51's. my car is now much better balanced 
I highly recomend them. Before she danced all over the place. Now it's point and go!
I highly recomend them. Before she danced all over the place. Now it's point and go!