PART NUMBER: 61-2076
Progress MX5 anti-roll bars dramatically improve handling. How? They minimize the traction-robbing body "lean" that rolls part of the outside tires off the pavement. Our Sport-tuned Anti-roll MX5 Miata Sway bars replace skinny OEM Miata Sway bars and rubber bushings with larger diameter (stiffer) alloy steel bars and polyurethane bushings.
More roll stiffness means less body "lean", and the tires stay flatter on the pavement (larger contact patches). The result is more grip and added driver control!
-Less body roll means more traction, faster cornering speeds, and increased driver confidence.
-Polyurethane bushings produce crisp response on turn-in. Progress Anti-roll bars are cold-formed in-house using custom-built precision bending equipment. Laser-cut and CNC bar ends are MIG welded in place using a precise fixture for an exact fit that is more durable than alternatives used by some other choices.
-Size:REAR 16 mm SOLID
-Adjustment Range: Rear 2 holes
-All sway bars are powdercoated metallic gray.
-One year limited warranty.
Brian's APPLICATION NOTES: Lots of testing results in a rather unique rear setup that boxes the factory mount because the factory mount is essentially open, with a lot of flex. Initially we thought of boxing the D clips but once we found the actual source of the flex we tested the boxing and that proved a lot more effective at actually giving us the benefit of the extra bar stiffness compared to stock bar, something most choices overlook. The result is that our rear 16mm is more effective and linear in rate than most bars, even those that are even thicker.
I bought the Progress front + rear sway bar combo for the ND MX5, which included this rear sway bar. I initially installed just the rear bar, on the softer setting, and I drove it for several weeks before finding time to install the front bar. I had not made any other suspension modifications to my car. I wanted to give my impressions of driving with the rear bar only, in case anyone's considering just replacing one sway bar.
I'm ignorant to what someone would want to do for track driving or an autocross event, so I'm not addressing that audience. However, for just street driving, don't replace just the rear bar. The car feels like it wants to fishtail if you go around corners at speeds approaching the speed limit (although the traction control will catch you). The car feels unstable on the highway as the front wheels dig and dive and the rear stays flat and centered. It feels dangerous and unbalanced if you push it even a little. The front takes longer than the rear to settle after coming out of a turn, it feels unpredictable and unsettling. You're definitely better off replacing both bars (or perhaps just the front bar, which I can't comment on).
As for the installation, the rear bar is relatively easy to replace. I tend to work slowly and it took me about 90 minutes including tool setup and cleanup afterwards. I didn't have a problem with the additional braces twisting when I torqued down the subframe nuts, but I had read about the potential issue beforehand, and I used vice grips to hold down the braces before tightening all the fasteners.
Thanks for your review David! We never recommend upgrading just the rear sway bar, that is a recipe for upsetting the balance of the car. There are some race classes that allow only one bar to be upgraded, and in those cases the front bar is the one to do - but in all other situations the front and rear sway bar combo is the right choice as they are designed to work together to reduce body roll while maintaining the right overall handling balance.
-- The Good-Win Racing Team
Installed alongside the Progress FSB. This is my first experience with sway bars, and I have to say: I'm impressed. The car stays almost completely flat in long, fast corners. This instills a lot of confidence.