H Pipe
Safety Car
Joined: Mar 2017
Posts: 3,768
Likes: 940
From: Orlando Florida
Factory is an H pipe — though the opening in the cross pipe is known to be questionable. If you’re thinking of an x pipe many appreciate the reduction in boat burble, but there is no appreciable power difference.
Last edited by redzg; Aug 4, 2025 at 12:47 PM.
Tech Contributor
Joined: Jan 2007
Posts: 19,422
Likes: 1,146
From: Dyer, IN
Race Director
Joined: Oct 2004
Posts: 12,861
Likes: 4,664
^^^^^^^This^^^^^^^. I once ran Billy Boat 1-3/4" shorties. They did help some according to my trap speeds, but only 1-2mph, maybe. I ran them on my 2000 A4 Vert. The 1997-2000 C5s have more restrictive OEM manifolds. So my slight improvement with the shorties would be even less on the 2001-2004 models. Sell your shorties and go with Kooks or LG long tubes. I went with Kooks 1-7/8 LTs, which covered virtually any hp upgrades I planned in the future. You may lose a bit of low end to lower mid-range torque, but I still recommend 1-7/8. Personal preference, and 1-3/4" tubes will probably be better on a 100% stock engine.
Supporting Vendor
Joined: Nov 2015
Posts: 1,262
Likes: 278
From: Orange County, NY
If you have a corsa "axleback" exhaust, it does not include a midpipe. Just corsa over axle pipes and corsa mufflers/tip assemblies.
__________________
http://www.corvetteexhaustsystems.com
sales@corvetteexhaustsystems.com
201-575-0861 (cell to call or text)
Your Ultimate Resource For Headers, Exhaust Systems & more for Corvette! I carry Corsa, Kooks, ARH, Borla, Billy Boat, Akrapovic, Capristo & Much More
http://www.corvetteexhaustsystems.com
sales@corvetteexhaustsystems.com
201-575-0861 (cell to call or text)
Your Ultimate Resource For Headers, Exhaust Systems & more for Corvette! I carry Corsa, Kooks, ARH, Borla, Billy Boat, Akrapovic, Capristo & Much More
Racer
Joined: Jun 2021
Posts: 257
Likes: 75
I have a '99 with HCI. I have often considered a pair of BBK or BBE shorties to keep passing emissions. They are only $500 or $600 a pair, and they claim to pick up 10-15 HP.. who knows..? But I think there are plenty that would drop $500 on a CAI that produces less than that. 
Having said that, I took my car to my exhaust guy to check the cats to make sure I haven't plugged one up with the cam, and the whole stock exhaust system had zero back pressure on either bank. I told him I wanted to put a Magnaflow cat-back exhaust on it, and he talked me out of it. Basically he said I might pick up a handful of ponies but only at wide open throttle above 6000 rpm. I think the x-pipe is a similar investment. It will change your sound to something more exotic, but for performance, are we talking 4 or 5 horses at redline? Seems like a lot of work and expense to me.
Having said that, I took my car to my exhaust guy to check the cats to make sure I haven't plugged one up with the cam, and the whole stock exhaust system had zero back pressure on either bank. I told him I wanted to put a Magnaflow cat-back exhaust on it, and he talked me out of it. Basically he said I might pick up a handful of ponies but only at wide open throttle above 6000 rpm. I think the x-pipe is a similar investment. It will change your sound to something more exotic, but for performance, are we talking 4 or 5 horses at redline? Seems like a lot of work and expense to me.
Safety Car
Joined: Mar 2017
Posts: 3,768
Likes: 940
From: Orlando Florida
I have a '99 with HCI. I have often considered a pair of BBK or BBE shorties to keep passing emissions. They are only $500 or $600 a pair, and they claim to pick up 10-15 HP.. who knows..? But I think there are plenty that would drop $500 on a CAI that produces less than that.
Having said that, I took my car to my exhaust guy to check the cats to make sure I haven't plugged one up with the cam, and the whole stock exhaust system had zero back pressure on either bank. I told him I wanted to put a Magnaflow cat-back exhaust on it, and he talked me out of it. Basically he said I might pick up a handful of ponies but only at wide open throttle above 6000 rpm. I think the x-pipe is a similar investment. It will change your sound to something more exotic, but for performance, are we talking 4 or 5 horses at redline? Seems like a lot of work and expense to me.
Having said that, I took my car to my exhaust guy to check the cats to make sure I haven't plugged one up with the cam, and the whole stock exhaust system had zero back pressure on either bank. I told him I wanted to put a Magnaflow cat-back exhaust on it, and he talked me out of it. Basically he said I might pick up a handful of ponies but only at wide open throttle above 6000 rpm. I think the x-pipe is a similar investment. It will change your sound to something more exotic, but for performance, are we talking 4 or 5 horses at redline? Seems like a lot of work and expense to me.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Melting Slicks
Joined: Aug 2003
Posts: 2,000
Likes: 1,333
From: Des Plaines, Il
^^^^^^^This^^^^^^^. I once ran Billy Boat 1-3/4" shorties. They did help some according to my trap speeds, but only 1-2mph, maybe. I ran them on my 2000 A4 Vert. The 1997-2000 C5s have more restrictive OEM manifolds. So my slight improvement with the shorties would be even less on the 2001-2004 models. Sell your shorties and go with Kooks or LG long tubes. I went with Kooks 1-7/8 LTs, which covered virtually any hp upgrades I planned in the future. You may lose a bit of low end to lower mid-range torque, but I still recommend 1-7/8. Personal preference, and 1-3/4" tubes will probably be better on a 100% stock engine.
Instructor
Joined: Apr 2021
Posts: 234
Likes: 82
From: Mobile
Another option is ls7 manifolds and downpipes. I've seen them real cheap once in a while. LS7 don't get much of a benefit with LT they are so good and different than ls3. As I have 2000's I considered them and shorties rather than buying 2001's but ended up with Maximizer LT and x-pipe from a closeout for $170.
Last edited by CFight; Aug 13, 2025 at 11:11 PM.