HFM question????HELP!!!

[FATHER]

Hi guys i have a dude, if posible to change our hfm(air flow meter) for a 6cyl. one like m3 or 325, i think is the same sensor with a bigger housing. Help please

Take a look from Cali's gallery

http://www.318ti.org/gallery/showpho...o=1961&cat=609

[Midnight Autoworks]

Yes, use the larger hfm, it works but you must use larger injectors and software to calibrate the fuel curve to the new signal of the hfm

[FATHER]

Hellowwwwww, any help to me???I need to now if i can change it, only the Flow Meter with a bigger one, or other option is to modified the oem housing with a bigger one ???Is only an ideato take more flow, bacause my intake is 3inch but inthe flow meter 2.5 i like to have 3 inch enterely intake

[DustenT]

Originally Posted by FATHER

Hellowwwwww, any help to me???I need to now if i can change it, only the Flow Meter with a bigger one, or other option is to modified the oem housing with a bigger one ???Is only an ideato take more flow, bacause my intake is 3inch but inthe flow meter 2.5 i like to have 3 inch enterely intake

FATHER - I've answered this question for you several times already. You need custom ECU programming or a piggyback to control a larger HFM. You'll also need to increase the size of the injectors at the same time. I recommend getting NickG's software, stage 3 comes with a 3" HFM and larger injector. You CAN'T simply hook up a larger HFM without programming, it won't work and you'll probably damage your car.

[FATHER]

Originally Posted by DustenT

FATHER - I've answered this question for you several times already. You need custom ECU programming or a piggyback to control a larger HFM. You'll also need to increase the size of the injectors at the same time. I recommend getting NickG's software, stage 3 comes with a 3" HFM and larger injector. You CAN'T simply hook up a larger HFM without programming, it won't work and you'll probably damage your car.

I know my friend and i'm looking for the NickG's software but my question is because my friend Milton have a 1993 325 and his talk to me about a upgrade to m5 flow meter, but is not to change the sensor y change the hausin to a bigger one.If you look the link you sew two screw that atach the sensor to the housin,Our idea is change the 325 housin(3.0) by a m5(3.5) and the m44(2.5) by the 325 (3.0). But we neede to be sure because the two engines have forced induction. I know many guy that do that in japanese engines but need to be sure... remember i not try to change the sensor... only tha 0.5 bigger housin.Thanks for help , without your help guys, may be i need to use my skate to go work...

[DustenT]

Originally Posted by FATHER

I know my friend and i'm looking for the NickG's software but my question is because my friend Milton have a 1993 325 and his talk to me about a upgrade to m5 flow meter, but is not to change the sensor y change the hausin to a bigger one.If you look the link you sew two screw that atach the sensor to the housin,Our idea is change the 325 housin(3.0) by a m5(3.5) and the m44(2.5) by the 325 (3.0). But we neede to be sure because the two engines have forced induction. I know many guy that do that in japanese engines but need to be sure... remember i not try to change the sensor... only tha 0.5 bigger housin.Thanks for help , without your help guys, may be i need to use my skate to go work...

Each sensor is calibrated to measure air flow for the specific housing. Say the HFM reads 2V at 2500rpms with the 2.5" housing, lets pretend that equals 20 cu in of air (completely made up number). Now, if you put the 2.5 sensor in a 3.0 housing, it will still read 2V at 2500rpms, but because the housing is larger it will actually be sucking in 25 cu in of air, not 20 cu in. The ECU uses the HFM Voltage to adjust the fuel and ignition curve. By switching the housings, you will be supplying more air to the engine without telling the ECU about it. This will create a lean condition (very bad). I hope this makes sense.

[Dredder]

Originally Posted by DustenT

Each sensor is calibrated to measure air flow for the specific housing. Say the HFM reads 2V at 2500rpms with the 2.5" housing, lets pretend that equals 20 cu in of air (completely made up number). Now, if you put the 2.5 sensor in a 3.0 housing, it will still read 2V at 2500rpms, but because the housing is larger it will actually be sucking in 25 cu in of air, not 20 cu in. The ECU uses the HFM Voltage to adjust the fuel and ignition curve. By switching the housings, you will be supplying more air to the engine without telling the ECU about it. This will create a lean condition (very bad). I hope this makes sense.

Give me a image of the stock bin and I'll find all your fuel/timing map location

[DustenT]

Originally Posted by Dredder

Give me a image of the stock bin and I'll find all your fuel/timing map location

Are you doing DME tuning for OBD2, or just locating maps? What kind of interface is needed to connect to the DME?

[FATHER]

Originally Posted by DustenT

Each sensor is calibrated to measure air flow for the specific housing. Say the HFM reads 2V at 2500rpms with the 2.5" housing, lets pretend that equals 20 cu in of air (completely made up number). Now, if you put the 2.5 sensor in a 3.0 housing, it will still read 2V at 2500rpms, but because the housing is larger it will actually be sucking in 25 cu in of air, not 20 cu in. The ECU uses the HFM Voltage to adjust the fuel and ignition curve. By switching the housings, you will be supplying more air to the engine without telling the ECU about it. This will create a lean condition (very bad). I hope this makes sense.

Yes my friend, that make sense, now i call my friend to tell him about it, and the damage to him motor, thaks i think now is a bad idea

[Dredder]

Originally Posted by DustinT

Are you doing DME tuning for OBD2, or just locating maps? What kind of interface is needed to connect to the DME?

Im only tuning obd1 for now. Search my threads on BFC. I've posted an afr reading

[DustenT]

Originally Posted by Dredder

Im only tuning obd1 for now. Search my threads on BFC. I've posted an afr reading

Let me know when you can tune obd2.