Cut outs,performance, engine damage?
Thread Starter
8th Gear
Joined: Jun 2010
Posts: 8
Likes: 0
From: Racine WI
Cut outs,performance, engine damage?
Can anyone tell me if putting cutouts on my stock C6 (z51) will cause problems with air fuel mixture, and or O2 sensor damage. I know from working with dirtbikes and sportbikes that if you alter intake or exhaust you need to re-jet. If the air fuel mixtures get out of balance you will load up rings, valve seats, and carbon up the pistons. Will the ecu take care of those things with open exhaust, and then re-correct when you close them?
Why are headers considered illegal? If you install cats and mufflers and use the O2 sensors aren't you just making the engine more efficient? I can understand through-flow cats being a problem, but can you not maintain legal emissions standards and still get more efficiency /performance?
Why are headers considered illegal? If you install cats and mufflers and use the O2 sensors aren't you just making the engine more efficient? I can understand through-flow cats being a problem, but can you not maintain legal emissions standards and still get more efficiency /performance?
Le Mans Master
Joined: Oct 2007
Posts: 6,149
Likes: 11
From: Greater Detroit Metro MI, when I'm not travelling.
Can anyone tell me if putting cutouts on my stock C6 (z51) will cause problems with air fuel mixture, and or O2 sensor damage. I know from working with dirtbikes and sportbikes that if you alter intake or exhaust you need to re-jet. If the air fuel mixtures get out of balance you will load up rings, valve seats, and carbon up the pistons. Will the ecu take care of those things with open exhaust, and then re-correct when you close them?
Why are headers considered illegal? If you install cats and mufflers and use the O2 sensors aren't you just making the engine more efficient? I can understand through-flow cats being a problem, but can you not maintain legal emissions standards and still get more efficiency /performance?
There is no such thing as legal long tube headers.
Melting Slicks
Joined: Oct 2010
Posts: 2,314
Likes: 4
From: Cape May, NJ; Guntersville, AL; Orange Beach, AL
That only really happens with two-stroke engines. The Corvette, being a 4-stroke, sees virtually no change in AFR from different exhausts.
High flow cats are less efficient, not more. Moving the cats away from their stock location, even stock cats, is illegal because by placing them further away from the engine they take longer to warm up and cold start emissions are increased.
There is no such thing as legal long tube headers.
High flow cats are less efficient, not more. Moving the cats away from their stock location, even stock cats, is illegal because by placing them further away from the engine they take longer to warm up and cold start emissions are increased.
There is no such thing as legal long tube headers.
What PL said.
Thread Starter
8th Gear
Joined: Jun 2010
Posts: 8
Likes: 0
From: Racine WI
Well that kinda sucks. The heat and the distance discussion makes sense. Thanks for the info.
I guess I've spent a lot of money in my life re-jetting four strokes because I put performance pipes on them. Or maybe those tricky Italians put a two-stroke in my Ducati.
I want to take my vette to Road America for a track day the end of April. I would like to be able to hear and feel the engine better, but I also need it to pass emissions testing.
I guess in the long run the cut-outs I'm thinking about are illegal too.
I guess I've spent a lot of money in my life re-jetting four strokes because I put performance pipes on them. Or maybe those tricky Italians put a two-stroke in my Ducati.
I want to take my vette to Road America for a track day the end of April. I would like to be able to hear and feel the engine better, but I also need it to pass emissions testing.
I guess in the long run the cut-outs I'm thinking about are illegal too.
Speedy
Joined: Mar 2007
Posts: 6,114
Likes: 931
From: Tn
2024 C8 of the Year Finalist - Modified
Well that kinda sucks. The heat and the distance discussion makes sense. Thanks for the info.
I guess I've spent a lot of money in my life re-jetting four strokes because I put performance pipes on them. Or maybe those tricky Italians put a two-stroke in my Ducati.
I want to take my vette to Road America for a track day the end of April. I would like to be able to hear and feel the engine better, but I also need it to pass emissions testing.
I guess in the long run the cut-outs I'm thinking about are illegal too.
I guess I've spent a lot of money in my life re-jetting four strokes because I put performance pipes on them. Or maybe those tricky Italians put a two-stroke in my Ducati.
I want to take my vette to Road America for a track day the end of April. I would like to be able to hear and feel the engine better, but I also need it to pass emissions testing.
I guess in the long run the cut-outs I'm thinking about are illegal too.
Le Mans Master
Joined: Oct 2007
Posts: 6,149
Likes: 11
From: Greater Detroit Metro MI, when I'm not travelling.
Well that kinda sucks. The heat and the distance discussion makes sense. Thanks for the info.
I guess I've spent a lot of money in my life re-jetting four strokes because I put performance pipes on them. Or maybe those tricky Italians put a two-stroke in my Ducati.
I want to take my vette to Road America for a track day the end of April. I would like to be able to hear and feel the engine better, but I also need it to pass emissions testing.
I guess in the long run the cut-outs I'm thinking about are illegal too.
I guess I've spent a lot of money in my life re-jetting four strokes because I put performance pipes on them. Or maybe those tricky Italians put a two-stroke in my Ducati.
I want to take my vette to Road America for a track day the end of April. I would like to be able to hear and feel the engine better, but I also need it to pass emissions testing.
I guess in the long run the cut-outs I'm thinking about are illegal too.
I believe cutouts are legal so long as they are closed.
Thread Starter
8th Gear
Joined: Jun 2010
Posts: 8
Likes: 0
From: Racine WI
Racine does not do visual inspections. They use to roll a mirror around underneath the car but I haven't seen them do that lately. It probably wouldn't fit under the vette anyway.
Here's some of my concerns;
Headers, cats, and the cross over pipes, $1500-$1600
Tune $450 the first time $350 each time after. Tuner is about 60mi away.
I do the installation myself. I don't have a lift but have lots of experience and ingenuity .
Still have stock mufflers - don't want an exhaust with an attitude because I like this car and want to drive it - like cross country and stuff. I have a few bikes with attitude if I want that.
Install cutouts - I do the install parts $425
I go to for emissions testing and have a problem. (go to the tuner?)
What about down the road? ... pay the tuner $350 to try to help me out?
Header manufacturers strongly advise getting a tune after the install. I figure the engine runs lean because of the decrease in back pressure. I think maybe just to match fuel, timing, etc to the newly found effects of the headers / cats / x pipes. If you don't do the tune you don't get the power you paid for, you don't pass an inspection, you quite possibly damage the engine.
It's just my logic at work and maybe I'm wrong.
Here's some of my concerns;
Headers, cats, and the cross over pipes, $1500-$1600
Tune $450 the first time $350 each time after. Tuner is about 60mi away.
I do the installation myself. I don't have a lift but have lots of experience and ingenuity .
Still have stock mufflers - don't want an exhaust with an attitude because I like this car and want to drive it - like cross country and stuff. I have a few bikes with attitude if I want that.
Install cutouts - I do the install parts $425
I go to for emissions testing and have a problem. (go to the tuner?)
What about down the road? ... pay the tuner $350 to try to help me out?
Header manufacturers strongly advise getting a tune after the install. I figure the engine runs lean because of the decrease in back pressure. I think maybe just to match fuel, timing, etc to the newly found effects of the headers / cats / x pipes. If you don't do the tune you don't get the power you paid for, you don't pass an inspection, you quite possibly damage the engine.
It's just my logic at work and maybe I'm wrong.
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 266
From: St. Louis, MO
St. Jude Donor '08
I'm a fan of cutouts.
I've had QTP cutouts for years and love them. The flow being redirected at the ground gives the car an old school rumble.
Another option is the Z06 mufflers with the built in cutouts. You can buy them used, then buy NPP in Box from Nakidparts, and have the beauty of stock quiet or open loud at your wish.
Another option is the Z06 mufflers with the built in cutouts. You can buy them used, then buy NPP in Box from Nakidparts, and have the beauty of stock quiet or open loud at your wish.
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Speedy
Joined: Mar 2007
Posts: 6,114
Likes: 931
From: Tn
2024 C8 of the Year Finalist - Modified
