coilover spring rate/length
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 810
Likes: 4
From: Austria
coilover spring rate/length
Hi all
have a question about spring rate/spring length/ ride height
it seems to be a well accepted setup on the C4 with 400lbs/10" springs front and 275lbs/10" springs rear, ZR1 425lbs/10" front
friend of mine runs the first setup on his C4, the threaded collar in the front is about in the middle, the collar back in the upper quarter of the threaded sleeve, and the car still sits rather a bit low
i want to upgrade to a coilover setup, mainly to restore (leaf springs are 25 years now) and of course, upgrade ride quality and level the car.
my question is, should i try 12" springs in the rear, i want a near stock, maybe a bit lower ride height and still have room for adjustments..
maybe its just a brain bug, but i like things that can be adjusted to hoover around a center..
thank you
have a question about spring rate/spring length/ ride height
it seems to be a well accepted setup on the C4 with 400lbs/10" springs front and 275lbs/10" springs rear, ZR1 425lbs/10" front
friend of mine runs the first setup on his C4, the threaded collar in the front is about in the middle, the collar back in the upper quarter of the threaded sleeve, and the car still sits rather a bit low
i want to upgrade to a coilover setup, mainly to restore (leaf springs are 25 years now) and of course, upgrade ride quality and level the car.
my question is, should i try 12" springs in the rear, i want a near stock, maybe a bit lower ride height and still have room for adjustments..
maybe its just a brain bug, but i like things that can be adjusted to hoover around a center..
thank you
Team Owner
Joined: Sep 2003
Posts: 25,365
Likes: 2,731
The branding of the coil-over shock will generally require a specific spring height. I'd suggest not deviating from that. Rates for sure can vary widely and I don't believe the rates you mention could be considered "gospel". Rates would be very dependent on the use of the car. A coupe or a 'vert?
The length of the threaded sleeve and the placement of the snap-ring locating it is likely what is responsible for the "visual" on your friends car if it's done with modified Bilstein product. Some coil-over product is supplied with shocks already threaded.
The length of the threaded sleeve and the placement of the snap-ring locating it is likely what is responsible for the "visual" on your friends car if it's done with modified Bilstein product. Some coil-over product is supplied with shocks already threaded.
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 810
Likes: 4
From: Austria
The branding of the coil-over shock will generally require a specific spring height. I'd suggest not deviating from that. Rates for sure can vary widely and I don't believe the rates you mention could be considered "gospel". Rates would be very dependent on the use of the car. A coupe or a 'vert?
The length of the threaded sleeve and the placement of the snap-ring locating it is likely what is responsible for the "visual" on your friends car if it's done with modified Bilstein product. Some coil-over product is supplied with shocks already threaded.
The length of the threaded sleeve and the placement of the snap-ring locating it is likely what is responsible for the "visual" on your friends car if it's done with modified Bilstein product. Some coil-over product is supplied with shocks already threaded.
you are right, modified bilsteins, the thread sleeve sits about 1" above the lower shock end.
car is a coupe!
im also with you, that the rates are tested and proven to work, so i wont alter that.
i also want to use my Bilsteins, as i haven them overhauled a time ago...and would overhaul them again if necessary
thank you!
Team Owner
Joined: Sep 2003
Posts: 25,365
Likes: 2,731
Hi Dave!
you are right, modified bilsteins, the thread sleeve sits about 1" above the lower shock end.
car is a coupe!
im also with you, that the rates are tested and proven to work, so i wont alter that.
i also want to use my Bilsteins, as i haven them overhauled a time ago...and would overhaul them again if necessary
thank you!
you are right, modified bilsteins, the thread sleeve sits about 1" above the lower shock end.
car is a coupe!
im also with you, that the rates are tested and proven to work, so i wont alter that.
i also want to use my Bilsteins, as i haven them overhauled a time ago...and would overhaul them again if necessary
thank you!
How go things?
I have a set of these that are very low miles and I don't recall the spring rates but I've considered selling them recently and likely just doing my FX3 shocks for the same package. If these might interest you send me an email and I'll check the spring rates.
I believe maybe you'd just require the sleeves and hardware so maybe you wouldn't use the typical branding used here. You might even have a wider variety of options than we do. I believe you can do your own "grooving" for the sleeve snap-ring, I'd think the proper I.D. sleeve is likely available also. You could likely assemble the needed parts locally and not be interested in my package.
If you need any information drop me an email!
Last edited by WVZR-1; Oct 10, 2015 at 08:22 AM.
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
I changed the rear spring mounting and use 8" springs, but my car also sits low. I'm useing 450lbs/10" springs front and ~350lbs/8" springs rear. The rear springs are too stiff and I'm planing on changing them to something around 300lbs/8". The front springs are great IMO.
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 810
Likes: 4
From: Austria
I changed the rear spring mounting and use 8" springs, but my car also sits low. I'm useing 450lbs/10" springs front and ~350lbs/8" springs rear. The rear springs are too stiff and I'm planing on changing them to something around 300lbs/8". The front springs are great IMO.
i plan using 425 in front like the ZR1, as my engine is heavier than stock..
regards
Team Owner
Joined: Sep 2003
Posts: 25,365
Likes: 2,731
I changed the rear spring mounting and use 8" springs, but my car also sits low. I'm useing 450lbs/10" springs front and ~350lbs/8" springs rear. The rear springs are too stiff and I'm planing on changing them to something around 300lbs/8". The front springs are great IMO.
It would seem that to use an 8" coil height you would need some "specialty" shocks. You didn't mention what you've got so if you've other than OE maybe the set-up is correct with an 8" spring height. Do you have maybe QA1 or an older Carrera package maybe?
When we did our first coil-overs there wasn't the luxury of the Internet and research was much more difficult. It was often a "for hire" project and you used what was the result of someone else's calculations. It wasn't for a C4 Corvette.
Last edited by WVZR-1; Oct 10, 2015 at 04:43 PM.
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
WVZR-1 other then the rear shock mounts this is the page I used, and have said it before. http://www.ndneyes.com/page5.html
The lower mounts, I'm using these. It was not adjusted when I took this picture.
PS
It corners far better then it did with the mono-leaf. I have not hooked up the front sway-bar, and IMO it was better before re-connecting the rear.
The lower mounts, I'm using these. It was not adjusted when I took this picture.
PS
It corners far better then it did with the mono-leaf. I have not hooked up the front sway-bar, and IMO it was better before re-connecting the rear.
Last edited by aDigitalPhantom; Oct 11, 2015 at 10:04 AM.
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Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 810
Likes: 4
From: Austria
WVZR-1 other then the rear shock mounts this is the page I used, and have said it before. http://www.ndneyes.com/page5.html
The lower mounts, I'm using these. It was not adjusted when I took this picture.
PS
It corners far better then it did with the mono-leaf. I have not hooked up the front sway-bar, and IMO it was better before re-connecting the rear.
The lower mounts, I'm using these. It was not adjusted when I took this picture.
PS
It corners far better then it did with the mono-leaf. I have not hooked up the front sway-bar, and IMO it was better before re-connecting the rear.
you also changed the axis of possible shock movements...transversal now vs longitudinal stock...