If you drive a 350Z, you already know the importance of a good exhaust system. Beyond just sound, a well-designed system can improve horsepower, reduce weight, and enhance your Z's personality. Two of the most talked-about cat-back options in the community are the HKS Dual Hi-Power and the GReddy RS-Race. 

But which one is best for your build? Let’s break it down. 

HKS Dual Hi-Power

• Tone: Deep, smooth, and refined. 
• Volume: Aggressive under throttle but relatively tame during idle and cruising. 
• Ideal For: Daily drivers and enthusiasts who want a clean JDM tone without waking the neighbors every morning.  
• Piping Diameter: Dual 60mm pipes to 115mm tips. 
• Materials: Polished stainless steel with excellent weld quality and durability. 
• Performance Gain: Modest but solid gains in the mid-to-high RPMs. 
• Design Notes: True dual exhaust helps with even cylinder scavenging and looks killer from the rear
• Fitment: Excellent. Bolts on without drama. 
• Installation Time: 1.5 to 2 hours with basic tools. 
• Clearance: Good ground clearance despite dual piping.

GReddy RS-Race

• Tone: Loud, raw, and unapologetic. 
• Volume: This system is loud. It has no resonator and is designed to maximize flow, which means it roars at WOT and drones on the highway. 
• Ideal For: Track cars, weekend warriors, or anyone who wants that straight-pipe vibe with more engineering. 
• Fitment: Also solid, but some users report needing slight adjustments to get perfect alignment. 
• Installation Time: Around 1 hour—single exit means fewer pieces to wrangle. 
• Clearance: Better than most, thanks to its tucked design.

If you're building a daily or weekend car and want a deep, refined tone with reliable performance, HKS Dual Hi-Power is a go-to. But if you're chasing track-day thrills and risking blowing sound, or if you run test pipes, the GReddy RS-Race is the better choice.