Thread: Using a breather with an intercooler

I am aware of the possible issues with running a VC breather and the vacuum leaks. I have experienced this myself on some previous builds (not on GTPs though)...

I am wondering if some of you have used a breather instead of modifying your setup with Full Stack Intercoolers? If so, what did you do to the tune (or anything else) to help combat the vacuum leak symptoms? Any other adverse effects?

I am under the impression that the vacuum leaks really only affect the car during idle and sub-boost conditions. Under boost, the vacuum leak should essentially go away as the crankcase is under positive pressure right? so the issues would likely go away completely under boost..

Open to thoughts and suggestions

yeah, except you spend very little of your time in boost, and a vst majority of time in vac conditions...with a pcm that adjusts fueling while at low TPS% (ie vac) for both low rpm and high rpm AFR.

so really its not good, just delte pcv system and run the filter and change your oil far more often, or keep the pcv system and plub in a fresh air supply from behind the maf, but in front of the throttle blade, and you will no longer have any tuning issues.

ive run the breather, its a pita, 10 minutes of work and for less than the cost of a breather you can retain oem type pcv operation.

Originally Posted by Turbocharged400sbc

yeah, except you spend very little of your time in boost, and a vst majority of time in vac conditions...with a pcm that adjusts fueling while at low TPS% (ie vac) for both low rpm and high rpm AFR.

so really its not good, just delte pcv system and run the filter and change your oil far more often, or keep the pcv system and plub in a fresh air supply from behind the maf, but in front of the throttle blade, and you will no longer have any tuning issues.

ive run the breather, its a pita, 10 minutes of work and for less than the cost of a breather you can retain oem type pcv operation.

Good points.. that is what I ended up doing on my vettes in the past.. Running a breather, having vacuum issues, then building a custom PCV/catch can setup and it worked the best. No vacuum issues and clean air going back into the intake track. Maybe I will deleted the manifold PCV setup and make a catch can setup going from the oil cap up to the intake (pre-TB, post-MAF as you mentioned).

http://www.grandprixforums.net/threa...7-99-gtp/page7 anthony did this pcv mod to his lim.

Originally Posted by 97AutoXVette

Good points.. that is what I ended up doing on my vettes in the past.. Running a breather, having vacuum issues, then building a custom PCV/catch can setup and it worked the best. No vacuum issues and clean air going back into the intake track. Maybe I will deleted the manifold PCV setup and make a catch can setup going from the oil cap up to the intake (pre-TB, post-MAF as you mentioned).

the air/oil separator is great for reducing knock tendency with not oil suspended in the recirculated air.

this is a breather per bank setup i did on the Turbonnie. no pcv function, just oem pcv air paths to allow the oil to fall out of suspension and drain bak to the crankcase and external lines to a breather tank. hopefully he only has to drain and clean the breather tank once a year vs the vc/fill cap point which gives you tons of oil mist (aand is one reason breather cars tend to drip oil from em, enless an 04+ neck is used and its crammed with stainlesss choreboy to allow the oil to condensate on and drain down

Originally Posted by Scottydoggs

http://www.grandprixforums.net/threa...7-99-gtp/page7 anthony did this pcv mod to his lim.

..... How did that guy only dyno 302 whp with cam e85 fsic and all other mods. .

cause not zzp's dyno

My friend dyno'd @ 329 WHP on stock cam, 1.9's FSIC e85 headers and catback on a 2.55 on a gen V... on "not zzp's dyno". But I suppose that dyno could have been off as well