[U47]

There is a interesting story about the T/A shaker hood and why that shouldn't be there ( open or closed) by the guy who was head of Pontiac design studio. Find it in the October 2017 issue of Collectible Automobile

[72projectbird]

Originally Posted by U47

There is a interesting story about the T/A shaker hood and why that shouldn't be there ( open or closed) by the guy who was head of Pontiac design studio. Find it in the October 2017 issue of Collectible Automobile

Didn't the engineers originally want the Formula hood on the T/A?

[U47]

Originally Posted by 72projectbird

Didn't the engineers originally want the Formula hood on the T/A?

Yes, if you take the Formula hood scoops and opened them up you have no hood wind interference from the hood because it's raised and far forward. In order for the shaker to work, it's reverse scoop would have to reach far back to the high pressure area near the windshield.
After wind tunnel test pressure profiles showed the shaker in the wrong place and that air would actually come out of the open scoop instead of going in.

[U47]

A open shaker would be sucking the air out of the air cleaner. That's why you can hear those secondary's so well.
It was Bill Porter that got his hands on the F body wind tunnel evaluation from Vultee in Texas. The report was about 1/2 " thick page after page of where to put spoilers how big they should be. Where all the pressure profiles were, all the places where you wanted to let air in and let it out.

[Super Duty D]

By 73' all shakers were closed because of new noise restriction laws. They had to close it and the glorious sounds of your secondaries kicking in. 2 of 4 TA's open here.

[burd]

Here's the Article, 1983. Same issue has hopping upon the 403 article in it.

[GT182]

I had a 79 Formula and wished the scoops were open. I also wished it had the TA fenders too. I miss that car. Someday I might look for another one..... if I sell the Goat.

[burd]

here