C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Coilover Spring Rates?

Thread Tools
 
Search this Thread
 
Old Nov 23, 2013 | 08:19 PM
  #1  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default Coilover Spring Rates?

I just bought a set of Qa1 coilovers from a forum member and I am trying to decide if I want to stay with the spring rate that is on them or if I should change them up. My car is going to be mainly ran on the street but it will see the autox track and strip alot also.

The QA1 springs are 10-250 which from what I see have the spring rate of 250 lbs. That seems a little light to me but I have never ran coilovers on a C4. From the research I have do thus far, these should have heavier springs on the front. In the pictures they appear to have the same springs on all 4.

Any input would be great guys.



http://www.qa1.net/qa1_motorsports/c...d-springs.html
Reply
Old Nov 23, 2013 | 09:57 PM
  #2  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
Default

I'd guess those are extremely "light" at maybe all fours - I believe that most L98/LT1 cars throughout the forum are probably at 400 for the fronts and maybe the majority of the rears maybe at 350. There's a good bit that goes into the calculation of the effective rate. The angle of the mount has considerable to do with that.

I'm not recommending the weights I mentioned but you need to check into it considerably before I guess an install. It looks like you also are going to need 2 more spanner nuts. Your rears look to be missing the jamb nuts.

There were some very interesting threads 5 - 6 years ago and most are likely still around by just searching.

Here's a good read from Hyperco:

http://www.hypercoils.com/spring-rate-calculator/


These may or may not work:

http://www.proshocks.com/calcs/

There are many others. I'd start with getting the springs you have checked for "rate" - simple and you should be able to get it accomplished local for cheap or maybe even "free"!

Last edited by WVZR-1; Nov 23, 2013 at 10:07 PM.
Reply
Old Nov 23, 2013 | 10:16 PM
  #3  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default

Originally Posted by WVZR-1
I'd guess those are extremely "light" at maybe all fours - I believe that most L98/LT1 cars throughout the forum are probably at 400 for the fronts and maybe the majority of the rears maybe at 350. There's a good bit that goes into the calculation of the effective rate. The angle of the mount has considerable to do with that.

I'm not recommending the weights I mentioned but you need to check into it considerably before I guess an install. It looks like you also are going to need 2 more spanner nuts. Your rears look to be missing the jamb nuts.

There were some very interesting threads 5 - 6 years ago and most are likely still around by just searching.

Here's a good read from Hyperco:

http://www.hypercoils.com/spring-rate-calculator/


These may or may not work:

http://www.proshocks.com/calcs/

There are many others. I'd start with getting the springs you have checked for "rate" - simple and you should be able to get it accomplished local for cheap or maybe even "free"!
Very Interesting!

Looks like I have alot to learn on the suspension of this car. I t will be a total removal ,clean up, powdercoat, and replace project over the winter.

Thanks BTW!

Last edited by smooth1990; Nov 23, 2013 at 10:21 PM.
Reply
Old Nov 24, 2013 | 10:15 AM
  #4  
armysnipe's Avatar
armysnipe
Racer
Supporting Member
15 Year Member
Liked
 
Joined: Jun 2010
Posts: 365
Likes: 27
From: Shelby Township Michigan
Default

I have the Van Steel kit on my 93 coupe with 500# on the front and 425# on the rear. They are a little bouncy on the street, but with stock seats and neoprene seat covers tolerable. If I had race seats I don't think I could drive on the street and be comfortable. However, the streets here in metro Detroit suck. The setup did allow me to go from the street to the drag strip to a road track with no suspension adjustments. Also, note I have a 32 MM front sway bar and SPC adjustable upper control arms. In the rear I'm still running the stock sway bar which IMO is fine. I also run banksi rod ends in the rear with all poly bushings. It's definitely a race car driven on the street. The SPC control arms allow you to have an aggressive alignment and still drive on the street.

So, maybe contact Van Steel. They are very knowledgeable with spring rates. With my set up
The ride is smooth or rough depending on the road.
Reply
Old Nov 24, 2013 | 10:23 AM
  #5  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default

Originally Posted by armysnipe
I have the Van Steel kit on my 93 coupe with 500# on the front and 425# on the rear. They are a little bouncy on the street, but with stock seats and neoprene seat covers tolerable. If I had race seats I don't think I could drive on the street and be comfortable. However, the streets here in metro Detroit suck. The setup did allow me to go from the street to the drag strip to a road track with no suspension adjustments. Also, note I have a 32 MM front sway bar and SPC adjustable upper control arms. In the rear I'm still running the stock sway bar which IMO is fine. I also run banksi rod ends in the rear with all poly bushings. It's definitely a race car driven on the street. The SPC control arms allow you to have an aggressive alignment and still drive on the street.

So, maybe contact Van Steel. They are very knowledgeable with spring rates. With my set up
The ride is smooth or rough depending on the road.
500 is the raw spring weight? Why do you think someone had 250s all the way around on this set up? That seems extremely light. Looks like I will be ordering spring..
Reply
Old Nov 24, 2013 | 10:39 AM
  #6  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
Default

Originally Posted by smooth1990
500 is the raw spring weight? Why do you think someone had 250s all the way around on this set up? That seems extremely light. Looks like I will be ordering spring..
I'm quite sure all anyone could post would be the "advertised" rate. I'm assuming that's what you're calling "raw"! Do you actually know what the package that you have was assembled for? I doubt it was actually assembled for a "fully optioned" C4 build. Maybe resto-rod of sorts with C4 suspension. See what "Mongoose" uses or suggests with their package on the GS.

http://www.mongoosems.com/

That is what I assumed they were for starters and here's a thread from a few months ago showing the "jamb nuts" I believe you're missing.

http://forums.corvetteforum.com/c4-t...fferences.html

Use the information I posted yesterday for you to "convert" the weights or maybe and I would think "Armysnipe" likely has. I expect he'll be back!
Reply
Old Nov 24, 2013 | 10:43 AM
  #7  
armysnipe's Avatar
armysnipe
Racer
Supporting Member
15 Year Member
Liked
 
Joined: Jun 2010
Posts: 365
Likes: 27
From: Shelby Township Michigan
Default

I'm not sure and won't pretend that I know. That's why I suggested calling Van Steel. My receipt from Van Steel says Front K=500 and Rear K=425 if it helps.
Reply
Old Nov 24, 2013 | 10:55 AM
  #8  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
Default

Originally Posted by armysnipe
I'm not sure and won't pretend that I know. That's why I suggested calling Van Steel. My receipt from Van Steel says Front K=500 and Rear K=425 if it helps.
That is the way I believe Van Steel and VBP product is flagged. Yours is assembled and driving so you can't easily check but it would be etched in the end of each coil.

I have a set of EM/DRM with 10" Hyperco and the fronts are 400 and the rears 275 (on the spring).

OP - if these would interest you we could discuss maybe a swap of sorts. The shocks with mine are very low use and they're already cut for the ring etc. I don't recall the Bilstein #'s but I could check probably. I would need the Bilstein #'s on yours etc.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Nov 24, 2013 | 11:00 AM
  #9  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default

Originally Posted by WVZR-1
I'm quite sure all anyone could post would be the "advertised" rate. I'm assuming that's what you're calling "raw"! Do you actually know what the package that you have was assembled for? I doubt it was actually assembled for a "fully optioned" C4 build. Maybe resto-rod of sorts with C4 suspension. See what "Mongoose" uses or suggests with their package on the GS.

http://www.mongoosems.com/

That is what I assumed they were for starters and here's a thread from a few months ago showing the "jamb nuts" I believe you're missing.

http://forums.corvetteforum.com/c4-t...fferences.html

Use the information I posted yesterday for you to "convert" the weights or maybe and I would think "Armysnipe" likely has. I expect he'll be back!
Looks like you are spot on WVZR-1!

I emailed mongoose to see what they suggest. i didnt see any jam nuts on their site but they hopefully have some they can sell me.

I should have done more research on these before I bought them. Looks like with all the replacement stuff and changes, I will be into them for as much as a new set from EM.
Reply
Old Nov 24, 2013 | 11:19 AM
  #10  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
Default

Originally Posted by smooth1990
Looks like you are spot on WVZR-1!

I emailed mongoose to see what they suggest. i didnt see any jam nuts on their site but they hopefully have some they can sell me.

I should have done more research on these before I bought them. Looks like with all the replacement stuff and changes, I will be into them for as much as a new set from EM.
Let's back up here a bit and you recall I suggested you get yours checked "locally" - I still think that wise BUT let's suppose this - the springs are sold as 10 - 250 "because" the 250 is an equivalent "metric" measurement and you still need to check the ends of the coils for weights.

10" = 254mm Yours are on the floor check the ends of the coils! It will be an interesting find I believe!

I didn't mean for you to ask for a recommendation from Mongoose but it shouldn't hurt. I just meant to ask what they suggest for their GS/replica/resto-rod package when you buy their product.

Last edited by WVZR-1; Nov 24, 2013 at 11:40 AM.
Reply
Old Nov 24, 2013 | 11:41 AM
  #11  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default

Originally Posted by WVZR-1
That is the way I believe Van Steel and VBP product is flagged. Yours is assembled and driving so you can't easily check but it would be etched in the end of each coil.

I have a set of EM/DRM with 10" Hyperco and the fronts are 400 and the rears 275 (on the spring).

OP - if these would interest you we could discuss maybe a swap of sorts. The shocks with mine are very low use and they're already cut for the ring etc. I don't recall the Bilstein #'s but I could check probably. I would need the Bilstein #'s on yours etc.
Ok. I was under the impression that the 10-250 meant it was a 10' coil with a spring rate of 250. Atleast thats what I got out of the QA1 website.

http://www.qa1.net/qa1_motorsports/c...d-springs.html

I will check the ends of the springs when they arrive from the person I purchased them from.

What setup do you have and why would you be interested in swapping? Either way I need to get the right setup on my car before they are installed the first time so I am open to ideas. Springs, if i have to change them are going to run 170.00 or so. I would think I would want to get the shocks rebuilt and revalved also.
Reply
Old Nov 24, 2013 | 03:16 PM
  #12  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
Default

Originally Posted by smooth1990
Ok. I was under the impression that the 10-250 meant it was a 10' coil with a spring rate of 250. Atleast thats what I got out of the QA1 website.
I would have assumed and did that the 10 -250 meant precisely that but there's not many applications that would do the 250 X 4 - I was attempting to rethink the package. I thought you would have had these in hand.
Reply
Old Nov 24, 2013 | 04:09 PM
  #13  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default

Originally Posted by WVZR-1
I would have assumed and did that the 10 -250 meant precisely that but there's not many applications that would do the 250 X 4 - I was attempting to rethink the package. I thought you would have had these in hand.

I should have them wendsday.

I meassured my fx3 rod and it came out to 14mm or .550. Im wondering if these will fit my fx3 shock.....
Reply
Old Nov 27, 2013 | 12:16 PM
  #14  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default

Looks Like I will beable to retain my FX3 with this coilover setup. I did a little mocking up this morning and here is what it looks like!

Dont mind the dirt! Im in the process of a complete suspension rebuild so she will look all purty when its done!





Reply
Old Jan 4, 2014 | 11:19 AM
  #15  
catchme76's Avatar
catchme76
Pro
20 Year Member
 
Joined: Oct 2003
Posts: 572
Likes: 1
From: MOBILE Al
Default

I did a double take as I ran across this thread! I am selling the same coilovers from my Grand Sport as I just went to ridetech triple adjustables.

Did you buy these from Larry?
Reply
Old Jan 5, 2014 | 01:42 PM
  #16  
BrianCunningham's Avatar
BrianCunningham
Team Owner
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2001
Posts: 30,856
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Default

Like I said in your other thread

Give Doug Rippie a call, they'll set you up with proper springs

http://forums.corvetteforum.com/c4-t...le-shocks.html
Reply
Old Jan 5, 2014 | 02:00 PM
  #17  
catchme76's Avatar
catchme76
Pro
20 Year Member
 
Joined: Oct 2003
Posts: 572
Likes: 1
From: MOBILE Al
Default

Or calculate the spring rates yourself.. Hyperco will suggest a slightly higher rate spring, but it doesn't take into account streetability. Ridetech will offer 3 seperate spring rate choices to fit your needs.

I have all the measurements for my 96 vette suspension if you need them. The only thing that may be different is your coil angle. I bought a $1.50 protractor from CVS to get my angle.

Several extremely succesful racers and vendors said to go with a hyperco spring over a QA-1.. They win all the time, so I took their advice.

http://www.ridetech.com/tech/spring-rate-calculator/


http://www.hypercoils.com/spring-rate-calculator/
Reply

Get notified of new replies

To Coilover Spring Rates?





All times are GMT -4. The time now is 04:58 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE