With so many questions about meter "clocking" and a/f this may help
 

Why does it seem the aftermarket cai builders like steeda,k-n, php ect make their kits with the meter in a postion that isn't like the ford factory position?Because it DOES LEAN the a/f mixture...and this will make more power on a stock car. Why do you guys think ford makes the mass air sensor with a 4 bolt flange on it that only bolts on ONE WAY to the factory air box?? So the a/f will be consistant, something that is very important when you are trying to get 100,000 plus mileage from the supercharged cobra if you are ford! When we send a custom tune out to a mail order customer we insist for the safety of their own engine that the meter be in the factory 10:00 position so the maf transfer functions will be correct...this is a big deal on untuned cars guys...the a/f changes greatly on just a 5 percent rotoation of the meter! :eek: None of this meter position matters if the car is getting custom tuned live and you are data logging and checking a/f while tuning, but if your not keep this in mind because your engine's life might be at risk...

NOTE!! Here are some pictures showing the the meter positions...the first one shows how the k-n,steeda ect. mount the meter"straight up", the other two show the factory type of mounting angle, which is prefered for factory type maf transfer functions...hope this explains more !!


http://www.steeda.ca/tech_articles/clocking/1.jpg
http://www.steeda.ca/tech_articles/clocking/2.jpg
http://www.steeda.ca/tech_articles/clocking/3.jpg
http://www.steeda.ca/tech_articles/clocking/4.jpg

yeah ive read about this. A few say to rotate it to the 3 o'clock postion if you have idle problems or to make more power. and as you say, it does that by leaning it out some. Also it can allow the meter to get a better reading ive read.

just as an example i used a pic from WMS

http://www.westernmotorsports.ca/wms...citysystem.jpg

I stay away from Pro-M and C&L, etc as much as possible. If you can use an OEM style meter (Lightning, SCT) you are MUCH better off.

why you stay away .. i have a C&L whit Ford sensor and i never have any idle or acceleration problem .. but i will try to clock it at 3 o'clock just to see if i feel a difference .

BTW how many km are your steeda store is from montreal , if im interested to buy you some new stuff or put my mustang on your dyno for a tune :tup

Non OEM Meters are not very accurate and reliable compared to OEM's. If I can use an OEM style MAF like a Lightning or SCT Maf I will. Sometimes calibration is not done proper, etc (but let's keep this thread about clocking..we can start a new one on maf manufacturers later)

We are about 5.5hrs from downtown Montreal if you are driving in no traffic at abo 125km/h

You can order part's online or over the telephone and we will ship them out the same day, if they are in stock and you will recieve them next day via Fedex.

If you know of a dyno near you I am more then happy to make the trip down and tune your car. We do off site tuning as well as here locally.

thanks for your help i will need good tuner whit my next combo :Stock long block w/ single turbo or vortech ...

for now if i clock my maf .. should i see a difference ?

You might, but I would leave it stock. I will never suggest rotating the maf away from the stock position. If I am tuning the vehicle in person, I do not really mind where it is.

OK, now. I totally agree with your statement of using OEM maffs rather than aftermarket. I actually preach this to all of my customers. I have had more issues with Granetteli maff's than Pro-M BY FAR. Now who makes the SCT maff???*cough* granetteli *cough* I think the fact you are a dealer may have something to do with your choice there. BY FAR the most reliable maff is an OEM one. Far better than a SCT maff or ANY other maff on the market. The only time I would reccomend going to a SCT maff (or any other maff for that matter) is if you are pegging the maff at 4.9 volts. There are also other options such as a Maff X-tender from Zone - 5 Performance http://www.mafterburner.com/mafxtender.htm
The Maf-IA will also be released from Diablo. Both use factory mass air flow sensors and therefore have probably the most dependable electronics. :cheers:

The SCT MAF is the unit of choice by all Diablo, SCT dealers and anyone else. I could care what I use or preach as I sell everything

The Meter is produced by Hitachi and is actually a 90mm Ford Lightning Housing with Granetteli electronics. SCT tested multiple pro-m meter's and out of about 30, none were with in range of eachother..they are not consistant. The BIGGEST diablo tuner supports and swears by this maf as well.

Not the choice of ALL Diablo tuners Paul ;) :cheers:

If you have tried one and can honestly say it is not better, more accurate and allows for better WOT and drive characteristics and easier to work with..something is up :confused:

try clocking it to 10 :chacha:

Actually I am using the Maf X-Tenders with the Ford sensor and they are working well. I still trust the base electronics of a Ford sensor more than the SCT one.

I GUARNTEE the SCT Meters, made by the same company who makes ford meters with tweaked electronics are just as accurate.

MJ's extenders are great as well

OK latest update from dyno today. The car = 2001 Bullit.
Mods :
Diablosport chip
Granetelli Maff and filter
Customer was concerned with detonation and loss of power at high rpm.
First answer to what he could do was....

wait for it....

"Remove that POS GMS and put on the stock one, I have seen cars make more power and cure drivability problems by removing them and using stock."

So he does that last night and brings it to the dyno.
we make a pull with the stock maff and k&n
255rwhp with consistant 12.8 a/f
We then swap the GMS unit with filter back in.....
225rwhp with 16:1 a/f

So I go back to my previous reccomendation...
Stick with the stock mass air flow sensor untill it will no longer flow enough air for the engine, then upgrade to a larger FORD meter and use a maff extender. If this was a supercharged engine not just N/A... it would be to late :banghead:

i dont think either of ya will win the argument. Lets just keep it clean :tup

Yes, a maf like that will need a custom tune...but once it is custom tuned it will show way better results when tuned

We are both right, just have different choices :cheers:

Actually I did a custom tune with one on a 99 cobra, replaced it with stock meter and retuned. 10rwhp more. It to was a GMS unit. In all honesty, a aftermarket maff is NOT required and will NOT make more power on a tuned car unless the meter is pegged. Save that extra $400 or so for something better.