Yoshimura RS-9T Speed Series High Mount Exhaust – 2022-2025 Honda Grom

The 2022-2025 Honda Grom has earned a reputation as one of the most fun and customizable small-bore bikes on the market. Now, Yoshimura is answering the call for a high-mount exhaust option with the RS-9T Speed Series High Mount—engineered for performance, style, and durability.

We've received countless requests for a high-mount system for the latest-generation Honda Grom, and we couldn’t resist delivering. Like our low-mount system, this Speed Series High Mount is precision-tuned for maximum power gains. The stainless-steel header features an 18mm Wide Band O2 sensor bung for optimal tuning, while the RS-9T muffler—fitted with a matte carbon fiber end cap and heat shield—is tucked in tightly to minimize crash damage.

Proven Performance Gains

At Yoshimura, we push the limits of small-bore performance, and the results speak for themselves:

• Up to 10.9% more horsepower at 8,200 RPM
• Up to 7.4% more torque at 6,600 RPM

Our Integrated Sonic Chamber enhances power delivery and gives the Grom a bold exhaust note, all while keeping the Speed Series full system 49-state compliant.

Precision Engineering, Made in the USA

Proudly designed, developed, and manufactured in Chino, California, the RS-9T is built for riders who demand top-tier performance.

Weight & Sound Comparison

Stock System: 7.5 lbs.
Yoshimura RS-9T Full System: 5.9 lbs.

Sound Levels (J2825 standards, with insert):

• 2000 RPM → Stock: 73.6 dB, RS-9T: 79.5 dB
• 5000 RPM → Stock: 82.6 dB, RS-9T: 88.4 dB

Customizable Sound & Performance

The RS-9T muffler is compatible with five different sound inserts, allowing riders to fine-tune power delivery and noise levels:

• SA-15-K
• SA-14-K
• INS-RS9A-K
• INS-RS9B-K