Hey, you gota give him what he wants. But he’s only hurting his efforts to get anywhere 500+ with an FMIC.
5 reasons not to put an FMIC on a Z. Z32 class is in session:
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If he wants to see anything around 500 he needs a dual intake. A single MAF won’t be able to handle it. What are his options for a dual intake with an FMIC? Slim to none. There are a few, but they relocate the filters to horrible locations (like the now vacant SMIC spots) where they’re exposed to everything. I’m sure once he figures that out, he’ll be back for a Hybrid custom dual intake setup… Have fun custom fabing that Nissan lovers
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FMICs just kinda sit there… there isn’t any ducting that directs the air through the core. With SMICs, not only does the air flow much easier through the core in the stock location, but you can use the stock ducting or buy aftermarket ducting to further improve airflow. Also on this note, if you look at the factory design of the guards under the car, they create a low-pressure zone behind the core - so the air is first directed through the core by the duct then literally “pulled” and accelerated out though the back. With an FMIC the air goes… no where.
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The next most obvious of problems is cooling. Not only is the perfect intake location now blocked, but so is the radiator. Yeah it’s not totally blocked, but enough where you’re going to see problems (dyno and street proven.)
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Yet another problem is that FMIC cores are very long. The longer the core, the more pressuredrop you will experience as compared to a core of the same height and width. Given that most SMICs have appreciably more height in the core (most also have more width) and significantly less length to them, you are going to see very notable advantages when it comes to pressuredrop - the SMIC cores will beat the long narrow FMICs all day long in a comparison of inlet vs. outlet pressures.
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Now to the big problem - look at the design of it. The driver’s side throttlebody feeds the passenger bank of cylinders. This means that the driver’s turbo is driven by the driver’s bank of cylinders, but, the driver’s compressor feeds the passenger bank of cylinders.
This is done to create a balancing effect. As an example: If the driver’s wastegate actuator has more preload than the passenger turbo, it will be more inclined to produce a little more boost pressure than the passenger turbo. However, since the driver’s turbo feeds air into the passenger bank of cylinders, that additional pressure is going to make that side of the engine produce a little more power, which in turn, will cause the passenger turbo to spin a little harder and provide additional airflow to the driver’s bank of cylinders, thereby balancing the power output of the two banks.
A FMIC “crossflows”, meaning, the air flows through the intercooler from one side of the vehicle to the other, entering the opposing throttlebody, and returning into the cylinders on the original side. Now like I said, he’s going to need a dual intake setup and given that the passenger side of cylinders is operating completely independently of the driver’s bank, this is where the big problem comes into play. If the driver’s turbo is generating a little more boost than the passenger side, the ECU is doubling the airflow value for the driver’s bank, which is going to cause an overfueling issue for the engine as a whole since the passenger side isn’t flowing quite as much air. On the flip side, if the passenger side is flowing more air, it is going to cause the system to run lean as a whole… then kaboom.