Afm In The Cooler Piping

[RB SANDY]

hey guys my mate has an r33 s2, he wants to put his afm in the cooler piping. would i be able to get some feedback? is it safe? does it affect the computer?

if i can get some replies that would be great

much appriciated

[abu]

Can be done, no real beneficial reason to do it unless you want to make the car dose/flutter pretty loud.

I believe you get a few stalling issues when the AFM is in the cooler piping due to the air flow readings being altered.

Not 100% sure so wont get into detail, someone else will get into that.

What was the reason behind putting it into the cooler piping?

Edited September 4, 2007 by abu

[RB SANDY]

Can be done, no real beneficial reason to do it unless you want to make the car dose/flutter pretty loud.

I believe you get a few stalling issues when the AFM is in the cooler piping due to the air flow readings being altered.

Not 100% sure so wont get into detail, someone else will get into that.

What was the reason behind putting it into the cooler piping?

he just wants to do it to get a bit of a longer and louder flutter/dose pretty much. but thanks for your information mate

[BAMR33]

The afm was not designed to be fitted in a pressurised environment, besides that I don't know why you would want to... Some people supposedly do it to stop stalling after they block off/fit atmo bov or they want to fit a gulping big 6" intake pipe thats not needed.

[abu]

he just wants to do it to get a bit of a longer and louder flutter/dose pretty much. but thanks for your information mate

No worries.

Personally think its worth it for the dose, but some would disagree, if not most!..

Edited September 4, 2007 by abu

[linedup33]

doing that reduces lag a little i dont know how exactly but it does...just get a good tune too to keep everything safe..and of course it gives the flutter.

[abu]

doing that reduces lag a little i dont know how exactly but it does...just get a good tune too to keep everything safe..and of course it gives the flutter.

Reduces lag!?

Are you sure man?

I dont see how it would, there wouldn't be any reason why it would..

Edited September 4, 2007 by abu

[ahh 33 s2]

glad this thread came up as i am wanting to do the dame not for the flutter so much as to clean up the bay a bit more and as bam said i want to put on a big 6" intake

[Mr Jollwah]

It improves throttle response by reducing the amount of air between the afm and inlet valve. I'll try to explain how this works.

AFM only measure air flowing past its sensor wire, now all of the air between the afm and the inlet valves has been premeasured. The engine must use this air before the afm sends the signal to the ecu to adjust load points that the ecu used to calculate fuel and timing requirements.

So say you're driving along at part throttle then u floor it there is some time that passes before the afm measures the change in airflow.

does it make much difference, probably bugger all.

Oh yeah if i was going to do this i'd put the afm post cooler and i'd look at getting a afm body machined from alloy.

cheers

[Hijacker...]

Pretty sure that's acceleration enrichement dude.... and yes it can be tuned for better response

[The Mafia]

he just wants to do it to get a bit of a longer and louder flutter/dose pretty much. but thanks for your information mate

bam said i want to put on a big 6" intake

rofl x 2

doing all that just for a bit of dose...or whatever the f**k it is

[Aif]

i read in a mag that this gets done to fix PFC disease(rare idle issue), they also said that doing it should not affect your tune as it is still measuring air flow past a wire (weather its pre or post turbo its still the same airflowing through it). thats wat i gathered from the article.

Aif

[abu]

rofl x 2

doing all that just for a bit of dose...or whatever the f**k it is

Hahah its not that much trouble man, its like a 15 minute job.

[mad082]

It improves throttle response by reducing the amount of air between the afm and inlet valve. I'll try to explain how this works.

AFM only measure air flowing past its sensor wire, now all of the air between the afm and the inlet valves has been premeasured. The engine must use this air before the afm sends the signal to the ecu to adjust load points that the ecu used to calculate fuel and timing requirements.

So say you're driving along at part throttle then u floor it there is some time that passes before the afm measures the change in airflow.

that isn't quite right. the ecu also works off tps so it will know when the throttle is being opened and will put in some enrichment to compensate.

also you have the fact that the afm will cop a heap of oil if your turbo seal blows or you have blow by issues and would need to be cleaned every few days.

[joeyjoejoejuniorshabadoo]

so skyline's are the new VL turb's now?

[mad082]

yeah they have been the new commodore for a while now. all the new skylines i see in town are driven by bogans. makes me glad i got rid of mine.

[teazn_r33]

i done this only for the reason this to my car was to eliminate the 4 inch inlet of the turbo being reduced to like 2 1/2" from the afm so i put it on the pressure side of the piping so i can have 4 inh all the way to the turbo inlet

f*#k the dose i try my hardest to get rid of it if you want a dose get a vl

muzza'z lol

[taynewguy]

I wish all you dosing (fully sick) skyline owners would sell up and go back to Homodores.

Sick of all this bullshit modification for the sake of a stupid sound which impresses very few people anyway!

Save your time and money on actually modifying for a performance gain perhaps.......aahhh whatever each to their own.

Flame away my dosing freinds.

[WazR32GTSt]

i htink this idea is flawless at best without an ECU tune of some sort to compensate for the new AFM location

my understanding of hte AFM is this..

the AFM works by calculating. it does not directly measure airflow.

it has a wire that hangs into the lumen of the pipe. this wire heats up to a certain temperature that correlates with a certain resistance in the AFM (contains a variable resistor). when ambient air flows over that wire, it cools the wire down. the more air that flows over the wire, the more it cools the wire down. thus, as airflow increases the wire cools down more and the resistance in the AFM changes. this correlates with a change in voltage to the ECU.

this way, the ECU knows approximately what the airflow is based on the hot wire's operation.

now i see 2 major flaws with placing the AFM in the cooler piping

1) the air is compressed. there is absolutely no evicence that i've ever seen that says that compressed air will cool the wire at the same rate as air at atmospheric pressure. let's look at it from the particle model. say i have 100 particles of O2 in a fixed space and it cools the hot wire by 0.1degC. well if this is compressed to 1bar i now have 200 particles in that fixed space. who's to say that this compressed air will cool the wire by 0.2degC? i don't think the relationship will be as linear as you might think.

2) the air is hot. that's right, its after the turbo. that means that the air going over the wire could be up to 50-80degC having just come out of hte turbo. i don't think hot air will be able to extract heat from the wire as would ambient air, and if it does then it wouldn't be at the same rate as ambient air that passes over the AFM normally.

--> but, i believe that both these issues could be compensated for by a good tuner

so, in summary... my understanding is:

1) the AFM works on a hot wire principal

2) placing it after the AFM means that it measures compressed air not normal air, thus it will not measure effectively without a re-tune

3) placing it after the AFM means that it measures hotter air rather than ambient air, thus it will not measure effectively without a re-tune

this is only based on my understanding of how the AFM works and my understanding of basic physics/chemistry. it might help or it might not, but i thought i would throw it in for discussion

cheers,

Warren

[WazR32GTSt]

oh, and btw, what the hell is "dose"?