Wurf

Guys,
I just spoke with a tech at Pro-M about the frequent MAF failures on modified Maximas. He was somewhat aware of the problem and offered the following.

If I send them my stock MAF and air filter box assembly off my 2002 SE, they will use it to calibrate a larger 80mm MAF unit that will NOT fail like the stock unit. The larger 80mm size will offer less restriction to the motor than the stock unit.

After this happens, they can offer this larger, high flow 80mm meter in combination with a special, Pro-M designed filter that does not use any oil ( similar to Apex-i ) for sale to maxima.org members for $250.00

The filter is a bolt-on design using a flange built into the meter.

I would like to get some feedback from forum members regarding this idea before venturing into this.

Please feel free to post replies or email me.

PoLo

iTrader: (7)

well from what i've seen int he past, there are many claims to many different technolgies and seldom seem to work. it would be great. i guess to further intrigue us, i'd like to ask, how do they plan on "calibrating" these units. what R&D have they come up with. are they sure they can do this. i guess more details. whether i'd rop 250, that's another story. i guess if more information was involved, it would lead more to swaying interest. but good luck.

Quicksilver

iTrader: (1)

It sounds appealing to me. I have been considering playing with other aftermarket MAF's in an effort to adapt them for use in my VQ35 anyway...

PoLo

iTrader: (7)

quick, do you know if aftermarket maf's are a known thing in the auto industry. i thought equipment like this was oem specific, so having a company release an aftermarket maf would be vehicle specific and not that profitable. i could very much be wrong. any existing companies that have succeeded with aftermarket maf's, that showed improvements over stock?

Quicksilver

iTrader: (1)

Check into the 5.0L and 4.6L mustang world of aftermarket MAFs...

I'm sure I could adapt one with the proper amount of time and effort, but those are two things I can't provide right now.


http://www.modulardepot.com/index.ph...d4e1c133ed5edb

Rafe

Hey Quicksilver, when i had my 86 turbo Z , we used the 89-90 Mustang GT MAF s, it worked like a charm then and i don't see why it wouldn't work now. Next time i am in the junk yard i will pull a 2001 and up Mustang MAF and try it.

Jay93SE

Pro-M is a very well respected company that specializes in MAF's. They are very well known in the Mustang world. I have yet to hear of a MAF failure from Pro-M, Granatelli, or any of the other large aftermarket MAF companies. Come to think of it I don't think I've heard of a stock Ford MAF ever failing, either.

Wurf

Answers to questions:

These guys will use my MAF and measure it's output with their equipment to create a map for the new unit. Do they know how to do this?... I'd say without a doubt, they know what they are doing. Pro-M has to be the premier aftermarket MAF company in this country.

They sell MAF units for many other vehicles, including Nissans. They currently do not have anything for the VQ35 in the 2002 Maxima.

http://pro-flow.com/


I have questions for you guys.

1. What does it typically cost to replace the factory MAF in the Maxima?
2. What fails in the MAF unit specifically, and why?

Jeff92se

iTrader: (82)

Probably have to do some porting work on your intake manifold and use some type of 80mm throttle body.

ABS

I would recommend using a brand new Nissan MAF so you know that it is operating at normal/standard spec. How can you be certain your own MAF is 100% ok?

Wurf

The MAF simply outputs a voltage signal based on airflow. As long as it's in range, the computer uses it along with the other sensors to determine fuel flow and timing. My car runs great, starts great, and idles great. If it were out of range, it would run like crap. It has to be VERY accurate and working perfectly for the car to run right.

I'll be the guinea pig anyway, and if it doesn't work, I'll let you guys know.

I have some questions regarding the sensor they plan to use in the MAF the tech proposed. I'll let you guys know that information as well.

I also would like to know why he is proposing an 80mm meter. That's an enormous meter for a 3.5 liter motor, and I think a 75 would be more than adequate. If the cost is the same, I guess it won't matter, but suffice to say, the website shows a 75mm meter supports up to 600hp. The 2003 and newer Mustang Cobra uses an 80mm meter. We don't need that much airflow obviously.

I'll keep you guys posted and we'll see if this is a viable alternative to buying three or four MAF meters to cover yourself from frequent failures. At the same time, maybe it can add some performance with the high flow filter and higher flowing meter.

DAVEB

iTrader: (133)

I tried this- the Mustang MAF is WAY different.

ABS

Is the 350z MAF the same or does it have a larger bore?

E55AMG2

iTrader: (4)

350Z MAF has a different harness, therefore wont fit. Also, my AM600 meter has been used with 5 different kinds of intakes (inc stock) and oil has never been a problem. Also, the additional airflow into the engine at the intake (before the manifold) is not the problem. If someone were smart, theyd be working on improving the intake manifold and exhaust flow, which are where the problem areas in the VQ exist.

MAXINXS

I'd be curious to know the price of just the maf sensor, not an intake to go with it. This is assuming they could get one to work for our cars.

E55AMG2

iTrader: (4)

Nissan charges about $400 for the tube and sensor. But, were I to speculate, id say about $100 - $150 for the MAF itself.

FrankTheBunny

I'd be interested as long as it was designed to fit any intake system... it sounds as though they're considering designing it to work with their own custom intake - too many people have spent $$ on intakes to scrap them for a new MAF.

Wurf

E55AMG2 - I am completely on the same page with you. How about having the TB pipe and the intakes extrude honed? Anybody done that yet?

The factory meter never seemed too small to me. At least I've never seen any data showing it was a restriction. I'm almost certain it's not. If a stock 302 Mustang motor can get by with a 60mm stock MAF meter, and only needs a 70mm meter for a performance package ( Ford Racing ), then I would conclude the 3.5L Nissan engine should have plenty of airflow with a 70mm meter. That's the size I understand these motors come with anyway. I have not measured my meter yet. PLEASE correct me if I'm wrong. The pics I've seen of the sensor assembly look rediculous compared to the GM and Ford parts though. That huge chunk of plastic hanging down inside is taking up a lot of airflow robbing space.

The oil and MAF sensor....think of all the MAF equipped cars running oiled cotton filters without problems. Perhaps the oil free Pro-M filter is snake oil ( pardon the pun), but hey...Apexi seems to do well selling theirs based on a similar concept. The Apexi looks like a better filter to me though.

My idea was to find a way to put a bullet proof, aftermarket MAF in front of the VQ35 motor. They want to package it with filter that bolts on to the front of it. That's just the way the meter is designed and flow calibrated - with the filter installed.

The filter itself is not expensive if bought seperately.

Maybe I'll see if there's a savings going with something like a 75mm Bullet housing or similar.

I will continue to persue this and let you guys know.

Thanks guys

Wurf

Is there any way to remove this from my sig without posting many more threads?
Define important please....anyone.

"I need to read the FAQ and IMPORTANT threads before posting a question"

E55AMG2

iTrader: (4)

The AM600 (the meter in the 2003 maximas) is almost bulletproof. Especially with a long tube intake. The things that make them blow are the shorty intakes, and PR intakes where ppl havent reused the stock flex hose to connect the tube to the TB. Basically, it was designed to run with a certain length tube.

However, there are exceptions. I did run a frankencar shorty with a K&N and had no problem (except the lack of low end and retarded timing from underhood heat).

Wurf

Why do the shorty style intake systems destroy the MAF? Is it due to vibration from the intake noise resonance destroying the filiments like I suspect?


Has anyone taken a dead MAF, one that died after installing a shorty style intake, and determined exactly what broke on it and why?

I'd really like to know what's going on with these things.

studman

Be sure that when they design the new MAF, that they also map out and include the "air intake temperature sensor". It's the little resistor-looking-like thing on the side of the MAF. It's only present on the 2002-2003 MAFs, as 2000-2001 has it located up by the stock scoop.

EDIT: And for what it's worth, Hitachi makes our MAF. Their auto-parts web-site is http://www.hap.com/. In talking to the guys over there, they do not sell directly to the public, and they don't make a stronger version of the MAF than what we already have. If you want to try, you are more than welcome, but you may not get far.

studman

The stock MAF is a thin, film-style MAF that incorporates a real thin piece of film, similar to photographic film. As wind enters the MAF assembly and flows into the film, the film's temperature drops. The ECU compensates for this drop by adding more voltage (in order to keep the film at a certain temperature). The ECU then measures this added voltage and uses it to determine the overall airflow.

After learning all of this, it has proven my theory that the MAF isn't faulty. The ECU's original programming (pre-TSB) had an upper limit on the amount of voltage that was sent to the MAF's film. However, the voltage was higher than the breaking point of the film, so the MAF would basically overheat and break.

When the TSB was released, Nissan got a new MAF design, along with new data on the voltages. When the new MAF is installed under the TSB, the ECU receives a programming update that corrects the upper voltage limit.

So in a sense, the new MAF and ECU update [b]should have[b] fixed the blown MAF issues. For most people, this is the case, as they have not had any problems since then.

But there is a flaw. The MAFs (new and old) are still a film-style design. If the wind passing through the film is stronger than the film itself, the film breaks, regardless of the temperature.

Now, for the theory part....

Shorty intakes allow for alot of air to be introduced to the intake. By locating the MAF near the induction point, the air flows from all points, as if it were rammed into the MAF. This wind, hitting the film from all angles, could cause the film to break, regardless of temperature.

Also, with the shorty intakes, the air introduced into the intake is warmer than even stock air. This reduces the change in temperature in the MAF, thereby ruling out the failure being caused by too much voltage from the ECU.

Now, for the CAI, it's basically the opposite story. The air is well flowing and "organized" by the time it reaches the MAF. So the MAF failure isn't normally caused by excess wind breaking the film.

However, the air being introduced is much cooler than stock. This lowers the temperature of the MAF, thereby causing the ECU to increase voltage to keep it at the pre-set temperature. With the increased voltage, especially at higher RPMs (more air induced), the MAF may reach the breaking point due to voltage.

So depending on which intake you have, you can see that you still run the risk of breaking the MAF.

And as if that weren't enough to boil your brains, when the failure occurs, the same thing breaks. It doesn't matter which intake you use, the film still gets broken. And I haven't found a way to determine whether it broke due to voltage or due to wind.

E55AMG2

iTrader: (4)

Took the words right out of my mouth

kcowden

iTrader: (2)

I looked into this last year and was quoted around $500 to get the manifold extrude honed. I haven't heard of anyone doing this yet.

Wurf

Studman,
Thanks for the rundown on the MAF failure process. I'm going to take this information to the tech at Pro-M and see what he thinks. Perhaps there is an alternative sensor out there with the same plug and pinout configuration. I have no idea at this point.

If he planned on using the stock sensor and simply sticking it into a different housing, I'm going to pass on the idea.

Based on your info, it would appear the safest intake system is an Injen, or possibly a Place Racing / Cattman unit with plenty of tubing ahead of the meter.

It would be cool if somebody came up with a way to reinforce the factory film sensor or repair it.

Extrude hone is $500.00 - too expensive for me. You could have somebody cut it if necessary, hand port and polish, and weld it back together for less than that.

HNDA ETR

iTrader: (10)

bump for updates...

P. Samson

If I remember the theory of the "hot wire" resistor type MAF sensor correctly the wire or film gets a constant voltage (usually battery voltage) supplied to it then varies its output voltage back to the ECU depending on the cooling affect (amount of air and its density) of the intake air flowing by it. The hottest the wire or film will get will be with IGN. ON and the engine not running and I quess a high underhood temp. may influence it as well. ie. (no airflow and highest resistance and lowest output voltage) At idle with minimum airflow there is some cooling affect, somewhat lower resistance and a little more output voltage progressing up to the highest & most dense airflow (WOT, Max RPM) resulting in the wire or film being cooled to the max, resistance is lowest and the output voltage is therefore the greatest. I agree the MAF failures are probably aggravated by the wire or film being hot and therefore weaker. (like a lightbulb filament with voltage applied) But this is at IGN. On, ENGINE off, and then more importantly at idle. Think about it. You sit there at idle then go WOT in a fraction of a second. This is where we see some MAF failures. It is at its weakest, then we hammer it with max. airflow. I believe it is also aggravated by using hot engine compartment air for the intake air (less cooling affect.....plus the loss of performance aspect) and short type inlet ducts/tubes that cause the air to "buffet" the sensor. Also the infamous screen should be left in place. It is just a fact of life that these MAF sensors require a nice smooth airflow to work properly.

wild willy

iTrader: (10)

I am sure this applies to your vq too..Click the red X on engine and read

http://autos.msn.com/research/vip/re...=ratings&tab=4