ST XTA coilovers (rebound adjustable, with camber top mounts front)

[Tor]

I think the XTA coilovers are not getting the attention they deserve

They are nothing like the ST X which corresponds to KW V1 and the dampers for both are made by a 3rd party.

XTA dampers are made by KW themselves and are rebound adjustable and even comes with camber adjustable top mounts for the front. As such they are more comparable with V3 in my opinion.

I personally think this is why they are not marketed as many might decide on these instead of V3. From a sales perspective I don't think that is very clever, as I think KW/ST lose customers, who look at lower priced products, to other brands instead.

So hence this thread. Starting out with a small unboxing video:

[ame="https://www.youtube.com/watch?v=c6rrCagn5gI"]ST XTA coilovers for the GT86/FR-S/BRZ - unboxing[/ame]


Though lacking in compression adjustability, in one aspect I think they are even more interesting than the V3. The front spring is 6 kg/mm as opposed to the 4 kg/mm on V3. The rear is 5 kg/mm on both. Even if the 6/5 ratio relatively makes the rear bit soft, I think this can be plenty compensated with geometry or swaybars. I am interested hearing opinion on that... Otherwise it remains to be seen.

So in a weird way, I think these "V2" coilover not only fit below V3, but in some aspects could be called a V3.5 above the V3, halfway towards the Clubsport (with the Clubsport front spring rate and camber adjustable front top mounts).

Unfortunately, I just started a new job and have to go away for a few weeks, so it will be some time before I get a chance to install them.



Plenty of camber should be achievable:


.

[yip]

Just installed mine and had the car corner balanced this week!

I'm not at a skill level to really have an opinion as to how good they are or put into words the handling capabilities of these over the stock setup.

What I can say though is that the car went from very rough. easily unsettled and very jolted over large cracks or pot holes to smooth and much more comfortable. Mid corner bumps no longer cause the car to lose traction and I now have much more confidence.

The only drawback that I have found is that over choppy concrete highways you get a constant knock when driving over the control joints and I am assuming this is due to not having the rubber strut mount anymore.

I made the decision to buy these based on the recommendation by my alignment shop to buy KW's. The XTA's were just under my budget of $2k and so far I don't regret my purchase.

I'll have to report back here after I go to the next track day at Buttonwillow.

[Tor]

Sounds good. Looking forwards to having time to get them installed. I am still missing parts though (e.g. LCAs) and I still don't have the time anyway due to work commitments.

Just installed mine and had the car corner balanced this week!

How much did you lower it?

[icybrzzz]

Thank you for posting this, was interested in these coilovers for my BRZ but I could not find anything on them.

Please let me know how they perform once installed. Other options I was looking at were:

KW V3 + Raceseng Cascam camber plates
RCE T2 + Raceseng Cascam camber plates
KW Clubsports

Considering the price difference, the ST XTA seem like a good value for the money if they perform anywhere near the v3/t2 coilovers. I know that's probably not the case but seeing as there is not much information available on them, you can't count them out yet.

[Tor]

I didn't drive the V3 or Clubsports, so it will be difficult for me to compare. To make a real proper comparison on how they perform vs. V3 or Clubsport, someone else who has one of the above needs to drive my car on a track. Timeframe for that to happen would earliest be april or may. Even doing so, it will probably be difficult to tell if any differences they may feel is due to other differences in setup. Or maybe they won't push a loaner as much as their own.

A lot of people already said they ride comfortably. Combined with the relatively high spring rates, it suggests to me that the damper must be at least of somewhat decent quality. This assumption is actually what made me buy them.

If the springs are the same, and the damper works to keep the springs in control, I can't see why they wouldn't perform the same - except for 2 things:

- The lack of compression adjustability for fine tuning. I assume the XTAs are preset at some intermediate setting. (In that respect it would be interesting to know how much the average track-day racer fiddles with stuff like that - personally I imagine I would rather spend the expensive track time driving that adjusting suspension).

- The 6/5 front/rear spring rate, but I think I can work around that with camber and/or stiffer swaybar in the rear. Perhaps it will still make a noticeable difference to those driving the Clubsport, which will remain to be seen.

[yip]

Originally Posted by Tor

Sounds good. Looking forwards to having time to get them installed. I am still missing parts though (e.g. LCAs) and I still don't have the time anyway due to work commitments.



How much did you lower it?

About 1 1/2" front & back:

[Tor]

Nice car, I like the blue ones! I aim for 3 cm (≈1 1/4 inch).

Looks like you have camber adjustable LCAs too. What are your camber settings?

[yip]

Originally Posted by Tor

Nice car, I like the blue ones! I aim for 3 cm (≈1 1/4 inch).

Looks like you have camber adjustable LCAs too. What are your camber settings?

SPL LCA's were installed at the same time as the coilovers.

I don't know what the settings are. The alignment shop asked me on a scale of 1-10 with 10 being a max track setting and I said 7-8.

They did supply me with the corner balance weights. We didn't adjust the damper settings and just left them the way they came from ST.

The alignment shop stated that adjusting the damper will adjust rebound and compression at the same time.

Like I stated earlier I consider myself novice as I have no real track experience or instruction but I get the feeling that the car is much more neutral now.

Even at the height I am at the car rides much better than stock as far as comfort goes. It's not typical that you can lower a car this much and actually have a smoother more comfortable ride.

I'm looking forward to the getting some instruction on the track as my friend is a race instructor and is actually the guy I ordered the coilovers & LCA's through. He has an employee at his company that has almost the exact same setup on his FR-S (also Ultramarine blue) as me and he says the setup is more than adequate for someone not looking to break lap records. He has given his employee in car driving instruction on a streets of willow and button willow so I feel very fortunate to get advice from someone that has experience with the same car and setup on track.

[Tor]

Thanks for the details. I think we made a good decision.

[cdrazic93]

I would like to know if @Racecomp Engineering has tested/reviewed these?

[Tor]

@cdrazic93 , I've searched wide and far for any info on these coilovers, and found absolutely nothing, besides from a few users in various forums reporting that they ride well, like Yip above. So I highly doubt anyone tested them in a performance context.

I found yesterday that KW posted a video showing the assembly of ST XA (XTA just means the top mounts are included) coilover about a month ago. I bet those are the same machines being used to make V3/Clubsport and probably the same people doing the work. It supports my theory: looking at how mine compares to V3, I would venture to say that they are probably largely grabbing to the same parts too.

[ame="http://www.youtube.com/watch?v=q2EuIjSKH1E"]http://www.youtube.com/watch?v=q2EuIjSKH1E[/ame]

[swarb]

One complaint I have seen from the lower model st is that they don't go low enough.

Likes: Nice looking top hat, looks strong and wont slip. Coarse threaded collars. Slotted front upper hole for extra camber adjustment.

Dislikes: Start nut for camber adjustment(tool included?). Might not go low enough for those looking for a low drop.

Opinion/not sure if lowering too much may reduce bump travel, but helper springs allows it to have plenty of droop travel. Maybe someone can confirm if my theory is correct.

[Tor]

One complaint I have seen from the lower model st is that they don't go low enough.

The XTA is very different from the ST X. As far as I read elsewhere, the X damper (and KW V1) is made by AL-KO. Personally, I wouldn't replace my good stock suspension with either or any other brand in that price range.

The XTAs are made and assembled by KW, as can be seen in the video above.

Dislikes: Start nut for camber adjustment(tool included?). Might not go low enough for those looking for a low drop.

You mean the 4 bolts that hold the camber plates? Those a Torx TX40 or 45, you probably have those in your toolbox already. It's exactly the same on KW Clubsport. Besides from the wrench I showed in the video in the first post, there are no tools included. There is no fancy purple knob to set the rebound either, just use a 2 mm hex bit or Allen key - that is what's at the end of the KW purple knob too.

Opinion/not sure if lowering too much may reduce bump travel, but helper springs allows it to have plenty of droop travel. Maybe someone can confirm if my theory is correct.

The helper springs are exactly the same as on Clubsport/V3. So if it won't be different than on either of those.

Also the cylinder bodies designs are identical between the Clubsport, V3 and XTA (material is the only difference). The approved drop is the same for all 3 models: 320 mm from hub center to fender. Anyone looking for extreme drops, probably wouldn't look to KW in the first place, or hence be interested in the XTAs either.

[Racecomp Engineering]

I have not had first hand experience with them. A couple thoughts...

You can get a lot of camber on a ST/KW/RCE coilover without camber plates.

I don't have any reason to think these wouldn't be decent coilovers. A lot will depend on how they set the compression curve. Part of me thinks that would be a more worthwhile adjustment than rebound as long as you're sticking with the standard spring rates, but I'm just thinking out loud. Overall, they're probably a pretty good street and light track coilover and I'd think about getting them without camber plates. Maybe add your own.

- Andrew