NefMoto

I've got some Tial 605's on the way and am trying to decide which way to go as far as MAF housings are concerned.

I've been thinking about getting the Ford Lightning MAF housing (90mm), or trying to find some other used 85mm housing used on some Stg. 3 applications.

I'm running a stock motor for now and will cap my power around 460awhp and assume I will need approx 25-26psi for that... although I might start to increase boost as TQ start to drop off, so I might end up with close to 30psi by redline.

That said, any suggestions?

i'm interested to see what anyone says about this... i saw on epl's website that a 605 car they tuned was using an 85mm maf housing.  just based of the pics it looks like they use something different for the 770's though.

Well I got one of my ford buddies looking into a 90mm Lightning MAf for me, and yesterday I got a free 4.2L Bosch MAF housing (85mm) from my buddy @ SEM Motorsports.

I have a spare OE Hitachi MAF & housing, so I was thinking of modding the 85mm 4.2L housing to accept the Hitachi MAF (just some plastic welding).

Thoughts?

As for the EPL stuff... It seems Tony's new GT fueling kit is using a completely different MAF sensor element as well, which is supposed to support more flow.  That's what I've gotten from his posts about it anyway.

Every MAF is going to be different, and there are a lot of variables that affect how much power you make with every lb of air that flows through it.  I remember back in the day that a lot of the mustang guys were pegging the 90mm lightning maf at just over 500rwhp.  The transfer function is well documented, and they top out at 62lb/min of air flow.

Since 1lb of air makes between 9.5 and 10.5hp, you can see this maf will peg between 590 and 650 crank horsepower.
 
Keep in mind not all maf housings are created equal either, even if they are the same diameter at the sampling point.

Good info Jason...

So in your opinion, will the 85MM 4.2L MAF flow enough for my goals?

My advice is to use what MAF will work for your current goals, and change it again later when you build the bottom end.  As long as you plan to tune within the limits of the stock rods, I'd say you're probably OK.  As far as above and beyond, I really have no experience there, because at some point I believe you will have no other choice but to underscale the MAF, which will require starting from scratch.

The thing is, you can always change the maf if you peg it.  I am running an ASP 85mm housing with hybrids and fairly aggressive boost and have not pegged the maf, even though my bottom end is on borrowed time.  I think the 85 should be OK for now.

Log every run, and progressively add desired load while tweaking your fueling/ignition based on the logs...  If your MAF is too small you will creep up to the limit this way, and it should be apparent when you hit it.  At that point you can either decide to keep the car within the limits of the MAF, or move up.

The thing is, being previously from the mustang world, I have seen people take the "gonzo" approach, throw a 100mm maf on their car, it runs great at WOT, and then they are irritated when it doesn't idle well, or stalls when declutched at high speed because the air under the hood is turbulent enough to upset the sampling at low engine speeds.

Good stuff, thanks for the insight.

I will probably stick with my free 85mm then and work from there... Even if I have to underscale a bit to reach my desired boost/power levels that would be fine with me.  In any case maybe by the time I am ready to really push my setup (with a built bottom end) we will have more info for a MAF setup like EPL has now.

I believe this is the new MAF that EPL is running:
http://www.promracing.com/mass-air-meters-c-2/pro80-p-5

Interesting. I actually stumbled on that page 2 nights ago when looking for Ford lightening mafs.

I can't believe they are charging $50 for the 30 point transfer function now.

Well... here is my 4.2L 85mm MAF conversion... I did a simple plastic weld just to hold it in place.  I'm going to tweak it so it's as straight/centered as possible and then weld it up, and seal it with epoxy.

Comments/suggestions?

(https://lh6.googleusercontent.com/_51mfYIRRh0Y/TVwZb5cOGkI/AAAAAAAAAHI/FQAP9iWD8wY/s800/2011-02-16%2013.31.12.jpg)
(https://lh3.googleusercontent.com/_51mfYIRRh0Y/TVwZfuhg7LI/AAAAAAAAAHQ/xFP9OZVAkLE/s800/2011-02-16%2013.30.58.jpg)
(https://lh6.googleusercontent.com/_51mfYIRRh0Y/TVwZYBJhYcI/AAAAAAAAAHE/-sXjIY7KAis/s800/2011-02-16%2013.31.36.jpg)
(https://lh4.googleusercontent.com/_51mfYIRRh0Y/TVwZT3yUskI/AAAAAAAAAHA/qtRsAG1b-cg/s800/2011-02-16%2013.32.02.jpg)

You guys should take two cues from the Ford guys:

#1 - extending the metering capacity of the meter at the expense of resolution is fairly trivial.  All the Ford meters (which are hitachi) use a 12V supply, power GND, signal GND, signal.  The signal can and will go over 5v if you push enough air through the meter, but the ECU is limited to 0->VRef on the ADC channels, which is usually 5v.  You can put a voltage divider on the signal line coming out of the meter (ok, it would be better to use an Op-amp, but...) and you greatly increase the maximum air limit of the meter at the expense of resolution.  If you don't feel like getting down and dirty with the electronics, Diablosport make a plug n play product called the MAFiA that has 8 selectable dividers.  You can almost double the metering capacity of a meter with a MAFiA.

#2 The PMAS HPX "slot style" meters just plain rule.  They have an integrated air temp sensor.  They bolt to a flange on a piece of pipe so you can meter as much air as you want by changing the housing size.  I've done several 600+ HP Mustangs with a 102mm (4") housing and a HPX meter.  Plus you can also use a voltage divider / MAFiA if you need to.  Another plus of these meters is that they do BLOW THROUGH MAF like a champ!  The GM variant of these meters (which read in frequency instead of voltage) are actually used as a blow through meter in an OEM application I believe (Saturn Sky / Pontiac Solstice 2.4L turbo)

I will be doing 770s on my car soon and the MAf problem doesn't let me sleep at night (well, not really but almost).

As is, even 90mm Ford Lightning MAF will not be enough to properly meter the air. I would like to stick to old and familiar Hitachi element so maybe 95mm MAF would be sufficient... But I am wondering if I am not getting myself into idling problems with such large housing.

On the other token, it would seem that relatively "small" audi 85mm V8 bosch element maf can read more air (at 5v) than hitachi in 90mm housing so maybe this would be the way to go...

Anyway, should I end up with what seems like most reasonable solution of 90mm housing, would I have to essentially tune with wideband O2 at WOT and adjust maf readings table (forgot the name of table now but you can adjust MAF readings for rpm/load) to hit a sweet spot since my MAF would be out of its reading range. Or above mentioned signal dividers and rescaling of main MAF table is the way to go?

Thanks./

You could just rescale the MAF correction table at high and high air flow. But in doing so your car will become much more sensitive to air temperature and air density, since you have now essentially hard coded the expected air flow when you hit the limit of the MAF.

I realize that and recognize the shortcomings. In my personal opinion the voltage dividers would probably be the way to go if the maf is indeed capable of outputting over 5v signal when it maximum measurable air mass is exceeded.

From the looks of it, your V8 85mm housing should just about be ok for 605 in moderate boost but you will definitely hit the wall at anything over 25psi of boost and more air being pushed into the block.

I am hitting a limit of 85mm EPL housing which tapers from stock air box to 85mm to Rs4 accordion when I am at about 24psi of boost. My MAf logged MAF flow hits the max value and I slowly start getting lean on wideband. I since lowered to 22 psi since I don't want to kill my k04s but I think it would get even worse with better turbos like 605s.

EPL. Since EPL has successfully incorporated the 360deg maf linked above, it sounds like this would be way to go. According to these people, it can reliably measure air up to a vicinity of 800HP which is more than anybody sane would need on 2.7t engine.

All we would need is the maf map for it :). Can we hijack EPL tune to get it? :)

How about you don't do that. I'm sure you'd have no problem coming up with it on your own, right?

You can buy the MAF map from the company that makes the MAF. Or, you can just figure out the MAF map yourself with some testing.

Probably a ProM MAF ...

It is. I posted this link in an earlier post:
http://www.promracing.com/mass-air-meters-c-2/pro80-p-5

Other tuners are using the stock Hitachi sensor with 85 or 90mm housings and making 600+whp... Are they just underscaling the MAF then?

The real problem is that you're running out of values an ECU can read when you approach such WHP figures with 90mm MAF. What happens is that there is so much air going through the MAF that its readings go over 5v....which is the ceiling for ECU. Anything higher than that registers as 5v...regardless if it is 5.5v or 6.0v. The wider tha gap, the more unaccounted for air is in the system causing you to go lean.

To date a way to go around it was to make some dyno runs at WOT and massage correction table for MAF and call it a day.

EPL (finally) approached if from the right end and implemented that POM maf that can read much higher air velocities without losing low end resolution. It still reads 0-5v but when it indicates 5v, the actual flow is much higher than what 90mm with Hitachi elements measures at that voltage...

Does the POM MAF have a non-linear transfer function?

No idea... but almost all mafs are non-linear and in their description/order page they talk about non-linear transfer function so I guess it is a "yes".

Err, i should say, even MORE non linear than stock?

Definitely. I mean it supposedly can measure far more air mass than any other MAF currently available for S4 so in order to accomplish this and still not lose low-end resolution, it needs to compress high end reading into fairly narrow voltage range resulting in much steeper curve.

I am currently in talks with LOBA (european tuner out of germany) who has 100mm MAF in their offerings. It is not the cheapest option by any shot (almost 200 pounds), but seeing that there really is no other option while still preserving Hitachi maf, I might go that route...

I changed directions a bit.

PMAS HPX slot style MAF sensor is de-facto one of the best on market and used all over the scene on high powered cars. It can support up to 750whp on a simple 3" maf and ramping up from there.

I think this will be my new setup:

3" or 3.5" MAF housing with honeycomb screen option:
http://www.treadstoneperformance.com/product.phtml?p=1289&cat_key=467&prodname=MAF+Mass+Air+Flow+Adapter+Pipe%2C+Nissan%2C+FORD+and+GM%2C+Hitachi+Style

Sensor:
http://www.vmptuning.com/store/index.php?p=product&id=193&parent=30

Sensor come with application that will generate necessary maf curve. I am not sure if the curve will be suitable for ME map as it needs 512 values for 0.01-5.12 volt range, but even if it isn't here is the software that will do this for you pretty accurately (the more points you have the better):

http://www.curveexpert.net/

Download evaluation version, import or type in your X,Y points. Hit "Apply Fit", "nth order polynomial", choose between 4th - 6th order (best results) and once you get the graph, right click it and choose generate table. Enter 0.01 for minimu, 5.12 for maximum, 0.01 for increment and output to table... voila. You might have to massage the table near 0.01 voltage but otherwise it is pretty nicely interpolated.

I will report back once I get it all up and running.

This sounds nice, I'm in for results.

Order is in.

PMAS HPS slot sensor
http://www.themustangshop.ca/product/1479798/300713

90mm billet aluminum housing (Draw Through variant)
http://www.themustangshop.ca/product/1479825/

6-pin connector pig tail:
http://www.themustangshop.ca/product/1479921/

Why not use just use the MAF on one of the turbos and double the transfer function values?

That's a bad idea, b/c no one turbo works with the same efficiency, that's for one - so one would pull more air than he other as it is almost impossible to set wastegates exactly the same.

But the real problem is with plumbing in our cars. you'd have to redo the PCV system to not return blow-by gases to accordion/Y-pipe anymore as you'd be metering this air now if you had the MAF on one of the turbos. This assumes it was still on "sucking" side of plumbing.

Re-doin the current set up with a MAF th can actually meter more air is the way to go as proven over and over.

What setup will you be testing this on?  I'm pretty sure i've seen you in the b5 s4 section on AZ. 
supports over 1000hp + software for to give you a maf curve for <$300
now i'm holding my breath until you post results.  This looks like a very doable solution for big power applications.  i can put this in when i do frankenturbos, and if i ever want to go big,i can with the same maf setup.

This will be going onto Tial 770 setup, 2.8 heads and ferrea valvetrain which I plan to allow to rev to 8.5k or so.

I reviewed HPX flow sheet and it looks damn amazing. Here is their excel with flows for certain voltages for 3" maf (75-76mm):

http://vmptuning.com/forum/attachment.php?s=ff442afa4165911c9ba34af2c769b586&attachmentid=55&d=1218290959

Interestingly, it seems to have pretty good resolution down low. It is very similar at idle to my 85mm housing with OEM hitachi sensor.

On the other hand, it hits almost 2700 l/h at maximum reading on 75mm maf which means it essentially measures almost 2x as more flow than 85mm housing with our OEM hitachi sensor can read...

IF you were wondering why I didn't go with Pro-m MAf.... it is simple. They don't really offer universal MAF element that has consistent characteristics.  They really cater to Ford OEM crowd and all their MAFs are custom calibrated to pretend to be OEM MAF. For what reason I don't understand but vague ads like "adds 9HP to your stock engine" seem to paint the picture. Every MAF of theirs comes with its own calibration sheet which means every one is different... but the worst part is they only measure it at 9 points and want $50 extra to measure it at 30points... WTF.

I want repeatability and serviceability of MAF element so that when it breaks, I can just drop another sensor in and be done. HPX fits the bill here.

I think both your points are a non issue.

Re the PCV - plenty of people breath to atmosphere and block off the return port so no problem there.

No two turbos work with the same efficiency.  Agreed.  But  what does that matter?  You still have a single MAF as std so you have know way of knowing which turbo is working harder.

Low load is taken care of by bank specific fuel trims and closed loop.  WOT you are looking at your EGT and wideband, and tune round this. 

I haven't tried this yet, but I am going to.  The advantage for me is getting rid of a lot of intake piping.  RS4 Y pipes give power increases but are very pricey.  Without a Y pipe at all, even bigger gains are to be had.

Rick

I just wanted to post an update.

I am currently running Pmas HPX maf sensor in a 3.5" maf housing connecting to 3.5" piping and ending with Amsoil dry cone filter. On the other end it connects to run of the mill RS4 accordion hose, fits perfectly.

I am about 90% done massaging the MAF table. This is about the hardest part of install as the ford crowd uses 9 or 30 point maf table and their ECUs/wideband O2s can figure things out in between but our cars need 512 points MAf table so that has to be interpolated. The MAF came with 30 point table and spreadsheet that allows scaling to different housing sizes.

Anyway, the end result is that that sensor can measure up to 3,600 l/h of air @ 5v (over 800whp worth of air), yes that's over 2,000 more than hitachi sensor can accomplish in 90mm housing while the idle is exactly as good as it was on hitachi sensor in 85mm housing I used to have before.

I will post more details on the setup and perhaps share the map file once I finalize tuning.

Cheers.

That is the kind of thing I love to hear....  Amazing.

It's stuff like this that actually makes me want to keep ME7 in my car (sometimes :P)

Julex, any updates?
I'm still on the fence for my maf choice.

It is in the car and works fine.

I already tuned my Allroad to 2.95 fats with 22-20psi boost on K04s. RPM fats not MPH fats, my car is 10% heavier than S4 with about 10% shorter effective gearing so these two differences even each other out. It takes allroad with same HP about the same time to climb 4200-6500 but it will be physically moving slower at 6500 than S4 due to gearing. Deriving engine performance from fats runs to compare with s4 fats is possible due to this without conversion factors.

Anyway, it is running without a single glitch so it is completely doable.

Cheers.

Where did you read that all of the ProM MAF's are different from each other? Or was that just inferred logic?  I don't think I saw that addressed at all anywhere else when I was looking into the ProM, so I was just curious how sure you are that that would be an issue.

I've seen couple calibration sheets floating on the net and all had different values for their voltages for certain flow values. We are talking the same exact model of MAF. They manually measure that and fill out calibration sheet... This is also the reason why they give you only 9 point sheet by default which is almost useless and want $50 or something like that for 30 point table...

This is also the reason why EPL is only installing this MAF themselves so that they can properly scale maf curve for it.

When I chose HPX MAF, one of my criteria was serviceability of component which standard HPX maf sensor provides but Pro-m doesn't. Should maf die, I would like to just drop new one in instead of running around with car and adjusting fueling again since replacement sensor was behaving differently.

Cool, this is what I was wondering, the pudding.  It's a done deal then.  I'm ordering alot of stuff this weekend!

I just picked up a HPX MAF. How did you wire it up?
According to the Wiki the stock harness has:
+5V
+12V (ign/bat)
ground
signal

I was doing some reading and apparently Ford sensors don't use 5v input? Is this right?
I wired mine like this:
1 - IAT (left unhooked)
2 - IAT (left unhooked)
3 - Sensor signal
4 - Sensor signal ground
5 - Chassis common ground (grounded to the motor)
6 - +12v

hpx to hitachi harness:

Do these work ok?

(http://i65.photobucket.com/albums/h217/MdntRanger50/On3%20turbo%201989%20Mustang%20coupe/2012-10-28_12-55-44_999.jpg)
(http://i65.photobucket.com/albums/h217/MdntRanger50/On3%20turbo%201989%20Mustang%20coupe/2012-10-28_13-38-03_905.jpg)

Besides thanks for revealing the part#, what's are you exactly meaning by what you said? Is that a failed maf?

I meant what i asked, do these really work?
Pictures are by someone who opened a brand new sensor.

I don't think the part number is really helpful, as I think these sensors are stock sensors that are re-calibrated. I'm not 100% on that.

Hi guys, I have been following along for quite a bit now, just starting to get my feet wet with tuning.  I have a FT21 S4, just switched over to 750cc EV14's, went back to a stock tune with stock airbox to get them dialed in, now I am trying to get my HPX maf inline.  I followed Julex's post and advice, used curveExpert to get myself a decent extrap/interp, massaged the near zero entries.

The issue I am having is getting my idle MAF values to sit down near 5g/s.  I am reading 35-40g/s, I have tried changing the MAF wiring, but the result is the same, unless I reverse the +5v signal/return wires, then I see 5.10g/s but throw a million codes for other sensors.  I must have screwed something up.  Tomorrow I will have a peek and see if I can get it on the straight and narrow.

I should also note that the wiring harness is 100% refurbished, stripped back to the ECU pins, new connectors where needed, ICM delete done back to the ECU as per factory BEL harness, as well harness works great with stock maf and airbox, as well reads steady idle of >5g/s when used with my 90mm lightning housing.

Any advice would be appreciated

I capture this thread as I like to have some comparisons between dyno'ed HP at clutch and air flow at MAF (RS4 sensor and housing).

can you help?

Post your MLHFM table. Make sure MLOFS is zero.

PMAS guy shared with me their super secret formula for function transfer so now we can have legitimate and accurate 512 point table without a need for interpolation.

I made this simple spreadsheet (AttacheD). It is self explanatory, I hope. You fill in your MAF diameter in mm and your values come out in column "C". Paste into 512 point MLHFM and you're done.

Thank you very much that this is so useful ;D ;D ;D

They have other versions (updated?) of the transfer function up on their site.