Which MAF for 12psi of boost?

I can't say for sure because I havent tried the stock MAF. But I am in the process of installing a D1SC w/intercooler on my 01. When I was researching the subject everything I was told or read says NO. I went with the Pro-M 80mm univer. and 42#ers. Not that I prefer the Pro-M I really dont have a preference but I rely heavily on all these boards to keep me from repeating mistakes others have made. And it seems most go with the Pro-M so I did to assuming that if I should encounter problems tuning it I could get some help or suggestions from others. I wish I could tell you how it works but I havent even started the car yet.

Not sure on the stock MAF but isn't the Lightning MAF an option?

Two things:

1. The MAF is calibrated for 24lb injectors, so it won't work.
2. You need a bigger MAF...get the Lightning 90mm MAF....it flows more, and it's OEM so it's easy to tune with.

This subject was very confusing for me before I educated myself on the topic. Maybe I can shed some light on it. Its not so much that its calibrated for 24# injectors nor is it the flow of the meter. When a company manufactures and calibrates a MAF for xx# injectors what they are really saying is this meter is for a xxxhp motor. Let me attempt a crude explanation. I think we all know the MAF sends a signal to the processor indicating how much air the engine is using. This signal is a dc voltage from 0vdc-5vdc the EEC cannot recognize a voltage >5vdc. The injector size is something we all recognize I think this why everyone refers to it when speaking of a MAF. The manufacturer uses the injector size to calculate the maximum hp that size injector will support. Then you can calculate the air mass required to achieve that hp level. Which is what the meter will actually measure. Once you know that you can calibrate your MAF to read from 0 to what ever you calculated your max to be. Example if you have 42# injectors (these are just numbers I am throwing around not true figures) and calculate that they will support a max of 500hp and you need 1000 kg/hr of air to achieve that then you would calibrate your MAF to read 0vdc @0 kg/hr and 5vdc @1000 kg/hr. When you buy a new MAF you will get a flow sheet that is unique to your MAF. On this sheet is the results of the manufacturers calibration. They will nomally have about 10 different points on them showing a voltage and the air mass that voltage corresponds to. When you plot them on a graph a curved line is born. This is referred to as the MAF transfer rate and that is what needs to be entered into the EEC. So it will know precisely how much air mass is entering the engine. Without an accurate measurement the EEC will never be able work as Ford intended. With that said you should understand that it is not necessarily the physical size of the MAF (ie. 70,80,90mm diameter) but how much hp can the electronics measure. I upgraded my stock 80mm to a Pro-m 80mm no difference in the physical size of the meter the difference is in how much air mass or hp can it measure.
Now the Lightning unit can definately measure more hp than the stock cobra unit. But from the mods you are listing I would assume you are in the same league as me. And I was told I would probably max out a LMAF. Also if you look down inside your MAF you will see a little tube with a couple wires in it. Looks like a light bulb filament but its not. That little tube is where it all happens. Sometimes out of necessity you have to mount your MAF in a location and orientation other than stock. When you do this that little tube usually ends up somewhere other than where Ford intended it to be. The location of that tube is critical to an accurate measurement. Because the air doesnt necessarily flow through every square mm evenly. More air may flow through one half of tube than the other. So your measurement will vary depending on how much of that flow ends up going through that little tube. That is why I would say a LMAF would not be easier to tune with. You might get lucky and get it positioned correctly but if you dont it will never work right. Thats why it works for some people and not others. Now Ford has the resources to ensure it is placed perfectly on a stock engine. However you and I do not. Thats where the univer comes in. If you get the chance to check one of them out. You will see many little tubes all the way around the diameter of the meter. So instead of one doing the measuring it has about 10 then it averages them. The result is a more accurate reading of the air mass going through the meter. It also allows you to mount it in any position needed. And that is just what the doctor ordered when you are installing a SC in the tight confines of a Mustang. I could go on about the subject all nite but my fingers are all cramped up now and this post is getting pretty long.

Another vote for the Pro-M Univer. Seems to really shine in Procharged applications. I too pegged my LMAF first time around.

peace

I also pegged my LMAF at 6500rpm. So, I'll be upgrading to a pro-m this spring.

520rwhp, 440rwtq @ 6500rpm
10psi Novi 2000

The LMaf will definitely be pegged. Another vote for Pro-M Univ.

99SVTAddict said:

Two things:

1. The MAF is calibrated for 24lb injectors, so it won't work.
2. You need a bigger MAF...get the Lightning 90mm MAF....it flows more, and it's OEM so it's easy to tune with.

Click to expand...

Ford OEM meters are not injector calibrated. that is done in the EEC.

I've swapped in a 408 Windsor with AFR heads and turbo'ed it on a China GT45. at 7PSI the meter is maxed. i'm looking for a good answer for this as well as i'm looking to run 15-18 psi. any suggestions?