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4x4le · 01-31-2009, 01:04 AM

I dont think that the location you chose on the filter would create much suction. I could be wrong there, but I do think a small amount of piping from the maf to the filter would be a better location with the an fitting then welded to the piping.

With either setup (before the maf or after the maf) you have to decide which air you want to be un metered. At idle your going to be breathing in un metered air through the pcv. That might not creat much of a problem as the o2 sensor is going to get the air fuel ratio proper. Under boost with that setup your blow by air is going to be metered. My take on that is though is the air that comes from your crank case probably dont have much oxygen in it though, so I dont want to waste maf voltage on air that isnt going to be benefiting my engine. I also think that the tune will tend to change as the amount of blow by you do get increases with either the weather, or the wear on the engine, or the boost lever your running changes, you will then be creating higher maf voltages for air that has little to no oxygen in it. Air that does nothing for your engine besides create pressure.
In my eyes as a tuner I would rather have the air routed after the maf because you will be reading 100% metered air during open pcv operation and the extra air that has little to no oxygen to be found in it will not be metered (which I see as a plus).

Now like you said, if the car runs right 1 way and not the other then by all means do it the way your doing it. In my case though I have the ability to tune my car whenever I please and I see that air as something I dont want metered. I think that if you meter the blow by air that your car is going to need to be retuned more often as it will cause you to start running richer and cause you to pull more timing as your compression rings start to wear causing your engine to gradually become less powerfull sooner without a retune.

Thats just me. I wont hassle you about it because I think yall are great for coming up with this crancase vent solution and Im so freaking ready to see what you do to the baffiling!!!!

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01-31-2009, 01:04 AM	#10
4x4le Zilvia FREAK! Join Date: Nov 2008 Location: Manchester, Tn Posts: 1,253 Trader Rating: (1) Feedback Score: 1 reviews	I dont think that the location you chose on the filter would create much suction. I could be wrong there, but I do think a small amount of piping from the maf to the filter would be a better location with the an fitting then welded to the piping. With either setup (before the maf or after the maf) you have to decide which air you want to be un metered. At idle your going to be breathing in un metered air through the pcv. That might not creat much of a problem as the o2 sensor is going to get the air fuel ratio proper. Under boost with that setup your blow by air is going to be metered. My take on that is though is the air that comes from your crank case probably dont have much oxygen in it though, so I dont want to waste maf voltage on air that isnt going to be benefiting my engine. I also think that the tune will tend to change as the amount of blow by you do get increases with either the weather, or the wear on the engine, or the boost lever your running changes, you will then be creating higher maf voltages for air that has little to no oxygen in it. Air that does nothing for your engine besides create pressure. In my eyes as a tuner I would rather have the air routed after the maf because you will be reading 100% metered air during open pcv operation and the extra air that has little to no oxygen to be found in it will not be metered (which I see as a plus). Now like you said, if the car runs right 1 way and not the other then by all means do it the way your doing it. In my case though I have the ability to tune my car whenever I please and I see that air as something I dont want metered. I think that if you meter the blow by air that your car is going to need to be retuned more often as it will cause you to start running richer and cause you to pull more timing as your compression rings start to wear causing your engine to gradually become less powerfull sooner without a retune. Thats just me. I wont hassle you about it because I think yall are great for coming up with this crancase vent solution and Im so freaking ready to see what you do to the baffiling!!!!