I am seeking some expertise on suspension to explain to me some stuff.

I'm thinking of going with the Tein S-tech lowering springs using the stock shocks. Lots of people are saying using lowering springs without changing the stock shocks will kill the shock faster. The either recommend aftermarket shocks or coilover kits.

To my understanding, the reason the S-tech + stock shock combo will kill the shocks is because the S-tech's stiffness is higher than the stock spring, and that stiffness is not matched to the shock. Correct me if I'm wrong here...

If this is the case, how will getting aftermarket shocks like the Tokico D-spec or Koni-yellows be any better? Aren't those shocks also designed for a particular spring rate?

i.e. Take the S-tech + Tokico combo. The Tokico's have adjustable dampening, but not adjustable ride height, so the height is determined by the S-tech. If you choose a dampening level that is either too low or too high, then wouldn't that be the same effect as you using the S-tech + stock shocks?

Coilovers that have adjustable height only such as the Tein Basic, vary the height by changing the compression of the spring on the threaded support on the bottom. If I change the height to maximum low, then the spring would be stiffest already, and if I change the height to maximum height, then the spring would be softest. In either case, the shock is not adjustable, so the shock somehow has to compensate for all the possible stiffness adjustments the spring can be set and still be "okay"? Because at some point, wouldn't it run into the situation of having the spring too stiff mismatched to stock shocks and killing them?


Please someone educate me, as this has been confusing for me.

 

Lowering springs lower the car by shortening the springs.....

This is usually coupled with stiffer springs to make up for the loss in suspension travel and better handling. Stock shocks are valved to dampen stock spring rate springs...increasing the spring rate too much will make the spring rate/damping mismatched...and results in stock shocks being overpowered by the springs.....causing faster wear, and early failure...as well as poorer handling.

Aftermarket shocks like the Koni's are adjustable damping..and are designed to be used with aftermarket springs...so they stand up better to the increased springrate

Tein ( and coilovers)adjust the ride height by adjusting the shock body below the springs...so it doesn't effect the springrate..or pre-load...and doesn't change the designed travel of the suspension

 

Dannobre, you keep referring to "stock springs".. i.e. "stock springs being overpowered by the springs".. do you mean "stock shocks"?

Also, the threaded shock body for adjusting height.. you meanto say they odn't change the height by moving the bottom piece that holds the spring in place? but instead another piece that "extends or lengthens" the shock tubE?

 

Sorry...bad day at work..I'll go back and edit


The height adjustment of coilovers is independent of the spring length.....so yes...your description is valid

 

So in all, you too do not recommend the Tein S-tech with stock shocks?

 

As long as you know that your stock shocks will not last too long...and will be under damped then it really isn't that big a deal if you are just looking for the drop without any performance gains.

If you are looking for performance upgrades this is not the way to go

 

I wouldn't recommend the OEM shocks with lowering springs. The OEM shocks are underdamped as it is, and they'll be that much more underdamped with a stiffer spring.

I'd wait and pair the springs with a set of Koni yellows or Tokico D-Specs and just do it once, especially if you're paying someone else to do the install. The Koni is a better shock, but Tokico does have an option that allows you to adjust the rears on the car, which is nice (the rear Konis must be removed from the car for adjustment).