Project GC8: Taking Care Of Business With ST Suspensions – Speedhunters

Project GC8 – my 1999 Subaru Impreza WRX Type RA 555 Limited – is where I want it to be. Even if that means doing them in a non-traditional order.

I’ve been a Speedhunters contributor for nearly a year now, and in addition to hunting down all the raddest cars (and meeting some fantastic people along the way), it’s also exposed me to some of the coolest products, upgrades and tech available on the market. Which is dangerous when you’re embarking on your own project.


One of those is ST Suspensions, whose parent company happens to be KW Automotive. And we’re all familiar with the incredible work KW does when it comes to making cars handle infinitely better, be that for road use or motorsport.

How does ST Suspensions fit into this? Well, ST Suspensions are like an entry-level point into KW. They still boast quality and handling improvements, but at a more affordable price for a wide selection of vehicles. Plus, when you’re ready to delve into the world of high-performance or track solutions, you can easily make the jump to KW.

You might remember from a previous update that I took the Impreza on a five-hour road trip up to Nagano recently, so the idea of a 2-way motorsport-specific kit might be slightly wasted on my daily. One thing did stand out from this trip however: the old Cusco coilovers fitted by a previous owner performed as well as they looked. Terrible.

The rebound adjusters were either seized or spinning freely, meaning there was no way to tell what setting they were on. If I had to guess, I’d say the fronts were set for time attack and the rears to try and mimic a Toyota Century. The whole car felt completely different at each corner.


Thankfully, ST Suspensions had the perfect solution in the form of their XTA coilover kit. This is one of their top-of-the-range solutions which boasts ride height adjustment and rebound as well as camber-adjustable top mounts. But what made this kit particularly special was the customization ST currently offers on all their coilover kits.

Not only could I choose a custom spring colour, but also a neat little message which would be printed on each spring. Have a little scroll down to see what I went for; it seemed fitting given this particular car and the questions I’m usually asked about it.


Yup, that’s cherry blossom pink – the iconic STI colour. And a little text to remind myself that this project is very much being built and not bought.


Why choose ST over KW in this instance? Well, the ST XTA coilover uses the damper technology and components as found in KW coilover kits. They’ve even built in the same factory. But there’s two main differences – the materials being used and the price, with one of those directly affecting the other. KW units use a full stainless steel strut, whereas ST ones use galvanized zinc-coated steel to bring the price down – perfect for a project like this.


With all my parts and tools ready, I set aside a day to remove the old Cuscos and install the new ST XTA units. I have limited experience fitting coilovers, but failure to prepare equals prepare to fail.


Needless to say, as I unbolted the old coilovers something strange happened. All the bolts came loose… with no rounding. No threading, seizing, nothing. Each coilover emerged from its housing with no bloodied fists, and I held each up into the sun like Simba in that scene from The Lion King.

There’s a good reason for this. Firstly, it’s a clean Japanese car. Secondly, it’s never seen a salted road. The engine may be in need of love, but the rest of the car has been looked after meticulously and not subjected to a life of grime, salt or mud. The last Subaru I changed coilovers on was my Forester STI – a Japanese import that’d spent a year in the UK. You guessed it, that process was the polar opposite to this one.


With the old units out, I gave the hubs a quick clean (as well as the top mounting points) ready to offer up the ST XTA units. The fit is perfect; no need to cut or adjust anything even to get the camber-adjustable top mounts in. I nearly fainted, although that might have also been the 30+°C weather.

The only downside was the clearance for the Cusco strut brace, but it’s a small price to pay for otherwise perfect fitment both at the top and into the hub too.


It kept getting better, too. With the ST units firmly in place, I could connect the brake lines and ABS sensor in the provided tabs. No messing, no need for cable ties – just perfect integration with the OEM clips. You’ll have to excuse my surprise here, but that’s what a lifetime of car tuning does to you. A simple, easy fitting process shouldn’t be a surprise, but it’s a welcome change, especially when embarking on the install yourself.

The rears? Exactly the same story. The STI top hats I purchased fit perfectly too, slotting snugly around the damper piston with a satisfying click, the springs firmly held in place with a billet aluminium centering piece. Everything went together as if it were OEM.


To get a basic height, I took measurements off the old units and set the ST XTAs to what I thought would give a similar height. Compared to the heavy, seized spring perch of the Cusco ones, the ST springs move freely meaning ride height can be adjusted in seconds.

As an added bonus, the ST XTA spring perches are made of a friction-optimised polyamide composite material with a stainless steel insert. Sounds jazzy, right? Essentially, that prevents any corrosion occurring between the spring and the strut body. Technology passed down from the halo KW range.


Once I set the front and back heights, I took a step back to see how the car sat. The fronts were a bit low and the rear far too high. No issues however, simply jack it back up, wind the springs down and continue until happy.

It’s difficult to see in the photos, but the rear wheels have positive camber due to the ST XTA lower hub mounting tabs (which are more in line with the OEM shape) versus the old Cusco units which increased camber. It’ll need proper alignment and setting anyway, so this will get resolved later on.


I’ll get on to that once I’ve got the rest of the mechanics and bushings up to scratch. Remember that list I was telling you about earlier on? Yup, it’s a big one. And I’ve just added a wheel alignment to it, but it’ll be absolutely worth it in the end.


Even with my limited tools and experience, it’s been a properly rewarding process fitting my Impreza with this XTA coilover kit. What I anticipated to be a pig of a job turned out to be super easy, and it won’t be long until the fun really begins.

I say that, because on the next episode of Fixing Broken Old Japanese Cars On My Driveway I’ll be pulling out the EJ boxer engine, breaking it open and (attempting) to replace the internals. On my kitchen table.

The anxiety is already kicking in, but until then it’s time to go put some more miles on Project GC8.

Toby Thyer
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