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Custom Afm

Dj laBBy

By Dj laBBy,
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Dj laBBy

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Hey anyone made a custom AFM??

Am thinking of using a Q45 (90mm 3.5") internals and plumbing it into a 4"pipe.

The reason you might say, to slow the air speed through the meter which will give a greater scope. Undoubtly 4" is not much of an increase, but i can also bolt it straight to the 4" turbo inlet and use a 4" filter. I was maxed out at 20psi (260rwkw) so maybe this may help a little.

Plus it is custom and i like tinkering. hehehe

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Dj laBBy Collaborator

Dj laBBy

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your telling me you maxed out a q45 afm at 20psi and only made 260rwkw that doesnt sound right.. more info please

Ah good question.

Had low comp pistons and rb25 head, =extra low comp setup. It was somwhere around the low 7's cr.

When you think about it, 20psi is great for an AFM on rb30 setup, but it was the comp that was killing me, saying that it was an ignition monster, just wanted more and more. Could've thrown 30psi in there and it would've been happy.

However i have high comp standard rb30 pistons in there now so comp is a little more respectful, though would love to make over 300rwkw. So we just see.

Mate its a good experiment just to see how it all goes. plus "Custom" love custom!!!

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djr81 Grand Master

djr81

Posted
Posted
Hey anyone made a custom AFM??

Am thinking of using a Q45 (90mm 3.5") internals and plumbing it into a 4"pipe.

The reason you might say, to slow the air speed through the meter which will give a greater scope. Undoubtly 4" is not much of an increase, but i can also bolt it straight to the 4" turbo inlet and use a 4" filter. I was maxed out at 20psi (260rwkw) so maybe this may help a little.

Plus it is custom and i like tinkering. hehehe

My understanding is that if you change the internal diameter of the pipe in which the air flow meter resides you change the calibration of the meter.

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Craved Grand Master

Craved

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My understanding is that if you change the internal diameter of the pipe in which the air flow meter resides you change the calibration of the meter.

thats more than likely trua and something that has already been discussed in the Forced induction section.

the modifictaion to the AFM would require you to create a boxed section one the side of the inlet pipe and im assuming that it would require it to be on a straight section too to ensure the flow is even through the meter.

be some fiddly work to get the mounting threads welded on to keep the unit flat inside your box.

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Dj laBBy Collaborator

Dj laBBy

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Yah calibrated, true, but basically whats the difference in calibration when you tune the car for the new calibration?? Yah am running a Power FC, so its all good. The only time you'd be worried about "calibration" so to speak is when you are using the standard comp.

Basically this way you are kinda tricking (real lamens terms) the computer there is less air going through the AFM, the just adjust the mixtures to suit, not rocket science.

Yah tricky making a box?? well really all you need to do is to get a bit of pipe, machine or file a basic flat, make a base plate, weld that on, then by cutting some ally plate say 20mmhigh x what ever the standard width is, then just weld it all up. Screw the AFM unit in and just silicon on a top if you can't be bothered tapping and screwing the top.

Piece of piss(if your a welder/fabricator)

Was thinking of it last night in bed for about an hour. Should hopefully have started it and maybe some pics by monday.

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Craved Grand Master

Craved

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Yah calibrated, true, but basically whats the difference in calibration when you tune the car for the new calibration?? Yah am running a Power FC, so its all good. The only time you'd be worried about "calibration" so to speak is when you are using the standard comp.

Basically this way you are kinda tricking (real lamens terms) the computer there is less air going through the AFM, the just adjust the mixtures to suit, not rocket science.

Yah tricky making a box?? well really all you need to do is to get a bit of pipe, machine or file a basic flat, make a base plate, weld that on, then by cutting some ally plate say 20mmhigh x what ever the standard width is, then just weld it all up. Screw the AFM unit in and just silicon on a top if you can't be bothered tapping and screwing the top.

Piece of piss(if your a welder/fabricator)

Was thinking of it last night in bed for about an hour. Should hopefully have started it and maybe some pics by monday.

only reason if that would be tricky is if the underside of the circuit board isnt flat

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  • 2 months later...
Medium Dave Proficient

Medium Dave

Posted
Posted
Yah calibrated, true, but basically whats the difference in calibration when you tune the car for the new calibration?? Yah am running a Power FC, so its all good. The only time you'd be worried about "calibration" so to speak is when you are using the standard comp.

Basically this way you are kinda tricking (real lamens terms) the computer there is less air going through the AFM, the just adjust the mixtures to suit, not rocket science.

Yah tricky making a box?? well really all you need to do is to get a bit of pipe, machine or file a basic flat, make a base plate, weld that on, then by cutting some ally plate say 20mmhigh x what ever the standard width is, then just weld it all up. Screw the AFM unit in and just silicon on a top if you can't be bothered tapping and screwing the top.

Piece of piss(if your a welder/fabricator)

Was thinking of it last night in bed for about an hour. Should hopefully have started it and maybe some pics by monday.

Might be a bit of science in it, the afm reads the airflow and outputs in a logarithmic curve, then the computer outputs that in a linear curve using a conversion table, by increasing the diameter you may throw the curve well out of whack. How's it all going anyway? im curious to know

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  • 3 weeks later...
Craved Grand Master

Craved

Posted
Posted

Hi, I don't know much about air flow meters but i need one for my 95 series 2 gtst skyline.

Can anyone advise me on what one to get and where to get it from?

Cheers.

You will get a better response in the Forced Induction section.

stick with STD or if you have a Power FC and are chasing power try a Z32..

Search in FI if you are unsure about this

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