David said when at warm idle I should just have a bit of vacuum at the breather on the can. With the breather pulled, I can't really feel vacuum with my hand but a piece of tissue confirms there is just a bit of vacuum pulling through the breather. I flushed the cooling system several times today and finished up a few other odds and ends...then beat on the car for a bit after several road tests. I lost 150 RPM at idle...
Which is fantastic as the car has always idled fast. Now it idles at a rock steady 810-830 RPM instead of the 970-1020 RPM. No sign of oil out the pass side breather yet, big test will be track day Thursday night.
Here's a little video of me testing out my other favorite off season upgrade. Anyone guess what it is...?
https://youtu.be/AmerrpIqFDo
I'll update how the catch can did after Track Night in America on the newly paved Heartland Park Topeka road course Thursday.