Anyone happen to know what the vacuum pressure specs (inches/HG) are in a NA GT between the intake manifold and PCV valve? I've been looking for tubing (-8AN to -10AN) that can withstand the negative pressure and not collapse under vacuum (for an air/oil separator application). I've seen a few posts of various hose collapsing (including SS braided hose). I'm thinking of going with Aeroquip TFE Racing Hose, which is supposed to have a vacuum service limit of 28in/HG pressure. After looking at the price, just want to be sure it can support the vacuum pressure in the 4.6L 3v. Thx.

 

I'm not sure if this helps you or not, but I never see more than 20" vacuum on my boost/vac gauge.

 

I agree with Don. I had a 96 cobra with a Kennebell SCer and boost vacuum gauges. I never saw more then -20 lbs. vacuum.
Scott

 

Don, Scott... thanks for the quick replies. I was curious as to the vacuum pressure as a number of folks have run into hose collapse issues (in NA motors) with some highly rated tubing (GATES LOL Hose, and SS Braided Hose). Kind of surprised me as both were rated fairly high for vacuum applications. Based on their experiences, I figured these 4.6L 3v motors must be creating a pretty stong negative pressure between intake and PCV.