I went to Perris Raceway and tried Steve’s Pro Circuit Ti-6 muffler system w/ that RED carbon end cap! The updated Pro Circuit Ti-6 Titanium Exhaust System for the 2026 YZ450F is constructed of titanium throughout the head pipe, mid pipe, and canister while the end-cap is carbon fiber. Oh and you can be like Steve and get a red carbon tip or even a blue tip for an extra 175.00 directly from Pro Circuit. Installation of the PC system is painless to install (for Yamaha standards), but always make sure to install the headpipe on the cylinder head studs and then connect the mid pipe. Once the mid pipe is slipped onto the headpipe you can begin to tighten the headpipe nuts. This assures that the mid pipe doesn’t bind and is free.
So how did Steve’s beautiful piece of titanium feel out on the track? The exhaust note on the Pro Circuit Ti-6 is not near as loud or weird sounding as the older Ti-6’s that came on the older models (had a weird flutter to them on higher RPMs). The exhaust note on the 2026 Pro Circuit Ti-6 is deeper and slightly quieter, which I personally like more. The power delivery is slightly smoother down low than stock, but only on throttle opening. At 10% throttle position/opening there is a slightly softer RPM response, which I preferred through corners. Let’s face it, the 2026 YZ450F has plenty of power and managing the delivery more down low isn’t a bad thing for us older riders or guys who want to feel more connection from the rear wheel. If I needed more bottom you can simply run a more aggressive map from the Yamaha Power Tuner App and that can help the “pop” you might be looking for out of corners. I usually run the “Keefer Race Map” with the Pro Circuit system as it makes me happy with the amount of smooth roll on power I have as well as low end excitement. The rear wheel definitely feels connected to my throttle hand and in comparison, the PC system has more bottom end power than that of the Akrapovic that I normally run on my personal Yamaha YZ450F.
The mid-range is where I wanted more power out of the Yamaha and this is where exactly the PC system delivers. The meat of the Ti-6’s power out of corners and accelerating down the next straight is better than stock (most riders should be able to feel this immediately if going back to back from stock to PC). I am able to use second and third gears slightly longer with the PC system (compared to stock) and even though the low RPM response is softer/smoother than the stock system, the mid-range RPM response is more instant. Mid- range RPM response is crisp and makes the Yamaha feel “lighter” when trying to hop over square edge choppy areas of the track when accelerating. Top end pulling power is also slightly better than stock as the PC Ti-6 pulls harder up at the very top of each gear and the PC system does have slightly more over-rev.
I was impressed how the Pro Circuit Ti-6 delivered and spread out its power and made the Yamaha even more fun to ride. If that’s possible? The PC Ti-6 Pro Titanium System runs $1,487.95 and is available over at procircuit.com. Don’t forget about that colorful red carbon tip too!
Steve’s Review: Ok so the best thing about this system is Mitch Payton told me I had the only red tipped Yamaha PC muffler in the world! So, that was cool right? I have the white/red edition bike so it looks amazing. That’s first. Keefer just threw up in his mouth. Secondly, usually aftermarket slip-on’s just move your existing power somewhere different in my experience. So it takes away bottom, gives you some top etc and you usually “feel” something for your dollars. Well, this system really is impressive. I felt like, unlike the FMF and PC slip on’s I have tried on 2025, that this is better everywhere. Not a massive gain in any part of the power but just like a super charged system that gave you more than stock across the board. There wasn’t anywhere that was WAY more power somewhere than stock (to me FMF slip was way more top, PC more bottom) like the slip-on’s I mentioned, it was just better everywhere. I like it a lot! Installation was easy (outside of getting the stock Yamaha mid pipe out of the chassis) and did I mention the red end cap?
