Secondary air flaps

[Jeffs68]

Is there any performance advantage to the secondary air flaps that have notches cut out of them as opposed to the ones that don't.

[carmantx]

Depends on location of the POE, and engine/driving desire.  Some POE are under the valve and no need to slot.  Some are in line with the valve and again no need to slot.
In my experience, the secondaries can come in quicker and smoother with modified air valves.  Pontiac made the big slots in theirs.  They seem a little larger than needed.

[Jeffs68]

Thanks for the info

[Jeffs68]

Just an update/FYI, I had a very slight delay going WOT, and the trans dropped down with a nice jolt (2 speed), adjusted the  tension on the secondary air flap spring about 1/3 turn. It seem a bit too tight, but after the test drive, no delay and a nice smooth transition when the trans drops to LO.

[Jeffs68]

Just to clarify, I increased the tension on the spring by 1/3 turn.

[Cliff Ruggles]

The secondary springs get weak and the plastic cams wear out.  I see a LOT of carbs in here with the springs wound too tight and ruined.  If you find yourself adjusting the spring past a full turn it's time for a new one.

Another big issue we've seen in recent years is the white plastic pull-offs currently being offered open too quickly.  We modify every one we sell to slow them down some. 

If the pull-off is too fast it requires too much spring tension to smooth transition.....Cliff