Tarett 22.2mm RSB installed on 987.2 base Cayman

Just did my first suspension mod, thought I'd go after the low-hanging fruit to address the stock understeer. The car has 35k miles, no PASM or LSD , no other suspension mods, although I maxed the front camber, to about -0.7. I decided to try the Tarett 22.2mm rear sway bar, and keep my OE end links, which were in good shape. I used the softest of the four holes on the Tarett, which gives a lever about 6mm longer than the OE 18.5mm bar. No clearance issues. I got a good drive in after install, we have lots of 2nd-gear corners and switchbacks, pavement from smooth to quite rough, and with some frost heaves. I took it easy initially, but soon found that the car is now very well balanced. I can feel the slip angles on both ends now, and over mid-corner undulations the car holds its line instead of requiring significant corrections. For sure, it's less tolerant of mistakes, you can lift throttle to tighten your line, but you can't stab the brakes. We don't have a lot of rapid transitions here, but I think the tail could get lively. I had to come in relatively hot on the brakes to get any rotation previously, which I don't like to do on the street, now I can be a little mellower with my heel-and-toe 3-2 downshift and trail the brakes. At low speeds on rough pavement, the ride is noticeably a bit harsher. I'm on 18" wheels with all-season Contis. Now, Tarett does not recommend using this rear bar without also using their larger bar, and I don't recommend that you do it, either. Just providing my experience. The next mods I'm eyeing are Cayman R springs and Konis, but I'm pretty satisfied for the time being.

Love my r / koni sport set up. Stock base bars. I did recently snag some tarett front links, though I’ve yet to install. May try to find an s or r bar one day.

Thanks for this post. I bought my 2.9L Cayman a couple of years ago (like yours, original suspension; no mods with maxed out front camber), but didn’t get my first track time until the end of last year at Lime Rock’s FCP Euro Proving Grounds (auto-x) and it was a blast. As I’m having all this fun I noticed the inherent understeer for the first time, which only worsened as my comfort level and pace quickened and the tires and brakes got hot. After that very educational day, I decided that I’d like to do some more track days in 2026 and look into the understeer issue and now understand that it’s a Porsche design decision for various reasons. Before taking the plunge on a suspension overhaul (as recommended by my Indy mechanic due to age/mileage) I have been wondering about trying incremental changes like different tire/wheel combos, sway bars etc. Your post gives me hope that my instincts are on the right track. I looked up the sway bar on Tarett’s website and noticed that the 22.2 bar is for the Cayman R/ Boxster Spyder and there is a 19.1 bar for all other 987s. Both are as you mention designed to compliment a 997 GT3 front bar on the 987. Can you explain why you chose the 22.2 bar over the 19.1?

A bit of a random choice, but I was concerned that the 19 wouldn't be enough. I think 19 on the stiffest setting is the same as 22 on the softest, so I probably would have been happy with that as well. If (when) I do change springs, I may need to be careful that the rears aren't proportionally much stiffer than the fronts, if I want to keep this bar.

Thank you for sharing your experience! I’ma little confused by your conclusion, though? It sounds like you would not suggest others get only this rear sway bar, but you are satisfied with the performance? i went the simpler, cheaper route and just put an “S” tier sway bar on my base model and like the effect there, so I understand what you are going for.

I'm satisfied for my use, and the testing I've done so far. Because it's not what Tarett recommends, and because I have not tested it on wet roads, on track, or for higher-speed cornering, I'm not prepared to say that others should use it. I will say that I've found it to be excellent on dry roads up to at least the top of second gear (60+ mph), very neutral and much better than stock. After another good drive today, the lack of rebound damping with the stock shocks is now what's bothering me most. H&R also has a 987 rear bar that's 22mm, so probably similar to Tarett's, but with two end link holes instead of Tarett's four. Eibach also has a 22mm bar with three holes. Nobody seems to list the lever length in addition to the outer diameter, which could be helpful. They're all probably pretty equivalent, though. I'm glad the S bar (19.1mm, AFAIK) is working well for you, it's probably less harsh than the 22mm options.

Yeah, it’s hard to tell just by diameter (solid, hollow, lever length, etc), but the tarret is likely stiffer. I’ve had the rear step out on me in a corner with a surprisingly greasy section (small muddy section), so I’m ok with the current balance. However, I can see someone more performance/track oriented wanting a different feel. At almost 90k miles, I can also feel rebound damping getting a little overwhelmed on spicier corners if there is some undulation in it.

On another forum, someone posted this info which I didn't personally verify but have bookmarked as a data point. Maybe someone else can corroborate: 117 lb/in - OEM Boxter Cayman : 135 lb/in - OEM Cayman R/Boxter Spyder 122-197 lb/in - Tarett 19.1mm 197-315 lb/in - Tarett 22.2mm