Yeah, you want really know till you put the rest of the exhaust on.
The time frame: I know there's a lot of variables from car to car, was just looking for something to ~ go by.
I just tested the fan on a bench today, & it appears to move more air than my twin SPA's in My Cuda. That's what I was hoping for. Wish I had an Anemometer. I know speed & volume are 2 different things.