Thread: ve intake pipe question.

we all know the factory rubber intake hose from the throttle body to the maf is not very long (maybe 6-8 inches), but is there a too long (or to short) distance for an aftermarket setup? not talking total intake length including the maf, just the distance between the t/b and maf.

thanks guys.

distance for mine is 14 inches between the tb and maf. after the maf is another 4 inches before it hits the stack and filter.

i noticed a gain when going from a short tube to a longer one.

To answer you question, no not really. The MAF meter is just a measuring tool. I look at the MAF meter as an "open-source" measuring tool that should not affect air flow or resonant frequency, regardless of distance from the T/B or manifold. Changing the the distance of the T/B or intake pipe length, in relation to the valve/combustion chamber will have great affect, as we know. Think about it this way, the sensor only measures the mass flow rate of the air entering the engine. It has no idea how far it is from the combustion chamber, valves or throttle-body. The only thing that should affect power, in relation to the MAF meter is the volume of air that can pass through it at any given time, i.e the size of it. If there is a negative restriction or change in volume or flow dynamics, in relation to the piping before or after it, this will affect the way in which the sensor reads the incoming air or the volume of the air the engine receives in comparison to the flow rate of air that the MAF saw. Of course, the second factor is corrected and influenced by the narrowband O2 sensor. If there are sharp bends right before or anywhere after the sensor, this will also change the flow dynamics of the air. This is the reason that people usually try and have a "straight shot" from the MAF to the intake manifold and certainly for the entire length of the intake tube as well. Avoiding turbulent air before the MAF sensor also allows it to more accurately read the incoming air charge. Regardless of any of these factors, laminar air flow is always important and best in this instance.

Now, I suppose the distance of the MAF is all relative to the distance of the air intake tube/piping itself. If you had a 10' intake pipe and your MAF was 7' from your manifold, this would change the power output and delivery of the engine. The reason for the change though, is the total length of the intake and has everything to do with changing the tuned length of the pipe which will affect resonance frequencies and pulses.

All of this is just theory of course because nobody tunes specifically for changes in MAF distance that don't directly correlate to changes in total intake pipe length or diameter. :]

One final thought, the distance of the MAF sensor to the end of the intake pipe/filter does change power output in some small or possibly large way, depending on the factors involved. The time that the air has to straighten out and become more laminar before entering the MAF meter is certainly relevant to the way in which the sensor reads the incoming air charge. This is the reason why flow stacks/trumphets often increase performance. As far as how much the variation can be, I am not sure if anybody has quantified that through the entire scope of possible change for any given engine or intake set-up. At the end of the day we just know that smooth, laminar air flow is ideal for getting as much air into an engine as quickly as possible.