Project GC8: Taking Care Of Business With ST Suspensions

Welcome to another instalment of Fixing Broken Old Japanese Cars On My Driveway.

On today’s episode, we’ll be swapping out a set of old Cusco coilovers for a set of brand-new ST Suspensions XTA items. And because there’s a list of things to do as long as my arm, I’ll be tackling each one individually until 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
Instagram _tobinsta_

The SH Garage on Speedhunters



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Coilovers are always great for stance as well as handling

mortimer gormsby

Bit overkill. Just pull the factory springs out let the car sit on the ground.


Wow, everything went as plan. That's awesome.

And contrary to what you said, the positive camber rear is very noticeable from the pictures but hey, only temporary


I’ve been following your GC articles and I hadn’t heard of ST coil overs previously but knowing they’re effectively KW coil overs I’ll be looking forward to your feed back on these then pulling the trigger on a set for my GC8 too.


Watch this space, and let us know what colour springs you choose!

mortimer gormsby

Working in the drive way - a fantastic story. Can't wait for EJ on the kitchen table.


It’s certainly a challenge!


Make sure to order yourself a set of .026 main bearings to go with a standard set. Order them well in advance too. They are often out of stock for the center thrust cranks and are often needed as the blocks have a tendency of the main bearing housings "growing" as they age.


Enjoying this GC8 story, stoked you got one. I've got a '99 RA WRC Ltd in NZ. but yeah same question - is it an STi? Ha. I was mostly after RA & that blue so happy with mine. Keep it up!


Nice one, how are the mechanics of yours holding up?


2 days later, i just realized the coilover is floating in mid air in the main picture.

what manner of socery is this?!


Really enjoying the articles about your gc8, can’t get enough of anything Subaru!!!!

Just wondering how do the 5 speed box hold up on the gc8???? Is it similar to the gc8 sti 5 speed??? My 6 speed in my liberty is worlds above my 5 speed I had in my bug eye


As far as I know the 6 speeds will handle more power, but then the gearing is different so you loose some of that RA magic. For me, I think the 6MT swap is inevitable as I’m not using it as a rally car, more as a quick road car. Plus the 5MT currently in the car pops 3rd gear…


A great option for a street car GC8 is the RA gear set with 4.11 final drive vs 4.44. I had one in one of my GC8s and it was a beauty.


Is no one going to talk about the fact that the coilovers are floating?


It’s magic


your front camber plates look wrong, either they need to be swapped from L to R side, you want them to slide more to the firewall of the car. you will gain caster which is good and you can - or + the add amount of camber out from the lower oem camber bolt on the knuckle of the shock.

ps: I hope you aren't using that trunk jack to lift the car on the pinch rails which release water, you crush them closed and dent them. the proper spot to lift a subaru is under the front crossmember there is a jack plate to lift the front then you slide your jack stands under the body inner rails closer to the front not on the sides where I mentioned. the rear you jack up on the bottom of the diff to lift both sides up then you add the stands on the plates that hold up diff, you will notice the plates with 2x 12mm bolts and one large 17mm bolt head.

why ? Because you crunch the body work and make rust spots along with not letting water escape the rocker guards, over time you won't have jack up points to pick the car up in a emergency purpose only !


do this work for other cars too?


On my kitchen table.

You WHAT?! Very excited!


Nothing is more satisfying than breaking sweat and equipment for the suspension swap job on the GC8. With the right setup, even ride of decades old car can be improved.

I love to hear more stories of your new love, GC8.


That looks like a fun project. Nice work, love the spring colors!

Some tips - you'd be wise to change the rubber brake hoses and flush/bleed the fluid. An aluminum floor jack would make this work much easier. And torque wrenches are best kept for torquing to spec, not in place of a ratchet/breaker bar.


I’ll add that to the list
Cheers !


When I did this last winter (on a Japanese car that had spent time on UK roads) it was an absolute nightmare requiring fire and hacking! Glad/jealous it went smoothly. Once properly aligned they're incredible things! I went for the full-on KW V3's on mine and they're superb.


It’s amazing what a few years in old Blighty can do to a car. Sounds like you got it all done in the end though!


Love it. ST Coilovers are the best bang for buck out there, great choice! I also have a "NOT AN STI" which was a 1995 WRX. Started as all Subaru parts with exhaust and a tune, which ran 12.9. Then I switched the engine and turbo setup and ran a 10.8. This year its all new again and we are shooting for 9s, with 866whp!

Love seeing these GC8s resurrected and looked after. So many of them are getting to be near beyond repair.


Also, if you are going for an alignment soon, you can swap the pins on the aluminum front control arms so they are flipped the opposite direction. This will give you a little extra castor which really sharpens up the turn in and active camber.