Tcbo1Hamrick
Member
- First Name
- Jonathan
- Joined
- Apr 10, 2026
- Threads
- 3
- Messages
- 6
- Reaction score
- 2
- Location
- Columbus, GA
- Car(s)
- 2026 Nissan Z Heritage
- Thread starter
- #1
I've been drawn to some of the Japanese market parts. These are expensive as hell, but I'm curious about them nonetheless.
Has anyone gotten their hands on the HKS downpipes or the Greddy Power Extreme R Dual exhaust? The HKS downpipes seem interesting. They use a 150 cell catalyst and taper from 75mm to 70mm (3.0 inch to 2.75). That sounds like a very free flowing design that attempts to maintain exhaust velocity without adding back pressure. Being designed and intended for use on Japanese roads I expect they are very civilized when it comes to sound and fumes, but I do wonder if the 150 cell cat is so close to being catless that it leads to fumes, smoking, or are pretty loud?
I can't find much information or a single sound clip of the Greddy. But is a little different than what we're used to on North America. It uses a 70mm diameter which sits right in between the common 2.5 and 3.0 inch exhaust systems we see every day and it has two resonators in the mid-pipe as well as two helmholtz resonators behind the axle with the mufflers. I'm curious if that leads to a truly drone free and quiet cabin under city driving and highway cruising, but a real exotic JDM sound at wide open throttle. Would love to hear if anyone has any experience with either of these.
Has anyone gotten their hands on the HKS downpipes or the Greddy Power Extreme R Dual exhaust? The HKS downpipes seem interesting. They use a 150 cell catalyst and taper from 75mm to 70mm (3.0 inch to 2.75). That sounds like a very free flowing design that attempts to maintain exhaust velocity without adding back pressure. Being designed and intended for use on Japanese roads I expect they are very civilized when it comes to sound and fumes, but I do wonder if the 150 cell cat is so close to being catless that it leads to fumes, smoking, or are pretty loud?
I can't find much information or a single sound clip of the Greddy. But is a little different than what we're used to on North America. It uses a 70mm diameter which sits right in between the common 2.5 and 3.0 inch exhaust systems we see every day and it has two resonators in the mid-pipe as well as two helmholtz resonators behind the axle with the mufflers. I'm curious if that leads to a truly drone free and quiet cabin under city driving and highway cruising, but a real exotic JDM sound at wide open throttle. Would love to hear if anyone has any experience with either of these.
