Hanslow

I thought some credence was given a while back to the speed issue on pre bug eye Imprezas and air flow? Sure someone did some tests and found that at a certain speed the impact speed of the air on the front leading edge of the bonnet was sufficient to make the boundary layer actually go over the leading edge of the bonnet scoop and hence they saw a massive increase in intake temperatures? At speeds leading up to that happening, all the air was being forced to the back of the intercooler without a third party internal splitter installed. Part of the reason (I thought) why the bonnet scoop is now the massive monstrosity it is now, to capture air at higher speeds.

Gear Head

iTrader: (2)

The the new shape sti has a smaller scoop than the sti 8?

Hanslow

Quite possibly to do with the redesigned bonnet which allows for more parallel flow and so having a lower boundary layer at faster speeds. It's a trade off too between drag and amount of air caught in the scoop.

Would need to either try it in a wind tunnel, or model it in some CFD software. Don't have access to a wind tunnel and have no time to be producing accurate models of different bonnet and scoop stylings in software

Best do a search on here for intake temps, bonnet scoops, etc. as it's been covered a few years back.

As far as I recall, the problem, if indeed there is/was one, was down to prolonged high speed driving where the intake temps were a lot higher for a long period of time. Short bursts weren't thought to be as much of an issue.

It's touched on in this post here (with some respected names from yesteryear....) https://www.scoobynet.com/drivetrain...go-scoobs.html

blueangel

Don't waste yer time,the guy's a total dik.