DIAMOND ENGINEERING

Let customers speak for us

from 677 reviews

Incredible, the best!

Without a doubt, the best of the best, it's wonderful, it sounds incredible and the service is excellent.

Javier Villagran

12/05/2025

71207CP Arrow Competition Evo Full Titanium Exhaust for BMW S1000RR 2020-2025 / M1000RR 2020-2024

Will Be Back!

I recently purchased the Arrow Race-Tech Slip-On Exhaust (Aluminum Dark) for my Kawasaki Z900 (’17–’24), and I couldn’t be happier. The quality is top-tier—lightweight, beautifully finished, and it gives the bike the deep, aggressive sound it should’ve had from the factory. Throttle response feels smoother, and the overall riding experience is noticeably more exciting.

Huge shoutout to Bill from Bills Exhaust. His communication was excellent from start to finish—quick replies, honest info, and genuinely great customer service. The exhaust shipped fast with no delays, no issues, and no backorder nonsense. Exactly what you want when ordering parts for your bike.

If you’re on the fence, go for it. The exhaust is incredible, and Bill makes the whole process even better. Highly recommend!

Brian Brayley

12/01/2025

71856AKN Arrow Race-Tech Slip-on Exhaust, Aluminum Dark for Kawasaki Z900 17-24

Arrived super quick

Arrived super quick, no complaints

Anonymous

11/20/2025

IN STOCK M4 Exhaust GP Black Slip on GSXR600/750 2011-2025 SU6112-GP

Great customer support

Great customer support, fast shipping and delivery , and great quality exhaust . Sounds nice 👍🏼 would definitely recommend

Atticus

11/13/2025

IN STOCK M4 Exhaust GP19 Black Slip On 2009 - 2025 2026 ZX6R zx6 KA6922-GP19

Fast service and the pipe is very well made

Fast service and the pipe is very well made.

Anonymous

11/13/2025

72188PD Arrow H.D.1250 Pan America 20-25 Racing St. Steel De-Catalyzed Collector

Purchased the power core 4 along with the mega bomb header

Purchased the power core 4 along with the mega bomb header. Sounds great! Looks even better! Slammed them both on my 22’ KX 250f.

ROBERT T CLARK

11/11/2025

FMF Powercore 4 Muffler KX250F/X 2021-2023 042392 1821-2038

Was trying to find a reseller for Graves products. Stumbled upon this site. No hassles. Ships to Australia (big plus). Now I can mod my dream bike.
Exhaust is gnarly, obnoxious... exactly what I want! Makes all the right sounds.
I'd buy another one if I had another bike.
Super easy fitment, shaved off so much weight with the titanium build.
Absolute piece of art.

Nazzy

11/05/2025

Bill's Exhausts

Great price and amazing sound

Great price and amazing sound.

Michael Adams

10/27/2025

AKRAPOVIC Carbon Fiber Muffler NINJA 400 /500 2018-2025 S-K4SO6-APC 1811-3515

This system with a BT Moto tune sounds and feels amazing

This system with a BT Moto tune sounds and feels amazing. The weight reduction, power increase makes this bike handle even better.
The titanium exhaust system looks amazing.

Lou D

10/19/2025