will the apexi power fc eliminate the maf?

[leesredgt]

i was wondering does the power fc eliminate the amf if not what kind of standalone can i get that will eliminate the maf b/c i want to run a top mount manifold and turbo.

[uber95]

Plenty to read at the followinghttp://paulr33.skylinesaustral...q.htm

[bumblebtuna]

^^ #38

[leesredgt]

ok so if it needs a maf to function if i understand it correctly so what standalone can be tuned w/o a maf?also to what is a megasquirt

[uber95]

http://www.google.com/search?h...earch

http://en.wikipedia.org/wiki/Engine_Control_Unit

Need to spend about a good day reading before you even start to think you need a standalone.

[Darius]

Why do you want to replace the MAF? What kind of power levels are you shooting for? You should have gotten an RB26 if you wanted to run MAP.

[StricNyne]

D JETRO uses map sensor but idk if its avail for rb25.... you could always use a haltech or ems or someother standalone... i will admit my next proj will use megasquirt tho..

[leesredgt]

is not that i want to eliminate the maf but i guess i dont under stand how can i hook a maf to it if i have a top mount manifold?heres a pic of what im talking about. i want mine to be like member eh?s car.hpefully he wont get mad if i put a pic of his car up.

[craz4240]

Power fc d-jetro utilizes map sensor.......however if you just built a custom intake tube and possibly lengthened the wires you could run a maf without any trouble.IMO MAP sucks.

[garage-c]

You can buy a Greddy E-Manage Ultimate & associated MAP sensor. It has the ability to convert your car from MAF to MAP. Check out this post on SAU...

http://www.skylinesaustralia.c....html

[eh?]

I run an aem ems but with a bit of know how and tinkering you can use the d-jetro RB26 pfc.

[leesredgt]

so you just hooked up a laptop and tuned yours to run w/o a MAF? how hard is it to tune with the aem?also this is a little off subject but does it hurt the turbo/engine to run w/o a filter?

[Darius]

he didn't just hook up a laptop and was able to change it to MAP. The RB26 PFC can be used on the RB25 if you do some rewiring and make sure all the sensors are connecting into the ECU in the right places. Plus you have to buy separate MAP sensor(s) that will actually send data to the ECU.

I think what you are going for is a Greddy IM and you're wondering how the MAF sensor works with that. In that case, people typically run the MAF in a blow-thru setup where the MAF is below the battery tray in the cold pipe. You can run a MAF in front of the turbo and get the same result, but the only difference is you won't be able to vent your blow off valve to atmosphere for that supa hawt fnf sound. There are ways to actually run the BOV to atmosphere, but you have to get the settings right or it will run rich and bog when you let off the gas under boost.

[leesredgt]

ok so if i move the maf to under the battery tray it is in the intercooler pipe right?also to if i just move it to the other side on the cold pipe why couldnt i use the power fc for the rb25det or is that what ur saying and im misunderstanding or r u telling me in order to do that i will need the greddy im.thanks again i know im proably complicating it but i want to make sure before i go and buy this stuff.

[ZiG]

also to what is a megasquirt

Hmm, sounds like a name for a bad porno?

[eh?]

so you just hooked up a laptop and tuned yours to run w/o a MAF? how hard is it to tune with the aem?also this is a little off subject but does it hurt the turbo/engine to run w/o a filter?

Basically yes, with the new map and air temp sensors hooked up I can just upload an RB25 MAP sensor "calibration" to the ecu and drive off. The aem supplied map isn't perfect but with a wbo2 it's not an issue. That map is just supposed to get you to a dyno for tuning.

I drive my car only a few times a month so I'm not worried about a not having a filter. But a filter should always be used.

[leesredgt]

ok could i put the maf right after the turbo on the hot pipe like in the picture below and still use a power fc?also will any ordanairy cone filter go on the turbo?

[ZiG]

yes.

yes.

[jsack]

i have the ultamate e-manage and it has the options to elimenate the maf. it has worked great for me so far it is just limited as to how hi of hp you can go, but my tuner said it should hold up to or around 500hp i am running 368hp right now.

[eh?]

yes.

yes.

no

It needs to be between the throttle body and the BOV and be a decent distance between both.

[JPsNissans]

You could always run a blowthrough MAF setup if you are thinking you won't have a place for the MAF or something... That's when you put the MAF after your turbo and intercooler, hence the "blow-through" instead of "draw-through" like the stock setup. I never see any of the RB people talking about this though... That's what everyone does in the world of turbo QR25's... and that's how I want to end up running my setup.

[bmadd2402]

dude, thats what just about every post before yours said.

[jt15833]

its funny that since you didnt want to put maf in now you want a standalone that doesn't need a maf.

[REZAZ32]

I've seen a lot of people running blow through setups on their cars just because either they are too lazy to hook up bigger piping to the intake of the turbo, or they don't want to go to a MAP setup. However, the system is flawed because the stock MAF sensor is made to read from smooth flowing ambient air and it is not pressure sensitive (pressure=Temperature/Volume).

If you run a blow through setup, you're readings from the MAF to the ECU will be off calibration under boost because of the air turbulence and the difference in air pressure that the MAF sensor was never meant to read. The MAF sensor works by monitoring the mass air flow (metered in this case off a hot wire system) from the density of the air coming into the engine, which is not the same as air pressure. As the pressure goes up, the stock MAF sensor is unable to keep up with the huge quantities of air going past it, because the air pressure, and therefore air density, goes higher than the unit was designed to monitor.

More air=more pressure in a constant volume, and the MAF is not a pressure sensor. That's why the MAP sensor (Manifold Absolute Pressure Sensor) is used on some cars, instead of a MAF sensor. It's just a different way of monitoring the same thing. The only difference is one monitors pressure and temperature per RPM, and one monitors mass air flow from air density. The ECU transforms the signal into something usable to run the car.

Think about it. If the MAF sensor can be run on the pressure side, then why wouldn't some manufacturers do that? It would be easier for them to just run it on the intake hot side piping and call it a day. Also, if MAF sensors could be used on the hot side of the intake charge, then what's the point in switching to a MAP setup? Hmm....food for thought before you run your MAF sensor hot side.

This is why the Djetro is different than the regular Power FC. The Djetro is made for use with a MAP sensor, while the regular power FC is made for a MAF setup.

In conclusion, the blow-through MAF sensor will work for low horsepower, low boost applications. However, if you raise the boost and horsepower levels, the MAF sensor will quickly be over it's duty and out of its original design purposes. This means that you will not have a very fast car. Run it if you wish, but think about other options before you go that route.

Hope this helps you make a more well-thought-out decision before you get in too deep.

[Fearsome_tea]

We cut the sensor out of a z32 maf and put after the intercooler. Been doing that for a while. The PFC seems to be common for 25s, and cheaper for the most part. And its not that ppl are lazy. W hen you use the Z32 "blow through" the maf reads th

[rb25drag]

Currently im running the MAF on the filter side of the turbo. Seems to work fine. But im eliminating the MAFS, Knock sensors, TPS, and all that B.S with the Propane setup.

leesredgt- Add up all those prices, from the MAFS to the Stand alone unit just to tune with. There jacking up the prices on all that, Thats just to tune with, Now add all the injectors, fuel rail, throttle body, ETC along with that and your looking into the 3,000$ + range not counting tune. If you got the money thats cool but im not going to work another year to save 3,000 just to get all that crap, Switching over to propane is going to cost me less than 1000$ and the power is limited to my turbo size. There is no maps, MAFS, or anything. Propane is simple and EASY to tune.

I might be coming up with a Cheaper alternative to getting that power. So keep in touch with me, We are starting the propane coversion beginning of march.

[cdorhout]

I've been running blow-thru for some time now, and very successfully. Roughly 400whp right now, and plenty of room to grow yet with my Q45 MAF. I can tell it's not being maxed by watching the voltage of the MAF at full load.

Yes, blow-thru changes the air flow map a little, but it's easily tuned out if you know a little bit about tuning. Hell, the PFC will actually tune itself fairly well on it's initial startup learning mode. You're gonna have to tune the car anyway, so switch to blow-thru now before you tune.

Don't go crazy with buying a bunch of crap, it's not worth it.

[Darius]

I've seen a lot of people running blow through setups on their cars just because either they are too lazy to hook up bigger piping to the intake of the turbo, or they don't want to go to a MAP setup. However, the system is flawed because the stock MAF sensor is made to read from smooth flowing ambient air and it is not pressure sensitive (pressure=Temperature/Volume).

If you run a blow through setup, you're readings from the MAF to the ECU will be off calibration under boost because of the air turbulence and the difference in air pressure that the MAF sensor was never meant to read. The MAF sensor works by monitoring the mass air flow (metered in this case off a hot wire system) from the density of the air coming into the engine, which is not the same as air pressure. As the pressure goes up, the stock MAF sensor is unable to keep up with the huge quantities of air going past it, because the air pressure, and therefore air density, goes higher than the unit was designed to monitor.

More air=more pressure in a constant volume, and the MAF is not a pressure sensor. That's why the MAP sensor (Manifold Absolute Pressure Sensor) is used on some cars, instead of a MAF sensor. It's just a different way of monitoring the same thing. The only difference is one monitors pressure and temperature per RPM, and one monitors mass air flow from air density. The ECU transforms the signal into something usable to run the car.

Think about it. If the MAF sensor can be run on the pressure side, then why wouldn't some manufacturers do that? It would be easier for them to just run it on the intake hot side piping and call it a day. Also, if MAF sensors could be used on the hot side of the intake charge, then what's the point in switching to a MAP setup? Hmm....food for thought before you run your MAF sensor hot side.

This is why the Djetro is different than the regular Power FC. The Djetro is made for use with a MAP sensor, while the regular power FC is made for a MAF setup.

In conclusion, the blow-through MAF sensor will work for low horsepower, low boost applications. However, if you raise the boost and horsepower levels, the MAF sensor will quickly be over it's duty and out of its original design purposes. This means that you will not have a very fast car. Run it if you wish, but think about other options before you go that route.

Hope this helps you make a more well-thought-out decision before you get in too deep.

I am sorry but I don't know where some of this info comes from but it is not how the blow-thru MAF setup functions in the real world.

Whoever said that the "blow thru" setup has never been talked about on NICO...SEARCH...it was as common two years ago as the "how much does it cost to install an RB?" threads are today.

To correct this, the RB25 MAF can be run in a blow-thru installation the same as a draw thru. It still sees the exact same amount of air, the only difference is the blow-thru air is pressurized. Since it is pressurized, air is denser and cools the hot-wire in the MAF sensor directly proportional to the pressure. As a result, the MAF "sees" the temperature drop and can still accurately measure the air that caused it. Pressure has nothing to do with a MAF sensor unless it is too much for the housing to take and it cracks or asplodes. At this point, you just need a standalone ECU and a wideband to tune it.

If you are anal, you can scale the MAF sensor on a flow bench to make sure the voltage it is putting out is matching what the ECU thinks it is getting. There is a table in the PFC where custom MAF sensor voltages can be added for varying air flow.

As far as maxing out a MAF sensor, it solely depends on what air flow rate the MAF corresponds to 5V. If that air flow rate is enough to feed your hp goals, perfect. If not, there are bigger MAFs out there from Ford manufacturers (SCT is one, but they're jackoffs if you tell them you are putting their MAF in a Nissan. The e-mail response to my question was "We don't support Nissan." <end>). The Ford Lightning MAF is another option, but I haven't looked completely into it. I think there are two different MAFs that they used and the second generation can support more hp.

[Carl H]

Like darius said this post is flawed in some of its points...

I've seen a lot of people running blow through setups on their cars just because either they are too lazy to hook up bigger piping to the intake of the turbo, or they don't want to go to a MAP setup. However, the system is flawed because the stock MAF sensor is made to read from smooth flowing ambient air and it is not pressure sensitive (pressure=Temperature/Volume).

This is hardly the case, I'm certianly not lazy and in reality I had no room for a drawthur setup on my car.If you think in a drawthru setup the incoming air is a smooth airflow then you're wrong again...why do you think they have grating over the maf? to help CREATE turbulance to ensure equal distrobution thru the maf for correct readings; dont want deadspots in the maf that would defeat the purpose.

Quote »If you run a blow through setup, you're readings from the MAF to the ECU will be off calibration under boost because of the air turbulence and the difference in air pressure that the MAF sensor was never meant to read. The MAF sensor works by monitoring the mass air flow (metered in this case off a hot wire system) from the density of the air coming into the engine, which is not the same as air pressure. As the pressure goes up, the stock MAF sensor is unable to keep up with the huge quantities of air going past it, because the air pressure, and therefore air density, goes higher than the unit was designed to monitor.[/quote]You contradicted yourself in this same post segment,maf is mass air flow not a pressure sensor...just like you said so it doesnt care if its under pressure or not it is going to read MASS AIRFLOW.

Quote »More air=more pressure in a constant volume, and the MAF is not a pressure sensor. That's why the MAP sensor (Manifold Absolute Pressure Sensor) is used on some cars, instead of a MAF sensor. It's just a different way of monitoring the same thing. The only difference is one monitors pressure and temperature per RPM, and one monitors mass air flow from air density. The ECU transforms the signal into something usable to run the car.[/quote]PV=nRt, does not apply to real life which is why it is the IDEAL gas law which assumes STP which almost NEVER occurs in reality unless you create those conditions.

Quote »Think about it. If the MAF sensor can be run on the pressure side, then why wouldn't some manufacturers do that? It would be easier for them to just run it on the intake hot side piping and call it a day. Also, if MAF sensors could be used on the hot side of the intake charge, then what's the point in switching to a MAP setup? Hmm....food for thought before you run your MAF sensor hot side.[/quote]PVC systems would foul the maf sensor...also the hotside after the intercooler is not only at a higher tempature but less dense, that would create an inaccurate reading hence why the maf is put on the coldside where the charge is brought down to +/- 10* ambient...better than your engine bay.

Quote »This is why the Djetro is different than the regular Power FC. The Djetro is made for use with a MAP sensor, while the regular power FC is made for a MAF setup.

In conclusion, the blow-through MAF sensor will work for low horsepower, low boost applications. However, if you raise the boost and horsepower levels, the MAF sensor will quickly be over it's duty and out of its original design purposes. This means that you will not have a very fast car. Run it if you wish, but think about other options before you go that route.

Hope this helps you make a more well-thought-out decision before you get in too deep. [/quote]Then why was I able to make ~387rwhp at 18psi and only register 4.63v out of my 5.12v on a z32maf...even at 22psi it was only 4.75v and that maf is known to read AT LEAST 500hp worth of air.

[l0nestar]

p00nd!