NPP exhaust diameter?
Thread Starter
Race Director
Joined: Jan 2014
Posts: 10,709
Likes: 7,101
From: Fulshear, TX
NPP exhaust diameter?
I vaguely recall reading at one point that the base exhaust is 2.5" while the NPP is 2.75". Can anyone say with certainty what the diameter is? Thank you!
The reason I ask is because Borla's bolt-on X-pipe is 2.75" while Corsa's is 3.0". I'm in the process of buying the Corsa, but still curious.
The reason I ask is because Borla's bolt-on X-pipe is 2.75" while Corsa's is 3.0". I'm in the process of buying the Corsa, but still curious.
Thread Starter
Race Director
Joined: Jan 2014
Posts: 10,709
Likes: 7,101
From: Fulshear, TX
I've spent quite a bit of time reading through installs and looking at pictures. What I've gathered so far is that the stock X-pipe and axle-back exhaust piping is somewhere in the realm of 2.50-2.75" in diameter.
The Borla X-pipe basically looks like a stock X-pipe, minus the cats, with a little smoother bends; diameter looks similar.
The Borla X-pipe basically looks like a stock X-pipe, minus the cats, with a little smoother bends; diameter looks similar.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
My car has a custom fabricated exhaust --NON NPP and we used 2.5" piping to match up
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The LT1 is backed by a choice of active exhaust systems that are less restrictive than the previous generation, due in part to an increase in diameter from 2.5 inches to 2.75 inches. The standard system offers a 13-percent improvement in airflow and features a pair of butterfly valves that contribute to greater refinement at cruising speeds when the engine is operating in fuel-saving V-4 mode.