MXA TEAM TESTED: PRO CIRCUIT KX450 TI-6 EXHAUST SYSTEM

WHAT IS IT? The all-new 2024 Kawasaki KX450 will breathe new life into the aftermarket exhaust business because it is in desperate need of some help in the power department. Pro Circuit’s Ti-6 exhaust system is the first pipe that came to mind, not just because Pro Circuit runs Kawasaki’s 250 National and Supercross race programs, but they also supply the exhaust systems used by Kawasaki factory riders Jason Anderson and Adam Cianciarulo. 

WHAT’S IT COST? $1,269.95 (Ti-6), $1,396.95 (Ti-6 Pro).

CONTACT? www.procircuit.com or (951) 738-8050.

WHAT STANDS OUT? Here’s a list of things that stand out with the Pro Circuit Ti-6 exhaust system for the 2024 Kawasaki KX450.

(1) Versatility. The KX450 Ti-6 is designed to pass all Amateur sound standards. For the stricter AMA Pro sound test, Pro Circuit makes the Ti-6 Pro to meet the AMA/FIM sound standards. The 2024 Kawasaki Ti-6 exhaust fits both the KX450 motocross and KX450X cross-country machines. Additionally, it comes equipped with a removable USFS-approved spark arrestor, making it easy for riders to alternate between off-road and closed-course racing. Plus, the head pipe has Pro Circuit’s RC-4 resonance chamber built in to reduce noise and add midrange. The T-6 is made in Pro Circuit’s Corona, California, facility with a titanium head pipe, mid-pipe and muffler canister with a carbon fiber end cap.

(2) Fitment. The 2024 Kawasaki KX450 has a lot of room for improvement with respect to its muffler system. The Pro Circuit Ti-6 titanium exhaust system utilizes all the stock hardware (besides the heat shield, which is unnecessary because the head pipe is tucked in 54mm farther inboard than the 2023 KX450 pipe). The stock muffler has two wire screens in the perf-core and a mechanical baffle, while the end cap is stamped steel. The result is a very choked-up feel and a lack of snap. 

But, that isn’t the major fitment problem. The first issue shows up when trying to remove the exhaust flange nuts. They are tucked behind the frame’s downtubes and hard to access. The best solution is to use a 12mm swivel socket on an extension to get the exhaust flange nuts off. It can also be done, although the process is painstakingly slow with a 12mm open-end wrench. 

In 2019 through 2022, we had issues with the KX450 muffler breaking the subframe bracket, but for 2024, Kawasaki moved the muffler 3 inches forward to lessen the leverage and added a generous rubber-isolated mount to stop the sub-frame from cracking. Still, Kawasaki sent KX450 owners a warning about potential frame cracking where the subframe mounts to the frame.(3) Performance. We had trouble getting the KX450 up on the pipe when shifting from second to third gear with the stock exhaust. The Ti-6 instantly fixed that with vastly improved throttle response and more midrange power, starting from 6000 rpm all the way to the 9700-rpm peak. 

Peak horsepower with the stock pipe (and the rubber plug in the airbox removed) was 57.4, while the Ti-6 pumped out 58.6 horsepower. There is no horsepower difference between the stock pipe and the Pro Circuit Ti-6 from off-idle to 5500 rpm, but the Ti-6 does make anywhere from 2 to 4 horsepower more than stocker from 5500 rpm to the 9700-rpm peak. Top-end power after peak is flat, but the Ti-6 is still 2 horses better than the stock pipe all the way to the 11,500-rpm sign-off. 

(4) Weight. The Pro Circuit Ti-6 titanium system weighs 2 pounds less than the stock pipe.

WHAT’S THE SQUAWK? No complaints. All of the fitment issues are Kawasaki’s fault.

MXA RATING: Unless you like racing around in second gear all the time, the stock exhaust needs to be replaced with the livelier, more responsive, quicker-responding and stronger Pro Circuit Ti-6 exhaust system.