Exhaust Upgrades
Thread Starter
Cruising
Joined: Apr 2026
Posts: 13
Likes: 1
From: Chicagoland
Exhaust Upgrades
Hey everyone,
I’m looking for some advice on a planned exhaust upgrade for my 2015 C7 Z51, M7, factory NPP. The car already has the AFM valves bypassed/deleted, and I’m keeping NPP functional.
I picked up a complete OEM C7 Z06 exhaust system with about 7k miles, including:
A few questions for anyone who has done this or measured the parts:
Any real-world feedback, measurements, or photos would be appreciated.
I’m looking for some advice on a planned exhaust upgrade for my 2015 C7 Z51, M7, factory NPP. The car already has the AFM valves bypassed/deleted, and I’m keeping NPP functional.
I picked up a complete OEM C7 Z06 exhaust system with about 7k miles, including:
- Z06 exhaust manifolds
- Z06 primary cats/downpipes
- Factory center/X-pipe section
- AFM/NPP hardware
- Z06 NPP mufflers
- Install the Z06 manifolds and primary cats/downpipes
- Use either an EOS or Speed Engineering X-pipe
- Do a secondary cat delete
- Install the lower-mile Z06 NPP mufflers
A few questions for anyone who has done this or measured the parts:
- Are the Z06 manifolds and primary cat/downpipes a worthwhile no-tune upgrade on an LT1/Z51?
- Is the Z06 center section larger than the Z51 NPP center section, or are they basically the same?
- Are the EOS and Speed Engineering X-pipes true secondary-cat-delete pipes, or are they more of a cat-back/connection pipe behind the factory cats?
- Between EOS and Speed Engineering, which one fits better and has better quality?
- Any drone concerns with Z06 manifolds/primary cats, secondary cat delete, and NPP mufflers?
- Are the Z06 NPP mufflers essentially the same as the Z51 NPP mufflers, or is there any confirmed difference in inlet size or tips?
Any real-world feedback, measurements, or photos would be appreciated.
