Q: How do I install an adjustable coilover kit?
A: There are 2 ways for this step, either bolt on or weld on.
The process is very simple. There are 2 ways to install them. Before
you install coilover springs, you need to make sure you have stronger
aftermarket struts installed. For more information about how to install
insert struts in your rear, see the Suspension FAQ.
Method 1: If you would like to keep your original spring perch location, you can simply unscrew the top screw of your insert strut and slide the collar on. This would require a very short collar, or you will not be able
to screw the top screw back on top. If you have collars that are too
long then they will need to be trimmed. Pictured below is a Ground
Control kit that comes with very short collars. Your range of height
adjustment will be very small. The good news is that if you are using
the original spring perch, it won't drop your car down too much anyway.
Finally you must secure the collar so that it is not loose based on the
instructions of the manufacturer.
Method 2: The proper way to do the installation is to have the original
spring perch machined off, and having the new collars welded on. This
will also keep you away from possible rattles from loose suspension parts.
It would be ideal in this situation to get longer collars so that your range
of adjustment will be greater. Of course you can't go down too far with-
out having to remove the original brake line tabs.
After either method 1 or 2 is performed, it's a matter of putting the
top spring holder (hat) on top, and bolting on your original strut top.
Some hats have a hole that is too small for the strut rod to go through.
In this case you will have to drill or machine it out to size. Also pictured
below is a finished product using the weld on method. (MR2 pictured)
Spring Rates and Drop Height
We offer the spring rates for comparison between brands, also as helpful information when choosing custom spring rates. Spring rate figures are in lb/in domestic figures, to convert to kg/mm international, divide figure by 56. If there are 2 values listed, that means that the spring starts at one rate, and ends at another rate under full load. There are some conflicting figures for stock, based on source, and location, so if you have any missing or correct information please email.
ST165 | |||
Brand | Front | Rear | Drop (In) |
Stock1 | 140-168 | 112 | 0 |
Stock2 | 123 | 106 | 0 |
Stock JDM | 134 | 140 | 0 |
TRD | 224 | 202 | 0 |
PI (UK) | 224 | 112 | 1.5 |
ST185 | ||||
Brand | Front | Rear | Type | Drop (In) |
Stock (< 10/91) | 174 | 162 | Progressive | 0 |
Stock (> 10/91) | 123 | 168 | Progressive | 0 |
TRD (Street) | 224 | 218 | Progressive | 0 |
TRD (Lowering) | 224 | 218 | Progressive | 0.79 |
TRD (Rally/Dirt) | 240 | 184 | Linear | 0 |
SARD | 174-252 | 118-252 | Progressive | 1.4 |
TEIN H | 235 | 162 | 1/1.2 | |
INTRAX | Progressive | 1.5 | ||
A'PEXi | 300 | 212 | 1 | |
Whiteline | 175 | 135 | Linear | 1.5 |
Good Coilover Rate (Street) | 550 | 350 | Linear | 1-3 |
Good Coilover Rate (Race) | 750 | 500 | Linear | 1-3 |
ST205
TEIN H 1.4-5.8 1.2-5.3