Understanding Lowering Springs
 

Understanding Lowering Springs

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Lowering springs are the most common suspension upgrade made by Camaro owners. They are a simple and relatively inexpensive way to modestly improve suspension performance and dramatically improve the looks of your car. However, there is not much solid technical information out there. The decision often gets made based strictly on ride height or what more people recommend in a particular thread. In this post I am going to provide enough information to help you make a more informed decision but, hopefully, without overloading you with so much that it makes the decision harder. Fortunately, this is a pretty straightforward affair for 5th Generation Camaro owners as it doesn't require much in the way of supporting modifications.


To Lower Or Not To Lower

The allure of lowering springs is obviously to improve performance and aesthetics as stated above. On the performance side of the equation a good set of lowering springs can improve steering response, cornering stability, body roll, traction, and even has aerodynamic advantages. I don't think I need to explain why performance cars look better lowered. They just do. It is the way the car gods intended for them to be, plain and simple.

But like all modifications there are tradeoffs that have to be made. A lower ride height means less clearance. You have to be aware of that and possibly change where and how you drive/park in some situations. Steep driveway and parking lot entrances can sometimes be a problem and you will quickly realize that you fiercely hate speed bumps. Depending on just how low you decide to go you may find that you cannot pull as far forward in parking spots because your front no longer clears the curb. Oh, and be careful about swinging that door open when parked on the street because it may not clear the curb either. The other tradeoff is that the way the car rides will change. Period. Don't let that scare you, it does not mean that the car has to ride poorly but it will be different.


Spring Rate

Spring rate refers to the amount of weight it takes to compress the spring a certain distance. The higher the rate the stiffer it is. The lower the rate the softer it is. To achieve the improvements in performance and to compensate for the reduction in ride height, lowering springs will always have a higher spring rate than stock springs. As I mentioned previously that does not mean the car has to ride poorly. Manufacturers can tune the spring rate and performance characteristics on a lowering spring in a few ways; the diameter of the wire used (thicker is stiffer, thinner is softer), the diameter of the spring's coils (the greater the diameter the softer it becomes), and the number of coils in the spring (the more coils there are the softer the spring gets). Higher spring rates also reduce body roll keeping the car flatter in the corners.


Linear and Progressive Springs

The two categories of springs commonly used in automotive applications are called linear rate springs and progressive rate springs.

Linear rate springs, also known as standard or specific rate springs, are the simplest spring design there is and are relatively inexpensive to manufacture. The spring has a very uniform design from top to bottom with the coils evenly spaced and all the same diameter. The spring is one rate from top to bottom. This has some advantages for performance at the cost of reduced ride quality. You will most often see a linear spring used on coilovers but some stand alone lowering springs do use this design or some variation of it.

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On progressive rate springs the size and spacing of the coils varies. Parts of the spring will have tighter coils that are close together and others with have larger coils that are spaced out more. This creates different spring rates in different parts on the spring. The first section is relatively soft to absorb bumps and cracks in the road for a smoother ride but as the spring compresses the rate increases and it becomes more firm. Because it offers the best of both worlds progressive rate springs tend to be the most common type of lowering spring. They do cost more to make so you will pay more to buy them.

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Dampers

The other piece of the equation is your dampers, more commonly referred to as shocks and struts. They tame the movement of the springs as you go down the road so that you don't bob and bounce all over the place. It is important that your springs are designed to play well with your dampers otherwise their service life and your ride quality will suffer. This is especially true on the ZL1 which is equipped with a marvel of modern engineering, Magnetic Ride Control, rather than traditional shocks and struts. The quickest way to trash them is to try to go too low. 1-1.5" is a safe drop on the stock parts and is well within the range of alignment adjustments available.

Excellent Post Chase! Couldn't have said it better myself!!! :happy0180:

Great post.

Chase, can you contrast or put this in context with Coilovers. I know not all coilovers are used for lowering, but I know many come with adjustable ride hight, so just curious about the differences.

Thanks guys!

Absolutely. Coil overs are a very different animal so I am working on another thread specific to them.

What about us guys that use the car as a DD and track it on weekends. I'd like some spring rates like BMR/Apex but w/o a 1"+ drop, maybe .5". I don't want a slammed low rider, I know Chevy put a lot of effort into getting the 1LE/geometry to handle with the package as designed, I just want to get rid of the some of the lean while at the track.

For what you are describing a good set of coil overs is probably best. They will allow you to fine tune the ride height and dampening for street or track use. I am getting ready to install a set of RideTech coil overs on my car and that is what I would recommend for you as well. You might also want to consider a sway bar upgrade to help control body roll.

Very informative, thanks Chase! This will come in handy when I'm looking to do some upgrades.

Glad to hear that. Do not hesitate to hit me up if you have any questions.

Pedders front springs actually have a lower front spring rate than the stock SS and SS/1LE.

Front coil 220032, Linear Rate, 130Lb/inch or 2.3Kg/mm
Rear Coil 220033, Linear Rate, 433Lb/inch or 7.8Kg/mm

Matt

"Always" is an absolute term which is, of course, dangerous to use. However, the Pedders springs are not true linear rate springs. I believe they are actually a dual or multi-rate spring (kind of a hybrid spring) which means there is a lot more going on there and the rates quoted do not tell the entire story. If you assume that they were a true linear rate spring and those rates are correct then they would be about 80lbs/inch softer in the front than the next closest set of Camaro springs and those springs would have close to a .5" less drop. That would lead to a lot of nose diving when braking and bottoming out.

Pedders claims they are a "linear rate" and I received that text from an email I sent to Pedders AU after Pedders USA closed shop. It was very interesting to me as before I got them Pedders USA stated the spring rates were higher than the stock springs rates, but would not provide the rates. My car sits 14/15mm lower in the front and 30/35mm lower in the rear with the Pedders set-up.

What is the difference between a linear rate spring and a dual or multi rate spring? Assuming all Gen5 drops springs that are installed on a stock strut (not coilovers) have to be one or the other.

Thanks,
Matt

Great read lots of great information.

Thanks for the info Chase! I was just coming on here today to order springs for my 1LE. Perfect timing!