Regular Rear Springs vs Variable Rate.


Jul 24, 2010
My '87 GN is getting a little saggy in the back. I don't want the back jacked-up,but would like to bring it back to stock height or a touch higher.

Looking at the nos4gn site,they have the regular rear springs,and the variable rate springs. What are pro's and con's between the 2?

Note: One thing that is important to me is NOT to give this car a harsher ride. The roads up here in Upstate NY are horrible. The less slamming/pounding the better!


Steve. '87 GN,t-tops. PowerLogger,60#,t-t alky chip,Accufab reg.
rear springs

I did the variable rate/cargo springs from Kirbin years ago and never looked back. Did for me just what you guy's are looking for. HTH.
shifty 6, do know how much lift one can expect from installing the variable rate spring in the rear as apposed to the stock saggy springs?
A variable spring will get harder as weight (bumps, dips, passengers) is increased. It will also load and unload under accelleration which induces wheel hop. If all you're planning on doing is cruising around and no hot rodding then you should be fine but if you take it to the track you'll have issues getting traction off the line.
My old GN had air shocks that I could pump up to raise the car/carrying capacity. Worked well.
I would think most others would go up in smoke with a launch like that. Still looks like a rough ride with that huge unload in there. Bad ass video anyway! thank you for sharing!
Few pointers....we have used the same supplier of our springs for over dozen plus years or longer never an issue...

I can tell you this even on regular cars or SUVs any time you change the springs or struts....they wil lsit slightly higher at least a few days or so til they settle in.

Also your springs assuming they are original makes them 25 plus years old so they are sitting low happens gradually which is why you may not realize it.

Variable rate means they sit normal basically and when you add weight they don't sag...your car when you put 2-3 people in the back seat or 200lbs in the trunk probably squats down in the back...Variable rate sprinsg stops that from happening. variable rate don;t sit higher than stock they come into play when you ad weight.

That is how I always understood how they worked...if you had a 86 GN they sat lwoer in the frotn GM changed the spring setting on the 87 models....

we have many of the items related to suspension that would vastly improve the ride quality of your car....shocks being another area to address.