Exhaust manifold tubes
Thread Starter
Cruising
Joined: Jul 2020
Posts: 13
Likes: 1
Exhaust manifold tubes
I don't know whether this the right forum to bring this up, I'm a new user and would like to ask a question.
I have a 1990 corvette, L98, and I would like to know what are those tubes that are welded on top of the exhaust manifold for, and what they connect to?
I want to change the headers, not stock but don't know if I need to get the same type of headers,. Thanks
I have a 1990 corvette, L98, and I would like to know what are those tubes that are welded on top of the exhaust manifold for, and what they connect to?
I want to change the headers, not stock but don't know if I need to get the same type of headers,. Thanks
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Tubes
Those are the tubes the smog pump blows air into that reignites any un burned exhaust.
theoretically, the combustion process takes longer than The piston dwells at power cycle, and it’s still burning when the exhaust valve opens.
so you blow fresh air in there, and the unburned hot gasses continue the burn cycle in the exhaust manifold.
i wouldn’t advise removing them if you go through some type of visual inspection at your smog checks.
the smog pump uses about 3 hp. So taking it off, you won’t feel an increase.
they do make cams that make the smog pump unnecessary, but for smog check peace of mind, use headers that have the tubes.
also if you chosen-to remove the smog pump and tubes, keep all of it because the next guy that buys your car will have to put it back on, and will pay you less for the car without it.
theoretically, the combustion process takes longer than The piston dwells at power cycle, and it’s still burning when the exhaust valve opens.
so you blow fresh air in there, and the unburned hot gasses continue the burn cycle in the exhaust manifold.
i wouldn’t advise removing them if you go through some type of visual inspection at your smog checks.
the smog pump uses about 3 hp. So taking it off, you won’t feel an increase.
they do make cams that make the smog pump unnecessary, but for smog check peace of mind, use headers that have the tubes.
also if you chosen-to remove the smog pump and tubes, keep all of it because the next guy that buys your car will have to put it back on, and will pay you less for the car without it.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
the smog pump uses about 3 hp. So taking it off, you won’t feel an increase.
