so if a z32 maf is good for 500hp, how much is a q45 maf good for?

 

Q45 maf is good for Nissan tech.

 

+1...nice!!

 

less.

 

^how so... Q45 is 15mm bigger and should flow/read up to 700 hp..?

 

i don't beleive physical size is what dictates overall hp rating, i think it has to do with how much the sensor can vary in resistance.


Hot wire sensor (MAF)

A hot wire mass airflow sensor determines the mass of air flowing into the engine’s air intake system. The theory of operation of the hot wire mass airflow sensor is similar to that of the hot wire anemometer (which determines air velocity). The General Motors division (GM) was the first car company to use the hot wire sensor.[citation needed] This is achieved by heating a wire with an electric current that is suspended in the engine’s air stream, like a toaster wire. The wire's electrical resistance increases as the wire’s temperature increases, which limits electrical current flowing through the circuit. When air flows past the wire, the wire cools, decreasing its resistance, which in turn allows more current to flow through the circuit. As more current flows, the wire’s temperature increases until the resistance reaches equilibrium again. The amount of current required to maintain the wire’s temperature is directly proportional to the mass of air flowing past the wire. The integrated electronic circuit converts the measurement of current into a voltage signal which is sent to the ECU.

If air density increases due to pressure increase or temperature drop, but the air volume remains constant, the denser air will remove more heat from the wire indicating a higher mass airflow. Unlike the vane meter's paddle sensing element, the hot wire responds directly to air density. This sensor's capabilities are well suited to support the gasoline combustion process which fundamentally responds to air mass, not air volume. (See stoichiometry.)

Some of the benefits of a hot-wire MAF compared to the older style vane meter are:

* responds very quickly to changes in air flow
* low airflow restriction
* smaller overall package
* less sensitive to mounting location and orientation
* no moving parts improve its durability
* less expensive
* separate temperature and pressure sensors are not required (to determine air mass)

 

^that being said, a small inline four has a smaller size maf because less air is flowing through compared to a v6 z32, correct? The more air that the engine consumes generally means the engine should be at a higher hp... Like when you boost a small sr20, you grab a bigger maf, because more air flows... If you can support the horsepower, the q45 should be better, if not... You will lose low end torque because it's too big? I'm wondering.... I'm not to keen on the subject, that's why I asked epstein.. He could deff justify his answers

 

MAFS size does not dictate HP. You pick one that will read more than the amount of hp (volume/mass of air) that your setup will make. If you're making 300whp, then pick one that will max out higher than that.

Size is only loosely connected to hp rating. An 80mm Z32 MAFS will read up to 500whp. But the N60 Maxima MAFS is the exact same size and only reads to 350whp. S13SR and S14KA have the same diameter but the S13SR one gets really narrow in the middle... the S13SR supports about 70hp more.

If you need a bigger mafs than a z32, you're looking at a Cobra mafs or some other late-model american car. It's also possible to get mafs elements put into different sized (larger) tubes and then flowed.

 

Thanks for clarifying, i thought the cobra maf was good for like 400,Z maf was for around 500, q45 was around 600, and a lightning maf was good for like 750.

 

The cobra stuff is probably going to be the only choice for "other late model american" , GM stuff went to frequency based instead of voltage back in 1994, when they went MAF+MAP, 93's were MAP only.