![Honda Grom Highmount Exhaust [678]](https://motorsportsnewswire.com/wp-content/uploads/2025/02/Honda-Grom-Highmount-Exhaust-678.jpg "Honda Grom Highmount Exhaust [678]")
CHINO, CA – February 8, 2025 – (Motor Sports NewsWire) – One of our favorite small bore bikes, the Honda Grom has a new offering from us here at Yoshimura – our RS-9T Speed Series High Mount!
We’ve had so many requests for a high mount for the latest gen Honda Grom, we just couldn’t resist. This new Speed Series High Mount system, like our low mount, has power optimized to perfection. The header includes an 18mm Wide Band o2 sensor bung to allow for the perfect tune. The RS-9T muffler with matte carbon fiber end cap and heat shield is tucked in tight to the chassis to help minimize crash damage.
When it comes to performance Yoshimura is squeezing every drop from the 124cc small bore Grom engine. Up to 10.9% more HP @8200 rpm and up to 7.4% torque @6600 rpm. Our Integrated Sonic Chamber allows us to boosts power over the stock unit and gives the Grom a little extra bark all while keeping the new Speed Series full system 49 state friendly.
Yoshimura’s RS-9T is proudly designed, developed and manufactured in Chino, California.
![Our RS-9T header with Integrated Sonic Chamber and 18mm Wide Band o2 sensor bung [1]](https://motorsportsnewswire.com/wp-content/uploads/2025/02/Our-RS-9T-header-with-Integrated-Sonic-Chamber-and-18mm-Wide-Band-o2-sensor-bung-1.jpg)
![Our RS-9T header with Integrated Sonic Chamber and 18mm Wide Band o2 sensor bung [2]](https://motorsportsnewswire.com/wp-content/uploads/2025/02/Our-RS-9T-header-with-Integrated-Sonic-Chamber-and-18mm-Wide-Band-o2-sensor-bung-2.jpg)
![Our RS-9T header with Integrated Sonic Chamber and 18mm Wide Band o2 sensor bung [3]](https://motorsportsnewswire.com/wp-content/uploads/2025/02/Our-RS-9T-header-with-Integrated-Sonic-Chamber-and-18mm-Wide-Band-o2-sensor-bung-3.jpg)
![Our RS-9T header with Integrated Sonic Chamber and 18mm Wide Band o2 sensor bung [4]](https://motorsportsnewswire.com/wp-content/uploads/2025/02/Our-RS-9T-header-with-Integrated-Sonic-Chamber-and-18mm-Wide-Band-o2-sensor-bung-4.jpg)
Our RS-9T header with Integrated Sonic Chamber and 18mm Wide Band o2 sensor bung
Power gains with our RS-9T for the Honda Grom were big time for this small bore!
2022-25 Honda Grom RS-9T High Mount full system pricing and Info
2022-25 Honda Grom RS-9T Speed Series FS SS/SS/CF WF
Part #12122SR520
MSRP: $699.00
Hi-res images available here: https://www.dropbox.com/scl/fo/i73iszf8f7m9hi8opfv3e/ALlTPmEVYYHfW0JcToIFYNg?rlkey=hp6ntbkknno63muw6hizdc1tc&st=c9v0vk73&dl=0
Weights:
Stock system: 7.5 lbs.
Yoshimura RS-9T full system: 5.9 lbs.
Sound levels:
(Using 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
About Yoshimura
Yoshimura is renowned for its Research and Development. But producing the finest exhaust systems in the world requires more than a big R&D department. Yoshimura is the leading manufacturer of exhaust systems because our commitment to R&D is matched by our dedication to uncompromising quality standards and our expertise in manufacturing pipes that meet those standards.
Source: Yoshimura Research and Development of America
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