Mufflers
Thread Starter
Instructor
Joined: Apr 2007
Posts: 143
Likes: 0
Mufflers
What would happen if I took out the cat. converter and ran split straight pipes to rear mufflers? Will the computer flip over with out that back pressure?
Chuck
1985 is the year
Chuck
1985 is the year
Last edited by Dryoo7; Mar 7, 2011 at 07:30 PM. Reason: Left out year of car
Instructor
Joined: Aug 2008
Posts: 249
Likes: 0
From: Pasadena CA
I think back pressure wouldn't be your issue, you don't really need any back pressure at all, however you'll have a tough time passing emissions in some states and, to be honest I don't know for sure how important the 02 sensor is to the l98, (if it even affects it at all.)
You'll also have a tought time finding a shop that'll remove your cat if you're in CA
You'll also have a tought time finding a shop that'll remove your cat if you're in CA
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
My 87 has true duals (2 1/4" pipe) and an X-pipe where the cat used to sit. Mufflers are DynoMax Ultra-Flo Race mufflers. At cruise speeds (low RPM) the car is fairly quiet until it goes WOT. I added the X-pipe last year because the configuration would have gotten me bounced out at PIR on weekday track days. There is a 95dB max noise level there and with the pipes and mufflers and no X-pipe, the car was much louder than that.
I did pick up some HP on the higher end and a little more torque at mid-RPM. I still have the factory manifolds but a set of headers would be another improvement and the whole exhaust setup could be worth 20-some HP.
One thing you do have to watch is emissions. Like WA, Oregon has lots of areas where emissions testing is not required. But it may be very difficult to get a local muffler shop to install true duals or even remove the cat. If they get caught, the EPA can levy a 5-figure fine
So do the trailer and no plate trick.
I did pick up some HP on the higher end and a little more torque at mid-RPM. I still have the factory manifolds but a set of headers would be another improvement and the whole exhaust setup could be worth 20-some HP.
One thing you do have to watch is emissions. Like WA, Oregon has lots of areas where emissions testing is not required. But it may be very difficult to get a local muffler shop to install true duals or even remove the cat. If they get caught, the EPA can levy a 5-figure fine
So do the trailer and no plate trick.
Race Director
Joined: Nov 2003
Posts: 12,220
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
You'll also still be legal -- if necessary.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski