ST Suspensions Coilover Upgrade for WRX

Today our Subaru Impreza WRX gets a suspension upgrade with the ST Suspensions XTA coilover kit along with Whiteline Sway bars for improved handling and ride quality.

ST Suspensions is a division of KW Suspensions that features both KW damper technology and manufacturing for the best coilover kit to improve your handling and ride quality at an affordable price.  They provided their ST XTA Coilover kit – 18245802 compatible with 2002-2007 Subaru Impreza WRX with up to a 5-year warranty.

Whiteline provided their front and rear sway bar kit – BSK007M which includes a 24mm 2 point adjustable front sway bar and a 24mm 3 point adjustable rear sway bar.  This kit comes complete with high-quality sway bar end links and mounting accessories for maximum performance and easy installation.

Our Content Sales Manager, Ian Pak’s 2002 GD Subaru WRX has been suffering from a case of love, it’s been loved nearly to death! Over the years Ian has racked up over 208,000 enthusiastic miles and the car is badly in need of being gone through. We will be going through the car’s systems one by one upgrading them with some serious parts refurbishing the WRX into a solid track competent street car.  The first place we will be attacking is the suspension where we will be replacing the tired shocks with some quality coilovers from ST Suspensions and controlling body roll and dialing out understeer with some Whiteline anti-swaybars.

Many years ago while he was in school, Ian had done some suspension modifications replacing the stock shocks with some Tokico HD OEM replacement parts with Tein lowering springs. He had also installed a Progress 22mm rear sway bar.  The Progress bar is a good match for a stock front bar with mild or stock spring rates but we wanted to apply some of the lessons learned with our awesomely handling  STI Project GD to Ian’s car.

A long time ago this was a reasonable way to get more out of your suspension, nowadays there has been a lot of progress with how a suspension works. Compared to modern stuff, the progressive damping curve on the old Tokico’s is overly stiff and still does not offer the platform control of modern digressive dampers. Lowering springs tend to be too low and too soft, being a looks type of thing rather than a performance enhancement.  Many times, cars with lowering springs simply roll onto the bump stops in hard cornering which greatly reduces grip.  Usually, the front suspension bottoms first and the car will go into relentless grinding understeer.

Well, let’s get rid of this old, worn out 90’s technology and bring Ian’s car up to modern standards!

ST Suspensions XTA coilover’s damping is single adjustable.  The damping adjustment is in 18 steps.  The valving and internals use KW’s valve technology and is similar to a KW Variant II.  The front coilovers spring rate is 6.1 kg, this is considerably stiffer than the stock 2.9kg.  The lowering springs that were on the car were most likely only around 20% stiffer than stock so this is a huge step upward.  Modern damper valving makes the uses of stiffer springs without sacrificing the ride quality very much possible.

The plating of the shock body makes it highly corrosion resistant.  When combined with a stainless steel reinforced engineering plastic spring seat/adjusting collar you have a spring ride height adjuster that will not get stuck to the shock body with corrosion, even after a salty winter.

The rear spring rate is a progressive rate going from 3.9 to 4.1 Kg as the suspension compresses.  This is slightly stiffer than the factory spring rate of 2.9 Kg.