Menu

Shop

Garage

Cart

Account

Products to Compare (max of 3)
X
Compare These Parts

Coilover Spring Rate Chart - Selection and Installation

8/1/2017
Tags: Tech, Hot Rod, Street

Coilover shocks have been around since the late 1950’s and are still going strong on Street Rods and Race cars today. Coilovers offer benefits other springs and shocks may not, including tight packaging for custom suspensions, easy ride height adjustment, and the ability to swap springs at a low cost. There are many factors that go into selecting the correct coilover assembly in order to get a good performing suspension. We will go over some of the basic pieces of information that will help you get the right parts the first time.

Vehicle Weight

The most overlooked factor that we run into is incorrectly estimating the weight of your vehicle. Two of the same make and model cars can vary a great deal depending on how they are configured. You also don’t want to weigh it before the car is completely assembled. Fenders, engine accessories, radiators, etc. it’s all weight and can add up to several hundred pounds in some cases. Do yourself a huge favor and weigh your car. It can save lots of time and frustration down the road!

During the build process, we understand how difficult it can be to get your car on a scale when it isn’t mobile yet. Best case scenario is to have access to a set of scales (such as our part number 475-72593). A much more economical option is to purchase a set of our mock-up coil overs (Speedway part number 916-36037). These are an adjustable, ridged mounted strut that will allow you to build an entire car and transport it to a scale before you buy your shocks! Another great builder’s tip is to buy a piece of roll bar padding (part number 60-415) and put it over the mock up strut. This will simulate the diameter of the spring so that while you are building your suspension you can account for the actual room the finished shock will consume!

Shock angle

The angle that the coilover assembly is installed at has a large effect on what the spring rate will need to be. The greater the angle of the spring, the stiffer it will need to be to support the weight of the car. A coilover with a 10” 225 lb. spring that is installed at 0° straight up and down (90° from the axle centerline) will support 1450 lbs. That same assembly, when installed at a 45° degree angle would need to be a 450 lb. spring to support that weight! A great tool for figuring angles quickly is our part number 910-89409 from Deco.

Installed length

When deciding what installed length you use is another important decision you will need to make. In order for the shock to work to its full potential you should allow at least 2 ½” inches of compression before you hit the bump stops. You want to make sure that you have your ride height established, and then locate mounting points that will allow for sufficient travel in either direction. If you need a 12” mounted length at ride height you should get a shock that is approximately 9” compressed and 14” extended. When selecting the mounting points and ride height of the shock, select the longest shock that you can within reason. The more stroke the shock has, the less risk you will be at for bottoming out or overextending your shocks.

When you give us a call at Speedway Motors to help select your coilovers, have all three of these pieces of information ready to go and we will be sure to help get you the best coilover for your car!

Products Featured in this Article

Related Articles

Everything You Need to Know About Converting Drum Brakes to Disc
by Mark Houlahan - Posted in Tech
7/20/2021
Just about any classic vehicle’s drum brakes can be upgraded to the increased braking performance of a disc brake system. Our Buyer’s Guide provides an overview of disc brake benefits and what you need to succeed with your upgrade.
Selecting The Best Performance Spark Plug Wires
by Jason Lubken - Posted in Tech
7/9/2021
Learn about some of the differences between factory plug wires and the improvements you'll receive with a quality set of aftermarket performance wires in our spark plug wire buyer's guide
Performance Spark Plug Buyer’s Guide
by Mark Houlahan - Posted in Tech
6/28/2021
There is a lot to consider when choosing the proper spark plug for your engine's intended application and power level. Let us take some of the guesswork out with our spark plug buyer's guide.
Solid Axle Choices for Your Traditional Hot Rod
by Eric McMillan - Posted in Tech
6/15/2021
When it comes to a traditional style build on an early hot rod it just has to be rolling on a solid front axle of some sort. In this buyer's guide we take you through I-beam and round tube solid axles, spindle choices, radius rod needs, and more.
How to Use a Stud Extractor Tool
by Steve Lewis - Posted in Tech
6/15/2021
Broken exhaust studs are a common problem. This article describes what you need and how to remove a broken stud from an exhaust manifold. Learn how simple it is to remove broken or stubborn studs with a Titan Tools stud extractor tool.
Steering Shaft and U-Joint Selection Guide
by Speedway Tech Team - Posted in Tech
6/3/2021
Designing a steering system for your street rod or muscle car can be tricky. In this buyer's guide we'll show you how to choose the right steering U-joints, steering shaft, and accessories to complete the job quickly and safely.
Create the Perfect Exhaust Note with Performance Mufflers
by Mark Houlahan - Posted in Tech
6/2/2021
We all want that tough, aggressive exhaust note emanating from our hot rod, muscle car, or classic truck's tailpipes, but which muffler is best suited for your project vehicle? We're here to help with our muffler buyer's guide!
Best Brake Boosters for Better Braking
by Mark Houlahan - Posted in Tech
6/2/2021
Power brake boosters offer lower pedal effort and better braking characteristics, but which one is right for your hot rod, muscle car, or truck? We take the guesswork out of that question with our latest buyer's guide.
Wrapping Exhaust Manifolds to Reduce Under Hood Temps
by Kevin Webel - Posted in Tech
3/8/2021
Learn how to wrap exhaust headers to help keep under hood temperatures down. This articles shows how cast iron exhaust manifolds are wrapped in 1-inch black header wrap with stainless steel exhaust wrap ties.
A Guide to Installing Adjustable LS Motor Mounts
by Jeff Behrens - Posted in Tech
3/4/2021
Follow this step by step guide on how to install adjustable LS motor mounts to set your engine location exactly where you want it.
Error
X
Note
X
Ok