Canceling out pumping losses of throttle governed engines

[greasemonkee]

Tests have revealed that a vacuum on the crankcase is of negligible benefit of an otherwise stock engine.

At 7 in/hg of vacuum the seals were screaming bloody murder while drawing in air.

This thread can be considered null

[Christ]

They do this with vacuum pumps for race cars... yes, vacuum in the block is a good thing, and it actually provides more than "marginally greater" ring seals.

I'm not entirely sure how much vacuum they use, but you can get belt-driven vacuum pumps from Summit Racing and Jegs for the purpose.

[hyperyaris]

It is illegal in the US.

[Christ]

Source?

[hyperyaris]

www.supersixmotorsports.com/pdf/PCVBypass.pdf

What exactly is a catch can and how does it benefit? [Archive] - The Australian 300zx Owners Association

[hyperyaris]

Oops ignore Australian one lol

[Christ]

Try again - that article had to do with bypassing the PCV system. What the OP is talking about involves using the OEM PCV system with a higher vacuum - i.e. still feeding the crankcase vent into the intake system to be properly recirculated and burned.

[hyperyaris]

Ah ok. I thought he was bypassing it. My mistake.

[KJSatz]

Honda's R18 has a system to help with that, right?

[PaleMelanesian]

Pulse and glide solves the problem.