What is involved with calibrating a MAF?

Is this all done with chips/piggy back? i.e. can you use any MAF and jsut compensate for the calibration with custom chips and/or piggy back?

Or does a MAF have to be calibrated for a specific car? Injectors? Flow rate, etc.

 

The general principle should be:
The MAF size is choosen after the engine air flow needs. The should obviosly not be to small for the engines air flow, but it should not be unnecessary large either.
Custom chips are made that matches the choosen MAF's airflow curve and size.
Optionally you make fine tuning with a piggy back.

The easy way of doing this is to buy a complete kit with a MAF (sized for your power needs), chips made for that MAF and maybe a piggy back.

 

So the MAF itself is not "calibrated" only controlled by chips and/or piggy back?

 

Todd, the MAF unit is calibrated for a specific air flow range as well as for forced induction, NA, suck through, blow through. Although with the last to I'm not sure if that calibration applies in the univesal MAF meter calibration but I believe it does. The piggy back just massages the voltage signal going back tot he DME to fine tune AFR's (provided you have MAF chips). If I was home I'd send you a cal sheet for you to check out to explain it a bit better.

 

The MAF calibration is the actual voltage curve for a certain air flow. The DME takes the voltage and figures out how much air it corresponds to (this is LOAD), then based on the information it calculates the amount of fuel (based on the known injector size and Fuel Pressure) to inject as well at timing at PT.
If the MAF calibration is too small for your engine, you run out of voltage low in the RPM.

Having a large calibration does not hurt as long as the DME knows about it.. For TRUE MAF chips, the voltage vs. air is a transfer function inside the chip.. I am able to change MAF calibration, change the transfer function in the DME and not have to change anything else..

When you use a PiggyBack to convert MAF signal to look like AFM signal you get all kind of weird behavior especially at/off Idle and Part Throttle. In my opinion, the PB should be used for fine tuning only.

 

let me ask this... I have an Apexi S-AFC II and it has an option on it for it to read a hot wire MAF. Can I calibrate my system using a MAF with it instead of getting another set of chips or controller? otr will I still need to get chips or a piggyback?

John....don't worry...we will hook up soon... I still have ????'s about the injectors and MAF w/chips.. I am still going to go your route once I get everything ready to go.....it may be early spring before I do it though

 

I'm not familiar with your controller, however it's still a PiggyBack. We are back to the same issue, the transfer function in the DME. For best results, transfer function must match the MAF calibration (or AFM).

 

Todd,

Are you looking for a MAF? I have a SFR set-up (as well as a ton of other stuff) that I've been too lazy to put on e-bay.

 

Hey, guys! thanks for the info. Jeremy: Yes, but see below.

Well, I am looking for a MAF, just not a full on MAF kit/piggy back etc.

There are PLENTY of MAF's on ebay that meet the flow requirements of our cars, but all have different calibrations mostly for smaller injectors. Just trying to find out how much work or expense is involved with getting one of those, then jsut have custom chips burned to match. Maybe a piggy back later, but jsut want chips to handle it now. Plug and play, but not at a lot of cost.

I am sure most in here will say, "Just call one of the tuners". I would love to!! Just don't have the $800-1,500 for a MAF package right now or for a while as it always sems some other expenses or bills pop up . Would love to find a cheaper way to do it to hold me over, until i can get a full blow plug and play kit from the vendors down the road.