Afm Pulse

[Devils_Advocate21]

There seems to be a bit of discusion on afm pulse vs intake length, in regards to idle hunt rough idle and the likes, I would like to open a discussion on, the best intake length to overcome or to minimize the issues that are related to afm pulse being the afm too close to the inlet of the turbo. Recommendations of peoples experiences in this case as well, what is the best length from turbo inlet to the afm in regards to custom intake pipes.

As this may be a very common problem that i have seen and or experienced lately. All comments welcome

Cheers A

[Adriano]

have you considered putting the afm in the intercooler pipe near the throttle body?This would prevent idle and blowoff problems due to backspin and venting bov's

[Devils_Advocate21]

Interesting? Pics would be good to see inline results? i was assuming that the afm would most likely have to be locate before turbo? Must be wrong :S

[Devils_Advocate21]

Any more ideas, comments, suggestions all welcome people

[Medium Dave]

Call me crazy, but does'nt the afm also measure the air temp? and so putting it in post turbo could affect tuning - I dont know, just a thought.

[GunMetalR33]

Call me crazy, but does'nt the afm also measure the air temp? and so putting it in post turbo could affect tuning - I dont know, just a thought.

AFM's basically inform the ECU of the amount of charge required to keep the hot wire at a certain temp. Thus more air running over the hot wire = more charge to keep the stable temp.

Therefore if the air is pressurised & heated it may well effect the AFM's readings.

It all comes down to the cooling properties of pressuries air verses un-pressurised air.

Not sure if any of that makes sense

Sorry, getting off topic here...

[Sydneykid]

There seems to be a bit of discusion on afm pulse vs intake length, in regards to idle hunt rough idle and the likes, I would like to open a discussion on, the best intake length to overcome or to minimize the issues that are related to afm pulse being the afm too close to the inlet of the turbo. Recommendations of peoples experiences in this case as well, what is the best length from turbo inlet to the afm in regards to custom intake pipes.

As this may be a very common problem that i have seen and or experienced lately. All comments welcome

Cheers A

I take it you are looking for discussion on poor idle (and return to idle) due to airflow reversion back though the AFM from the compressor of a large turbocharger. If that’s the case, then it has been covered many times. For a detail discussion try a search on “reversion” and perhaps “EIDS” which is the HKS electronic circuit for overcoming such problems.

In simple terms, use the largest inlet pipework you can, put as much distance between the compressor inlet and the AFM as possible. If all else fails grab an EIDS or relocate the AFM to the pipework on the compressor outlet, before or after the intercooler. Then retune the engine with those items in place.

cheers

[Devils_Advocate21]

Thanks sydney

[GeeTR]

Call me crazy, but does'nt the afm also measure the air temp? and so putting it in post turbo could affect tuning - I dont know, just a thought.

Your crazy!

Jokes

Bout the temp thing. I too initially thought it would be an issue, though the stock setup does fine on both a 40 degree day / 3 degree day. Although i haven't yet taken steps to stick the AFM in the IC piping, i would rather that way, then trying to make distance between AFM and turbo mouth.

[rob82]

In designing the SP MX5 (Limited Run Turbo MX5) for Mazda Australia my boss used two 90 degree bends to stop reversion back through the AFM.

[R31 POWER]

Would that restrict flow tho? I to suffer from short pipe work causing probs so im keen to try anything really