I thought I would share the development of my DIY MAF kit. It is by no means as complex or developed as Rogue's or Vitesse's, but I thought I would try it out while I wait for Rogue to complete the S2 version. I'm hoping Joshua can adapt the forthcoming S2 version to suit my non-standard installation due to the supercharger. The pipework will be completely different to Joshua's kit as I am running an intercooler where the normal air filter sits.

The intention of the conversion is to (obviously) get rid of the AFM restriction and get ride of the AFM itself which is a bit of a tight fit and pushes on the underside padding of the hood:


The conversion is pretty simple:

Take one Ford MAF sensor:



one MAF housing



one Ford 6 pin connector



and one DIY voltage converter kit (assembly required). This kit converts input voltage to any output voltage - in essence mimicking the AFM Voltage for a MAF.



An initial voltage fit is gained by using this handy spreadsheet:

VER2.3slot MAF.xls.zip


I then logged the AFM and MAF in parallel and came up with this data.
LM2 Logger Data. This shows how the AFM is currently max'd out before 5000RPM. The MAF keeps going to about 4.5V at max rpm. (AFM=Red, MAF=Green, Black = RPM, O2 = Pink)



The graph below shows the 65,000 data points logged to which I fitted a 2nd order polynomial as a best fit line to the data points:



As you can see the estimated conversion is almost the same as the logged conversion.

The DME code will then be altered to remove temperature vs density correction as this is not needed (or desired) for a MAF conversion

Will get this up and running over the next month as time permits and then report on my impressions.

 

nice work !

 

Did you gain power or Throttle response?

 

Well I'll see when it is all installed

 

Hmmmmm, interesting!

Greg

 

Eric's the man. Nice! Why a Ford MAF?

 

The Ford (made by Hitachi) MAF was chosen for two reasons; Joshua's recommendations as a reliable type, and secondly because there is (relatively) so much information on these MAFs in the community (curve data). The Ford community (eg Mustang) are fairly open to providing information.

 

Great work, Eric! Where did you get the MAF housing from? Looks nicely made.

Cheers,
Mike

 

Thanks Mikey

Good 'ol e(vil)bay

You can buy the aluminium mounting plates separately and then get it welded, but these looked so nicely made and are hassle free.

I just need to order some more silicone pipes to complete. I'm not sure if I'll have time to get it all sorted before Rennsport in 4 weeks.

Cheers

 

So that's a 3" MAF housing? (75mm)

EDIT: just opened the spreadsheet. 3.25", 82mm correct?

 

3.5" external 3.25" internal

 

Eric,

This may seem to be a numpty question, but will this work for a stock S2? Which is code for I am interested if you are considering making more than one!

How is the DME re-code sorted?

Cheers
Greg

 

Greg

Yes it could work for all S2 variants, and the code change is similar. The DME code can be redone by burning a new chip. I'm not intending to go the whole way like Joshua (Rogue Tuning) is planning, so to be clear my solution is much less elegant than Joshua's. My solution is to emulate the AFM, while Joshua is rewriting the code to understand air mass. Code changes will be limited to removing the temp to density conversion required for the AFM and not required for the MAF.

However, to get the tune spot on you should really tune live using an Ostrich Emulator and WBO2 to get the AFRs right. Making the voltage interceptor is quite time consuming (about 2 hours), but the rest is quite simple. You also need a programmer to code the interceptor (which is another kit). If your handy with a soldering iron you could make this kit yourself. I can provide the voltage adjustment curve (it takes about 1/2 an hour to program the interceptor). In a standard S2, the plumbing would be even simpler as the MAF should fit nicely between the airbox and throttle body.

Let's see how successfully this works first!

 

These can work okay, but I think tempature it will need to be retuned from what I understand. This is kind of a band-aid approach to the MAF. You will have less restriction and in theory more power.

Hopefully it works out for you. I would love to learn to tune my car.

 

Correct - this is what Eric was referring to when he said "Code changes will be limited to removing the temp to density conversion".

Cheers,
Mike