DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Stupid VTA question

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Old 08-29-2007, 09:29 PM
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Ok im new at this and my kit is on the way. Im running a MAF for now and the parts that are coming has a BOV. How do I recirc the BOV? Please give me the nnon shortened retard answer haha. Thanks
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Old 08-29-2007, 10:06 PM
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The BOV will have a port that the blown off air will exit from. This air is already metered but not entering the engine anymore. You need to install a fitting into the intake tract after the MAF. Then connect a hose so that the air is recirculated after it has been metered.

Something like that. I VTA personally but I run a MAP system.
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Old 08-30-2007, 12:34 AM
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why cant I just relocate the MAF after the intercooler right before my throttle body. So that even after the leaked air, it is still accurate?
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Old 08-30-2007, 12:49 AM
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Originally Posted by piratetim
why cant I just relocate the MAF after the intercooler right before my throttle body. So that even after the leaked air, it is still accurate?
I don't believe that the MAF is calibrated to deal with the amount of flow that you will get if you place it after the turbo. Remember that you are now forcing much more air than the engine was ever capable of doing in stock form.
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Old 08-30-2007, 12:55 AM
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More info about your kit, it will make it easier for us to tell you what you should expect.
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Old 08-30-2007, 11:16 AM
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16g turbo, custom manifold, IC, powercard temporary controller, stock injectors(for now), turboxs RFL BOV, tial WG.
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Old 08-30-2007, 12:41 PM
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Originally Posted by jasonrobo02
I don't believe that the MAF is calibrated to deal with the amount of flow that you will get if you place it after the turbo. Remember that you are now forcing much more air than the engine was ever capable of doing in stock form.
The MAF is still reading the same amount of air, it obviously has to come through the intake before it goes into the engine.

You cannot place the MAF after the turbo because MAF's are not capable of reading pressurized air.

Has nothing to do with calibration or the amount of air.
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Old 08-30-2007, 12:46 PM
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Originally Posted by Saml01
More info about your kit, it will make it easier for us to tell you what you should expect.
He gave enough information, who cares what kind of turbo kit he is running for the purpose of his question.

1. He is running a MAF system.
2. He wants to run VTA.

To the orginal poster, you CAN run a VTA system on a MAF, but it isn't recommened as you will be running rich everytime the BOV "blows off." The BOV must also stay closed at idle.

You would be better off switching to a MAP based system.
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Old 08-30-2007, 12:47 PM
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Originally Posted by piratetim
why cant I just relocate the MAF after the intercooler right before my throttle body.
If you have a 1.6, then the AFM works under the assumption that the air moving through it is at atmospheric pressure, as measured by the barometric sensor built into the ECU. Increasing the pressure increases the mass of air per unit volume.

1.8's with the heated-wire MAF do not use an external barometric compensation as far as I know, so it just might work. Let us know how it turns out. Only thing I can think of is that very rapid temperature swings might upset it.
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