Here's a list of lowering spring rates that have been found over the net. I recently found out the rates of the Stock MKIII Pre-89s and the Whiteline Springs, so I've added them here along with the other list. I'll try to find out the spring rates from various companies in the future. I got the Whiteline Spring Rates from an email from a Whiteline Customer Service person, so it's reputable. And as for the Stock MKIII Pre-89s, they seem plausible as a site said they are 16% softer than the Stock MKIII 89+. Before anyone says Tanabes are linear, they are not. While I have no personal experience with them, I emailed Tanabe and a rep said they are progressive in some areas, and linear in others. This means its progressive since its not one set spring rate, as far as I can tell.
There are some debate about the stock MK3 springs. Some manufacturers who give out rates say the rates are 15-30% more than stock which would actually lead the 89+ springs to be around 390 lb/in in the front and the 87 springs to be around 330 lb/in in the front. But most really wouldn't care about the stock spring rates because it's still 4x4 height and stuff.
* Stock MKIII Pre-89
* Front: 461 lb/in
* Rear: 180 lb/in
* Drop: It's higher than the Stock MKIII 89+
* Type: Linear
* Stock MKIII 89+
* Front: 461 lb/in
* Rear: 215 lb/in
* Drop: 0
* Type: Linear
* Stock MKIV
* Front: 430 lb/in
* Rear: 219 lb/in
* Drop: 0
* Type: Linear
* Notes: Only the front MKIV Springs will fit our cars.
* Eibach
* Front: 343-628 lb/in
* Rear: 126-257 lb/in
* Drop: 1.3" - 1.0"
* Type: Progressive
* Suspension Techniques
* Front: 442 lb/in
* Rear: 147-175 lb/in
* Drop: 1.3"
* Type: Linear Front, Progressive Rear
* H&R
* Front: 575 lb/in max
* Rear: 285 lb/in
* Drop: 2"
* Type: Progressive
* Tanabe
* Front: 442 lb/in
* Rear: 207 lb/in
* Drop: 1.1" - 0.6"
* Type: Progressive
* R*SR Race
* Front: 677 lb/in
* Rear: 335 lb/in
* Drop: 1.4" - 0.8"
* Type: Linear
* R*SR Sport
* Front: 503 lb/in
* Rear: 262 lb/in
* Drop: 1.2" - 0.8"
* Type: Linear
* Tokico
* Front: 395 lb/in
* Rear: 198 lb/in
* Drop: 1"
* Type: Linear
* Whiteline
* Front: 381 lb/in
* Rear: 218 lb/in
* Drop: 1.0
* Type: Linear
* Intrax
* Front: 700 lb/in max
* Rear: 220 lb/in
* Drop: 1.6" - 1.3"
* Type: Progressive
* B+G Suspension
* Front: ?? lb/in
* Rear: ?? lb/in
* Drop: 1.3"
* Type: Progressive
* Notes: Said to have similar spring rates to Eibachs.
* Apexi
* Front: 626 lb/in
* Rear: 240 lb/in
* Drop: 1.3"
* Type: Progressive
* Aerospeed
* Front: ?? lb/in
* Rear: ?? lb/in
* Drop: ?
* Type: ?
There are some debate about the stock MK3 springs. Some manufacturers who give out rates say the rates are 15-30% more than stock which would actually lead the 89+ springs to be around 390 lb/in in the front and the 87 springs to be around 330 lb/in in the front. But most really wouldn't care about the stock spring rates because it's still 4x4 height and stuff.
* Stock MKIII Pre-89
* Front: 461 lb/in
* Rear: 180 lb/in
* Drop: It's higher than the Stock MKIII 89+
* Type: Linear
* Stock MKIII 89+
* Front: 461 lb/in
* Rear: 215 lb/in
* Drop: 0
* Type: Linear
* Stock MKIV
* Front: 430 lb/in
* Rear: 219 lb/in
* Drop: 0
* Type: Linear
* Notes: Only the front MKIV Springs will fit our cars.
* Eibach
* Front: 343-628 lb/in
* Rear: 126-257 lb/in
* Drop: 1.3" - 1.0"
* Type: Progressive
* Suspension Techniques
* Front: 442 lb/in
* Rear: 147-175 lb/in
* Drop: 1.3"
* Type: Linear Front, Progressive Rear
* H&R
* Front: 575 lb/in max
* Rear: 285 lb/in
* Drop: 2"
* Type: Progressive
* Tanabe
* Front: 442 lb/in
* Rear: 207 lb/in
* Drop: 1.1" - 0.6"
* Type: Progressive
* R*SR Race
* Front: 677 lb/in
* Rear: 335 lb/in
* Drop: 1.4" - 0.8"
* Type: Linear
* R*SR Sport
* Front: 503 lb/in
* Rear: 262 lb/in
* Drop: 1.2" - 0.8"
* Type: Linear
* Tokico
* Front: 395 lb/in
* Rear: 198 lb/in
* Drop: 1"
* Type: Linear
* Whiteline
* Front: 381 lb/in
* Rear: 218 lb/in
* Drop: 1.0
* Type: Linear
* Intrax
* Front: 700 lb/in max
* Rear: 220 lb/in
* Drop: 1.6" - 1.3"
* Type: Progressive
* B+G Suspension
* Front: ?? lb/in
* Rear: ?? lb/in
* Drop: 1.3"
* Type: Progressive
* Notes: Said to have similar spring rates to Eibachs.
* Apexi
* Front: 626 lb/in
* Rear: 240 lb/in
* Drop: 1.3"
* Type: Progressive
* Aerospeed
* Front: ?? lb/in
* Rear: ?? lb/in
* Drop: ?
* Type: ?