New intake set up

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Jul 21, 2015 | 10:12 AM

#31

Sylvan

Lead Lap

iTrader: (6)

Joined: Sep 2014

Posts: 601

Likes: 4

From: Alberta

Quote:

Originally Posted by Meanstreak

This is not ISF specific but does represent our stock system in principle. Hopefully it will help convey what I am trying to say. Follow the air path and you will see how PCV airflow does end up in the combustion chambers. If you unhook the tubing from the intake (prior to the TB) the system will now pull (unmetered) air from outside and it will end up in the combustion chamber.

I am not saying that the system won't work this way at all. The fuel system will adjust to the unmetered air as long as it stays within the 15% trim window and everyone will be happy. If it goes beyond the 15% trim adjustment you will get a lean code.

Thank you for the picture, If you follow the air once you cap the intake tubes (upper intake in the picture) NO AIR that has not been metered is entering the intake(only air that goes into the intake make it to the combustion chambers) , the air from the cam covers is actually going into the crank case not the combustion chambers. So the two valve covers now just vent to atmosphere and have no vacuum but it will still vent the crank case in most cases guys drill out the PVC when venting to atmosphere.

it is also common to put a catch can/oil air separator between the PCV and the intake vacuum port so you would still have vac to help evacuate the crank case but the can keeps the oil fumes from entering the intake and reducing the effective octane as well as keeping oil residue from gumming things up.

Last edited by Sylvan; Jul 21, 2015 at 10:20 AM.

Jul 21, 2015 | 10:58 AM

#32

Meanstreak

Pole Position

Joined: Sep 2012

Posts: 244

Likes: 5

From: Greenville, SC

Quote:

Originally Posted by Sylvan

once you cap the intake tubes (upper intake in the picture) NO AIR that has not been metered is entering the intake(only air that goes into the intake make it to the combustion chambers)

You are correct IF you cap the vacuum intake port at the PCV valve which I do not think is the case with the RR system. This would completely eliminate the PCV function also. Perhaps Rafi could clarify this?