Hollowing out cats
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Re: Hollowing out cats (ld85)
I've done it before-but it is generally illegal. I just took a hammer and small diameter pipe and knocked everything out, cat was plugged, car ran fine. :thumbs:
Team Owner
Joined: Sep 2003
Posts: 25,295
Likes: 4
From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
Re: Hollowing out cats (rtracy)
It wont hurt the O2 sensors a bit. I just made some J-pipes and removed the CATs. Of course I added the O2 bungs for the sensors. :cheers:
Team Owner
Joined: Sep 2003
Posts: 25,295
Likes: 4
From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
Re: Hollowing out cats (rtracy)
What are o2 bungs?
O2 bungs are what hold the o2 in place. What you screw your O2 sensor into. :yesnod:
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Racer
Joined: Feb 2004
Posts: 265
Likes: 1
From: Irwindale Ca
Re: Hollowing out cats (VictorRussell'92)
You will get more horsepower. Thats the only difference I saw. I hollowed out the precats. All they were doing is destroying my main cat. I left my main cat in the car to help pass smog. The car runs fine and passes smog :hurray:
Le Mans Master
Joined: Feb 2000
Posts: 9,058
Likes: 214
From: Epping NH
Re: Hollowing out cats (rtracy)
If you hollow out the cats without putting a straight pipe inside then the larger area in the cat will decrease flow velocity causing flow stagnation, and decreasing bottom end power. If you cat was fine to begin with they you'll reduce your performance by an hp or 2. The only time hollowing out a cat increases performance is when the original cat was in bad shape to begin with (IE clogged).
Ask any exhaust system guru and they'll this is exactly what they will tell you.
[Modified by bac22, 10:44 AM 3/16/2004]
Ask any exhaust system guru and they'll this is exactly what they will tell you.
[Modified by bac22, 10:44 AM 3/16/2004]
Team Owner
Joined: Sep 2003
Posts: 25,295
Likes: 4
From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
Re: Hollowing out cats (bac22)
If you hollow out the cats without putting a straight pipe inside then the larger area in the cat will decrease flow velocity causing flow stagnation, and decreasing bottom end power. If you cat was fine to begin with they you'll reduce your performance by an hp or 2. The only time hollowing out a cat increases performance is when the original cat was in bad shape to begin with (IE clogged).
Ask any exhaust system guru and they'll this is exactly what they will tell you.
[Modified by bac22, 10:44 AM 3/16/2004]
Ask any exhaust system guru and they'll this is exactly what they will tell you.
[Modified by bac22, 10:44 AM 3/16/2004]
So install J-pipe like I said. And I'm calling :bs on anyone who says removing your CATs properly wont increase HP. :p:
Team Owner
Joined: Sep 2003
Posts: 25,295
Likes: 4
From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
Re: Hollowing out cats (rtracy)
We have visual inspections so I can't just put a pipe in it's place. It has to apear that it is there.
