3.8 Computer Controls What?

[megaladon6]

the casting of a v6 quadrajet and thus the max CFM is the same as the v8 quadrajets. they use the air valves and secondary stops to limit the airflow. that's why you should be able to use a v8 carb. and i highly doubt that the q-jet primary is the same as the dualjet. the jets and metering rods, along with the idle air system would have to be different.

 

[Peter]

the casting of a v6 quadrajet and thus the max CFM is the same as the v8 quadrajets. they use the air valves and secondary stops to limit the airflow. that's why you should be able to use a v8 carb. and i highly doubt that the q-jet primary is the same as the dualjet. the jets and metering rods, along with the idle air system would have to be different.

I'm almost positive that the primary sideof the 4.1 qjet is the same as my current 3.8 carb

http://tech.oldsgmail.com/buick_mod.php

 

[joe_padavano]

the casting of a v6 quadrajet and thus the max CFM is the same as the v8 quadrajets. they use the air valves and secondary stops to limit the airflow. that's why you should be able to use a v8 carb. and i highly doubt that the q-jet primary is the same as the dualjet. the jets and metering rods, along with the idle air system would have to be different.

I'm almost positive that the primary sideof the 4.1 qjet is the same as my current 3.8 carb

http://tech.oldsgmail.com/buick_mod.php

The primary side of a Qjet is the same as the dual jet 2bbl, however the dual jet (and the computer controlled Qjet on the 305 and 307) use a mixture control solenoid to control the air/fuel ratio. There is also a throttle position sensor that is used by the computer for a number of functions. As noted above, the computer controls the mixture ratio, the spark advance, and the trans lockup. That's about it on an 82. Your A/C compressor clutch does not run through the computer; it uses a throttle switch instead so that's not a problem. The computer also controls the EGR valve, the idle speed, and the evap canister purge. If you plan to eliminate these items then there's no problem.

Removing the computer requires you to use a non-computer carb and distributor and some external method of converter lockup. That's about it.

 

[Peter]

the casting of a v6 quadrajet and thus the max CFM is the same as the v8 quadrajets. they use the air valves and secondary stops to limit the airflow. that's why you should be able to use a v8 carb. and i highly doubt that the q-jet primary is the same as the dualjet. the jets and metering rods, along with the idle air system would have to be different.

I'm almost positive that the primary sideof the 4.1 qjet is the same as my current 3.8 carb

http://tech.oldsgmail.com/buick_mod.php

The primary side of a Qjet is the same as the dual jet 2bbl, however the dual jet (and the computer controlled Qjet on the 305 and 307) use a mixture control solenoid to control the air/fuel ratio. There is also a throttle position sensor that is used by the computer for a number of functions. As noted above, the computer controls the mixture ratio, the spark advance, and the trans lockup. That's about it on an 82. Your A/C compressor clutch does not run through the computer; it uses a throttle switch instead so that's not a problem. The computer also controls the EGR valve, the idle speed, and the evap canister purge. If you plan to eliminate these items then there's no problem.

Removing the computer requires you to use a non-computer carb and distributor and some external method of converter lockup. That's about it.

wow that was very helpful, thanks a bunch

 

[85 Cutlass Brougham]

The V6 Quadrajet has the same main body and throttle plates, but the secondary air valve door stop is much longer, thus cutting it down to around 450-500cfm. Despite what people may think, there ARE different size Quadrajets for different applications, they just limit air flow by reducing the secondary air valve door's maximum opening and not by changing the throttle plate sizes. This also means you can very easily modify any Quadrajet to the maximum size by simply cutting down the little stop on the shaft with a Dremel.