C3 side exhaust question
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Instructor
Joined: Jul 2023
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C3 side exhaust question
I bought a C3 with factory side exhaust installed. I seem to get alot of exhaust fumes in the car with the windows down. Is this normal? I realize the exhaust tip is right under the door but it's a little unbearable
1967 Pedal Car Champion
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From: US-PNW
When you say factory exhaust, you have a '69? That's the only C3 year that factory side exhaust was available.
If indeed the factory system, then no, not normal. Have you inspected the pipes themselves to ensure there are no rusted areas under the door sills?
Does the exhaust burn your eyes?
If indeed the factory system, then no, not normal. Have you inspected the pipes themselves to ensure there are no rusted areas under the door sills?
Does the exhaust burn your eyes?
Le Mans Master
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Instructor
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I have a 69 with factory side exhaust. It had noticeable exhaust fumes at the time of purchase nearly 13 years ago. It also had a myriad of carb issues. After setting up the carb correctly following Lars papers as well as timing, plugs, points etc. the fumes are now gone.
Is my vette stock?? HAHA
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Tune your carb. You will have zero issues. Ive had mine on for the 8 years I've owned the car with zero fumes
Thread Starter
Instructor
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I might shoot the lock off the wallet and get a new set of pipes. Thinking about these
https://highfloperformance.com/produ...t-with-c2-tips
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From: Virginia
What is your timing set to?
I can smell my exhaust, but it isn't offensive, and my eyes certainly aren't burning.
Please post a photo! If you have the stock-69-style covers, that look is pretty cool and worth keeping. And we all like to see it.
I can smell my exhaust, but it isn't offensive, and my eyes certainly aren't burning.
Please post a photo! If you have the stock-69-style covers, that look is pretty cool and worth keeping. And we all like to see it.
Thread Starter
Instructor
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The pipes look like this. There are three pot metal pieces bolted to a plastic/ fiberglass insulator
Is my vette stock?? HAHA
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From: Im not allowed to tell you
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i cant get a good reading with my wideband. The exhaust must be sucking air from somewhere. I tuned it the old fashioned way with a vacuum gauge. I got it from 15 in/hg to 18 in/hg. Lets see if that helps. I can't tell if my eyes are burning because it's way lean or too fat
I might shoot the lock off the wallet and get a new set of pipes. Thinking about these
https://highfloperformance.com/produ...t-with-c2-tips
I might shoot the lock off the wallet and get a new set of pipes. Thinking about these
https://highfloperformance.com/produ...t-with-c2-tips
Last edited by Rescue Rogers; Aug 22, 2023 at 05:29 AM.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,209
Likes: 9,347
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
i cant get a good reading with my wideband. The exhaust must be sucking air from somewhere. I tuned it the old fashioned way with a vacuum gauge. I got it from 15 in/hg to 18 in/hg. Lets see if that helps. I can't tell if my eyes are burning because it's way lean or too fat
I might shoot the lock off the wallet and get a new set of pipes. Thinking about these
https://highfloperformance.com/produ...t-with-c2-tips
I might shoot the lock off the wallet and get a new set of pipes. Thinking about these
https://highfloperformance.com/produ...t-with-c2-tips
Is your wide band jumping from lean to rich...if so you may have a vacuum leak around the carb or the intake to head seal. Mine jumped a bit until I used a bit of Forma gasket #2 on both sides of my intake gasket
Race Director
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From: Virginia
Looks nice!
A "Lars" style tune could really wake up your engine. He ( @lars ) has posted lots of threads on this Forum. Email, (don't PM) and ask for his timing papers, and his Q-Jet papers. Getting your timing properly advanced might keep your eyes from watering. Then you can adjust the carb. But fix the timing first!
One recent example with his email address:
https://www.corvetteforum.com/forums...lp-needed.html
A "Lars" style tune could really wake up your engine. He ( @lars ) has posted lots of threads on this Forum. Email, (don't PM) and ask for his timing papers, and his Q-Jet papers. Getting your timing properly advanced might keep your eyes from watering. Then you can adjust the carb. But fix the timing first!
One recent example with his email address:
https://www.corvetteforum.com/forums...lp-needed.html
Thread Starter
Instructor
Joined: Jul 2023
Posts: 103
Likes: 109
Looks nice!
A "Lars" style tune could really wake up your engine. He ( @lars ) has posted lots of threads on this Forum. Email, (don't PM) and ask for his timing papers, and his Q-Jet papers. Getting your timing properly advanced might keep your eyes from watering. Then you can adjust the carb. But fix the timing first!
One recent example with his email address:
https://www.corvetteforum.com/forums...lp-needed.html
A "Lars" style tune could really wake up your engine. He ( @lars ) has posted lots of threads on this Forum. Email, (don't PM) and ask for his timing papers, and his Q-Jet papers. Getting your timing properly advanced might keep your eyes from watering. Then you can adjust the carb. But fix the timing first!
One recent example with his email address:
https://www.corvetteforum.com/forums...lp-needed.html
Timing is right on the money. Carb is freshly restored. Just have to fix the exhaust so I get get an accurate AFR. The plugs are new and still have no color on them which leads me to believe it's way lean.
Race Director
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From: Virginia
https://en.wikipedia.org/wiki/Lars_Grimsrud
Burning Brakes
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It can't hurt to get a second opinion, especially if you set your timing at idle. But don't take my word for it.
https://en.wikipedia.org/wiki/Lars_Grimsrud
https://en.wikipedia.org/wiki/Lars_Grimsrud
Thread Starter
Instructor
Joined: Jul 2023
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It can't hurt to get a second opinion, especially if you set your timing at idle. But don't take my word for it.
https://en.wikipedia.org/wiki/Lars_Grimsrud
https://en.wikipedia.org/wiki/Lars_Grimsrud
I usually set my QJets up to run around 13.0- 13.2 AFR at idle and cruise. I have a wideband O2 which is an invaluable data point. I also read the plugs. I'm also a big believer in giving the engine what it wants rather than living and dying by what the service manual says
Dr. Detroit
Joined: Mar 2012
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From: New Braunfels Texas
Geez...where's my Wikipedia page?? Lol. I'm sure Lars is great with QJets.
I usually set my QJets up to run around 13.0- 13.2 AFR at idle and cruise. I have a wideband O2 which is an invaluable data point. I also read the plugs. I'm also a big believer in giving the engine what it wants rather than living and dying by what the service manual says
I usually set my QJets up to run around 13.0- 13.2 AFR at idle and cruise. I have a wideband O2 which is an invaluable data point. I also read the plugs. I'm also a big believer in giving the engine what it wants rather than living and dying by what the service manual says
None of us tuners or engine builders here go by the service manual for tuning......and yes, you give the engine what it wants. 10 degrees at idle isn't enough.......and none of us here set timing at idle......you set it at or around 3000 rpm and shoot for 36-38 degrees......the idle timing is what it is.....you record it, but it isn't that important.....most times the initial falls at 15 degrees shooting for 36 total......you do not drive at idle, there is no load, so idle timing is insignificant, but it plays a role in how much total timing you have.....
The 69' Side Exhaust is terribly restrictive....especially behind a big block....(assuming 454)......those pipes on there now will sap about 30-40 horsepower compared to a free flowing setup......definitely look at something else.....
Jebby
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[QUOTE=Jebbysan;160696689
The 69' Side Exhaust is terribly restrictive....especially behind a big block....(assuming 454)......those pipes on there now will sap about 30-40 horsepower compared to a free flowing setup......definitely look at something else.....
Jebby[/QUOTE]
That is why I had Allen's build me a set in 2-1/2" and they are much louder...which means they are flowing more air...which means they are allowing the engine to develop more power. All good!
The 69' Side Exhaust is terribly restrictive....especially behind a big block....(assuming 454)......those pipes on there now will sap about 30-40 horsepower compared to a free flowing setup......definitely look at something else.....
Jebby[/QUOTE]
That is why I had Allen's build me a set in 2-1/2" and they are much louder...which means they are flowing more air...which means they are allowing the engine to develop more power. All good!