Where Is Everyones Airflow Meters?

[Andrewtler]

I have looked under the hood of a few reasonably powered r33 gtsts and most of them have no airflow meters (that I can see) am I planning my upgrade wrong? I have a z32 and power fc.

[Zaver]

this is because they must running ecus like a link or a vipec which doesnt need an afm and uses a map sensor , which i think is installed near the throttle body

for the power fc u require an afm and the z32 is a good choice

[The Mafia]

lol this made me giggle.

Exactly what the poster above said - They have removed them.

[89CAL]

MAP sensor is placed off a vac line from the inktake manifold.

Z32 AFM will do the job fine

[Guilt-Toy]

i sold it.

[SimonR32]

You can put it inline on the "Cold" side of your cooler piping...

[Dose Pipe Sutututu]

Where it should be, at the factory position, turbo inlet.

You'll notice most of the "enthusiasts" (I used that word loosely as most of them don't have a brain) on boostomgcruising will extend their AFM cabling and hook up their AFM on the cold side of their FMIC, totally acceptable provided you retune your aftermarket ECU's injection map as the air is denser, which many if not all never do. I'll leave the rest up to your imagination on why that would do such an exercise on their VL turbos.

[rad100]

mine is tuned and running with it in the cold sid eof cooler pipe. doesnt stall, miss a beat or anything. and it looks neater on turbo side with a 4inch mouth on my gt30

[paulr33]

those who "deem" 4 inch inlet as necessary, what size is intercooler pipework?

[SimonR32]

those who "deem" 4 inch inlet as necessary, what size is intercooler pipework?

What pressure is your cooler piping under?

[islade]

Kinda related... Getting a 3076 external gate next week, how can i maximise spool noise? I'm using a PowerFC and z32 AFM. at the moment with my current turbo, i have 2.5" intake piping and a mushroom pod, sounds good but i'd love it louder if possible

[wasnt me]

A 4inch inlet on a GT30 is only there because its a surge slotted housing....

The actual intake of the turbo would be around 3inches.

So i cant see how a 3 inch Z32 air flow meter would be a restriction....

[paulr33]

well in front of the compressor is sea level pressure, and after compressor outlet is boost + sea level pressure, known as psia

yeah i can see how the anti surge slots need a wide snout, but 4" just sounds so big, specifally if you are running 3" std piping after the compressor

[islade]

So a 4-2.5" reducer sitting on the comporessor intake wouldn't be considered a restriction?

[paulr33]

if the pipework after it is 2.5" then its basically the same?

[islade]

I didn't know if it was different due to after turbo being pressurised and pre-turbo being under vacuum

[SimonR32]

well in front of the compressor is sea level pressure, and after compressor outlet is boost + sea level pressure, known as psia

yeah i can see how the anti surge slots need a wide snout, but 4" just sounds so big, specifally if you are running 3" std piping after the compressor

It would actually be under vacuum in front of the compressor and pressure after the outlet...

My point being PV=nRT... So if the pressure increases the volume can decrease to flow the same amount of air

Thus you should technically have a larger inlet than cooler piping!

Edited January 17, 2011 by SimonR32

[JonnoHR31]

So a 4-2.5" reducer sitting on the comporessor intake wouldn't be considered a restriction?

depending what size bend you can get you can either put a 4"-3" (2.5" is too small) reducer straight on the turbo and then a 3" pipe to the afm (leave it before the turbo, its not a restriction) or you can run a 4" pipe to the afm and then have a reducer joiner the afm to the pipe (this is what i've done and it works well).

[89CAL]

3" intake pipe

3" cooler pipes

3" exhaust

Ive got a trend going

[jarrod83]

map sensor for the win, the afm pissed me off to no end.

the volume will decrease proportionally provided the temperature doesnt increase, but yeh generally the air is alot denser on the intercooler side, so it makes sense that the inlet side would need a bigger sized pipe to flow the same amount of air, also considering the pressure differential is probably alot smaller on the intake side as well.

Always sounds good in theory but probably only makes a bees dick of difference, although it makes it easier to run a larger air filter which probably helps as well.