Rear Coilover Spring Rate Help

MROD7007 · 05-26-2021, 12:27 PM

Looking for advice on what spring rate would be best and why?

Details: Ladder Bar, Santhuff Double Adjustable on all 4, 150 springs on the front, 406, Glide, 1600lb. rear weight, 19" rear shock length. 1700lb front weight.

Mark

SSDiv6 · 05-26-2021, 12:49 PM

Quote:

Originally Posted by MROD7007

Looking for advice on what spring rate would be best and why?

Details: Ladder Bar, Santhuff Double Adjustable on all 4, 150 springs on the front, 406, Glide, 1600lb. rear weight, 19" rear shock length. 1700lb front weight.

Mark

Reach out to Marty Rinehart at Rinehart Performance. They sell and work with Santhuff on all kinds of combos.

MROD7007 · 05-26-2021, 07:06 PM

I have asked them and they recommend 125# and Santhuff had recommended a 150# spring along with a few others. However I want someone to explain why use a specific rate and how it should affect the car.

Marty Rinehart Jr · 05-26-2021, 10:09 PM

Mark. You’re car is gonna work just fine trust me!

Eman · 05-27-2021, 12:00 AM

There are good technical pages on the Chris Alston chassis site. Info on choosing spring rates and setting up coilovers.

Lenny5160 · 05-27-2021, 02:22 PM

Isn't the theory that you want the lightest spring that will hold the car up? That will most easily allow your ladder bar and shock adjustments to do their thing without unnecessary resistance from the springs.

SGSST109E · 05-27-2021, 09:18 PM

correct

MROD7007 · 05-27-2021, 10:12 PM

So your saying as long as the spring doesn’t coil bind and has enough room for compression for bumps that’s the best spring?

Adger Smith · 05-28-2021, 08:05 PM

What Lenny said ^^^^
Use the shock adjustment/valving for bumps..

CMcAllister · 05-28-2021, 10:16 PM

For any situation, there will be 3 or more spring rates which will support the car at the desired ride height with the shock at the the desired center to center (which should be maintained). This will have the different rate springs compressed to different heights. Compressing a spring stores energy which makes the suspension more "lively".

Heavy springs compressed a little will react differently than light springs compressed more. Which you use depends on many things in your combination and personal preference. Lighter springs will usually require better shocks to control the housing, especially with ladder bars, certain 4 link settings and/or higher power levels, allowing you to tune it accordingly.

Marty's recommendation of 125# on that 14" spring (I assume) and the Santhuffs is likely spot on.

05-26-2021, 12:27 PM	#1
MROD7007 Junior Member Join Date: Jul 2018 Posts: 9 Likes: 1 Liked 1 Time in 1 Post	Rear Coilover Spring Rate Help Looking for advice on what spring rate would be best and why? Details: Ladder Bar, Santhuff Double Adjustable on all 4, 150 springs on the front, 406, Glide, 1600lb. rear weight, 19" rear shock length. 1700lb front weight. Mark

05-26-2021, 07:06 PM	#3
MROD7007 Junior Member Join Date: Jul 2018 Posts: 9 Likes: 1 Liked 1 Time in 1 Post	Re: Rear Coilover Spring Rate Help I have asked them and they recommend 125# and Santhuff had recommended a 150# spring along with a few others. However I want someone to explain why use a specific rate and how it should affect the car.

05-26-2021, 10:09 PM	#4
Marty Rinehart Jr Member Join Date: Dec 2001 Location: Rineharts Performance Race Cars, Thomasville,PA Posts: 457 Likes: 228 Liked 228 Times in 51 Posts	Re: Rear Coilover Spring Rate Help Mark. You’re car is gonna work just fine trust me! __________________ Marty Rinehart Jr 1125 SS STK SG SC SST

05-27-2021, 12:00 AM	#5
Eman Member Join Date: May 2014 Location: E TN Posts: 455 Likes: 14 Liked 116 Times in 67 Posts	Re: Rear Coilover Spring Rate Help There are good technical pages on the Chris Alston chassis site. Info on choosing spring rates and setting up coilovers.

05-27-2021, 02:22 PM	#6
Lenny5160 Senior Member Join Date: Nov 2015 Location: Inver Grove Heights, MN Posts: 898 Likes: 604 Liked 432 Times in 225 Posts	Re: Rear Coilover Spring Rate Help Isn't the theory that you want the lightest spring that will hold the car up? That will most easily allow your ladder bar and shock adjustments to do their thing without unnecessary resistance from the springs. __________________ S/ST 51 S/C 53

05-27-2021, 09:18 PM	#7
SGSST109E Member Join Date: Jun 2007 Location: NJ Posts: 349 Likes: 55 Liked 127 Times in 61 Posts	Re: Rear Coilover Spring Rate Help correct

05-27-2021, 10:12 PM	#8
MROD7007 Junior Member Join Date: Jul 2018 Posts: 9 Likes: 1 Liked 1 Time in 1 Post	Re: Rear Coilover Spring Rate Help So your saying as long as the spring doesn’t coil bind and has enough room for compression for bumps that’s the best spring?

05-28-2021, 08:05 PM	#9
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,408 Likes: 508 Liked 739 Times in 284 Posts	Re: Rear Coilover Spring Rate Help What Lenny said ^^^^ Use the shock adjustment/valving for bumps.. __________________ Adger Smith (Former SS) Last edited by Adger Smith; 05-28-2021 at 08:06 PM. Reason: add

05-28-2021, 10:16 PM	#10
CMcAllister Senior Member Join Date: Sep 2006 Location: Fulton County, PA Posts: 564 Likes: 12 Liked 791 Times in 223 Posts	Re: Rear Coilover Spring Rate Help For any situation, there will be 3 or more spring rates which will support the car at the desired ride height with the shock at the the desired center to center (which should be maintained). This will have the different rate springs compressed to different heights. Compressing a spring stores energy which makes the suspension more "lively". Heavy springs compressed a little will react differently than light springs compressed more. Which you use depends on many things in your combination and personal preference. Lighter springs will usually require better shocks to control the housing, especially with ladder bars, certain 4 link settings and/or higher power levels, allowing you to tune it accordingly. Marty's recommendation of 125# on that 14" spring (I assume) and the Santhuffs is likely spot on.