Pancake Air Cleaner
 

How restrictive was the pancake air cleaners used on the 67 Firebird,' especially the one used with the Q-jet?

very on the 67 i had. I could ''feel,'' a slight power loss or atleast i thought so. It may have been sound related too? I would swap it on a shows and drive with an open element and chrome lid. The surface area of the stock element is roughly 1/3 a standard 14x3 element. It has to have some effect in my opinon
i do like how they look though.

My 67 GTO runs cooler with a larger open air filter versus the pancake air set up

All of those really closed-off air cleaners are terrible. Check out the Air Filter Shootout episode of Engine Masters on the Motortrend app, they do a huge comparison. (you can also find bootlegs on the google)

Other than the ridiculous ones, the open-top air filters are the least restrictive. https://www.summitracing.com/parts/e...RoC6rYQAvD_BwE

Very interesting.