Removing Smog Control
Thread Starter
1st Gear
Joined: Aug 2006
Posts: 1
Likes: 0
Removing Smog Control
My son just bought an 81 and his county doesn't require an emissions test for cars 25 years old. Obviously the pump needs to go and much of the emission valves and hoses. Should he change or rebuild the Q4 carburetor? Is the stock manifold decent for street? Any recommendation on headers? How about distributor and control module?
Compression check indicated 175 lbs on 6 cylinders, 165 on the other two.
He's not intending to race. The car will be used for daily transportation.
Appreciate any comments or suggestions,
StreamDancer
Compression check indicated 175 lbs on 6 cylinders, 165 on the other two.
He's not intending to race. The car will be used for daily transportation.
Appreciate any comments or suggestions,
StreamDancer
Safety Car
Joined: Dec 2004
Posts: 4,876
Likes: 1
From: Jersey Shore Exit 98
[QUOTE=StreamDancer]My son just bought an 81 and his county doesn't require an emissions test for cars 25 years old. Obviously the pump needs to go and much of the emission valves and hoses. Should he change or rebuild the Q4 carburetor? Is the stock manifold decent for street? Any recommendation on headers? How about distributor and control module?
If everything is hooked up correctly and the car is running good why remove it? Your not going to see any great horse power gains..
I would leave the engine as is and add a set of hooker headers & true dual 2 1/2 inch exhaust w/a pair of performance mufflers. This setup will give you 25 more ponies and make the car sound like a corvette should.
If everything is hooked up correctly and the car is running good why remove it? Your not going to see any great horse power gains..
I would leave the engine as is and add a set of hooker headers & true dual 2 1/2 inch exhaust w/a pair of performance mufflers. This setup will give you 25 more ponies and make the car sound like a corvette should.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
first and best $$ spent. The carb should only be rebuilt if its not working, if the car is running ok, just clean it up and goIf you do go with the headers, be sure they put the O2 sensor back in the new pipe on the drivers side, it is one of the main inputs to the ECM to control the AF mixture, along with the TPS (Throttle Position Sensor) and other items.
Burning Brakes
Joined: Feb 2006
Posts: 841
Likes: 0
From: High Desert California
i don't know if you're ready for something like this. i took all of that out of my car and had to take the computer off too, changed the distributor, carb, and a lot of hoses need to go and it's a PIA to trace them. converter lock up switch too is needed. like what most people are saying, if it's working fine, i would leave it.
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Unless you're pretty decent with mechanical knowledge, I wouldn't tinker with all of that stuff right off the bat. Learn a little more about it THEN decide if you want to remove it. Easiest gain in power and gas mileage is to yank the stupid stock exhaust and go with sidepipes. It's actually easier to do sidepipes than it is to do true duals to the back, on an '81. That crossmember is a little bastard, unless you change it. Sidepipes will also keep heat away from your rear spring and keep it living longer.
Honestly, the first thing you should do is rebuild the suspension and replace the shocks and springs.
Honestly, the first thing you should do is rebuild the suspension and replace the shocks and springs.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
The AIR injection pump is the only thing you really want to pull if you go with headers and duals. It comes off with 3 or 4 bolts which you will have to replace on the waterpump. The control valves all come off in one piece and then cap 2 vac lines on the carb.
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
The car is computer controlled. Do not remove the emissions stuff unless you know what you are doing. The computer will be going full rich at all times, fouling plugs and reducing drivability.
Not to mention burning up the cat convertor.
Don't mess with it. If he's not racing then why would you wanna change it?
Not to mention burning up the cat convertor.
Don't mess with it. If he's not racing then why would you wanna change it?
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