AFM in Cooler Piping?

[Z2TT]

Hello,

1. From what I have heard, when you add an intercooler on, the air charge gets much denser and therefore it is better to put your AFM between the intercooler and the Intake manifold so it measures compressed air and would improve response and acceleration and give better A/F ratio's as opposed to running with the AFM in stock position. This sounds logical to me.

2. Other people say when you add an intercooler its neccessary to get an aftermarket ecu or piggy back and get it tuned.

What do you people think about 1. The AFM in IC Piping and 2. That it is important to get an aftermarket ecu and tune when installing an IC?

Thanks,
Z2TT

[Duk]

Hello,

1. From what I have heard, when you add an intercooler on, the air charge gets much denser and therefore it is better to put your AFM between the intercooler and the Intake manifold so it measures compressed air and would improve response and acceleration and give better A/F ratio's as opposed to running with the AFM in stock position. This sounds logical to me.

2. Other people say when you add an intercooler its neccessary to get an aftermarket ecu or piggy back and get it tuned.

What do you people think about 1. The AFM in IC Piping and 2. That it is important to get an aftermarket ecu and tune when installing an IC?

Thanks,
Z2TT

Airflow meter's measure mass air flow, either directly (hot wire type) or via calculation (vane/flap type plus the inlet air temp. sensor or those stupid kahman vortex things that mitsubishi use). Any air that the turbo/supercharger pumps has to come thru the AFM and so (in theory) the location of the AFM wouldn't make any real difference in response to airflow change.

However, most AFM's do have their temp. sensor, or their inbuilt temp. compensation (hot wire type) as part of the airflow meter housing and so if you add an intercooler or fitted a better 1, then the ECU doesn't know that the air going into the engine is actually cooler than it would be in standard form.

Where I see a bennefit in AFM in the intercooler piping is when the AFM becomes (or already is: 4AGZE's ) a flow restriction. That is, the airflow capacity of the AFM will increase with air from the turbo/SC being pushed thru it.
The ECU would also be reading actual inlet air temps after the intercooler, but that may or may not be a good thing, depending on the way it's set up from the factory.

[oldcorollas]

agreed, intake air may not have much effect on mixture, but it should have a strong effect on timing.. and if the result is a godo thing depends on if there is a seperate temp senser in intake, or how the ECU if programmed.

usually you should not need to worry about tuning after IC, since the engine should be relatively safely tuned to cope with a wide variation of post turbo temps.. cooler air should make it less prone to detonation anyway?

i say fit the IC, then dyno it and check AFR and for pinging (if possible) and then worry about aftermarket ECU

[gianttomato]

It will certainly help with 'dosing'. All the VLT boys do it.

[Xistant]

It will certainly help with 'dosing'. All the VLT boys do it.

beat me to it.


thats how you get your "dose"age hahaahaah

[Z2TT]

My Soarer with 1g-gte allready has an Intercooler fitted, came when I bought the car.

And yes all the VL Turbo boys like to relocate their AFM, isnt that so they have room to put a metal pipe on the mouth of the turbo? I like VL Turbo's and was after one originally before I got into soarers, and used to read the Calais Turbo forums a lot, many of the users were saying that they get much better response and power by putting their AFM's in their cooler piping.

So I dont know if I should worry about it or not.

[Mos]

This subject has been covered in the previous threads.
Hot wire AFM signal outputs are proportional to the density, so the dosing/metering works after the cooler on the VLs.
Flapper style AFM signal outputs are proportional to the square root of the density so this WILL NOT work with a flapper AFM.

Mos.

[Duk]

I've seen blow thru flap AFM. Couldn't tell u how it drove tho

[Mos]

We've all seen things that shouldn't be done

[Z2TT]

So the AFM would be fine in stock position even with an intercooler and higher boost?
I'm fine with it as long as it doenst crap out, just wondering since the VL boys all do it.

[Mos]

Stock position = uncompressed air.

Hot wire AFM you can put it in compressed air (because it meters the extra density) but flapper you cannot put in compressed air (because it meters the square root of the extra density).

If you're replacing the factory cooler with a larger cooler, in theory, you should not in any way increase the maximum amount of air the system can handle, so the effect on the AFM should be inconsequential. Plenty of people install larger coolers.
In you increase boost at the same time, then you're increasing the potential maximum and in theory it could reach the maximum that the AFM can meter.

BTW, you haven't told us what engine and car - not good to assume

Mos.

[Z2TT]

My Soarer with 1g-gte allready has an Intercooler fitted, came when I bought the car.

So I dont know if I should worry about it or not.

Yeah like I said engines a 1g-gte, its a gen 3.

Mods -

Front mount intercooler
2.5" cat back exhuast
Blits BOV (doesnt seem to be releasing air)