R34 Airflow Meter

[mad34]

what does the r34 std afm max out at?

[R31Nismoid]

200-220 rwkw usually Chris

[mad34]

hmmm.

well i just had my emanage fitted. and the tuner said that the airflow meter is maxed out at 180rwkw at 12psi??

i know my brother using the exactly the same afm on his r33 was pulling around that 200-220rwkw mark with pfc.

the tuner said that i will need z32 afm as mine is maxing out at the moment at 5volts?? he is saying that the ecu is not liking any more than that?

its got me F**ked i wonder why. I need some expert answers ;P??????????????????????????????????

could the greddy emanage be running a different current to the afm than the pfc?

[R31Nismoid]

Dynos probably. If its reading a tad low then that would explain it.

Auto or Manual? If its auto then a manual would be 10rwkw or there abouts higher.

[mad34]

its an auto.

but what about not being able to boost any higher than 12psi with std afm??

has anyone else boosted their r34 past 12psi with std afm?

[Bass Junky]

I've still got my stock one on at 250 rwkw

Racepace tune though....

[mad34]

you have pfc dont you bass?

i just got off the phone with tuner now. he pulled 182.5rwkw at 12psi

i have just made my car more powerful and i am already thinking about the next stage.

I have a sickness. Skyline Fever

[Bass Junky]

Yep I do

I've got a feeling some 'bending' of the voltage curve was done, but my car is quite happy with the stock AFM.

I thought I'd have to buy a Z32, but lo and behold, it's all good.

[mad34]

bending isnt breaking so i say the more bent and still working the better!

well i think i will be high flowing my turbo asap

[Bass Junky]

it's worth it!!!!

Power_v_Torque.pdf

[R31Nismoid]

technically you dont "need" to change.

[RB30-POWER]

Why not consider the extra map sensor plugin harness for the emanage.

It will read boost pressure off the map sensor once the afm maxes out.

Just a thought.

Edited December 15, 2005 by RB30-POWER

[mad34]

Why not consider the extra map sensor plugin harness for the emanage.

It will read boost pressure off the map sensor once the afm maxes out.

Just a thought.

<{POST_SNAPBACK}>

yeah i was looking at that on mohd parts. thankyou most helpful. i wasnt 100% sure what it did.

[Sydneykid]

Why not consider the extra map sensor plugin harness for the emanage.

It will read boost pressure off the map sensor once the afm maxes out.

Just a thought.

<{POST_SNAPBACK}>

How does that help?

The boost controller should be ensuring that the boost stays constant, especially at the sort of rpm the AFM is going to be maxing out at. So the MAP sensor shouldn't see any differences in the pressure. That means there is no variation in the load signal to cause the load mapping reference to move. So all you get is RPM mapping reference changes, which is what you would get with a maxed out AFM anyway.

The only time you really need an AFM upgrade is when unanticipateable changes in airflow occur, ie; not linear with rpm changes. At high rpm (ie; past boost build and camshaft timing effects) this shouldn't be an issue. The fuel and ignition requirements are satisfactorily driven off the rpm change.

That's why I don't change the AFM's until it is necessary because of tuning requirements, and reaching 5.1 volts at 6,000 rpm in an RB25DET is not one of those. It would seem that RacePace have a similar philosophy.

cheers

[Bass Junky]

SK.

Yep, my voltage only hits 5.115v for about 1000 rpm at about 6000rpm, and then backs off into load line 19.

no requirement for change.

How's that Air Guide?????

[RB30-POWER]

How does that help?

The boost controller should be ensuring that the boost stays constant, especially at the sort of rpm the AFM is going to be maxing out at.  So the MAP sensor shouldn't see any differences in the pressure.  That means there is no variation in the load signal to cause the load mapping reference to move.  So all you get is RPM mapping reference changes, which is what you would get with a maxed out AFM anyway.

cheers

<{POST_SNAPBACK}>

Yeah your right.

But with regards to the original question, i was under the impression he wanted to run more boost then what he had, which would require someway of the ecu knowing that the extra boost is being run.

[Sydneykid]

Yeah your right.

But with regards to the original question, i was under the impression he wanted to run more boost then what he had, which would require someway of the ecu knowing that the extra boost is being run.

<{POST_SNAPBACK}>

It's not the amount of boost, but the change in boost that the ECU would need to make use of for mapping purposes. MAP sensors are usefull when boost is building or decaying. But when the pressure stays the same for periods of RPM change they are not much use at all. You still have to use the RPM axis to determin the fuel mapping.

cheers

[Cubes]

Just a heads up for those that don't know.

Coventry and the likes sell new Bosch Z32 AFM's for ~$280.

Edited December 16, 2005 by Cubes

[Busky2k]

My friend's R34 pulls roughly 215rwkw and hits 5.1V on his PowerFC.

[CNBLOW]

hey mad34, my AFM was maxing out at 13psi only in cold weather though, mines an auto a well