prossi

so i read the thread posted below and was really interested in doing this conversion on my 951, so i bought a ford taurus MAF at first i followed the wiring that was posted by sweet9fourtyfour and i had some drivability issues the car was WAAAAAAY rich and had a dead spot where it was making no power. so i did some research and ended up removing the stock iat sensor since it wasnt needed...instead of using it like sweet9fourtyfour did. Car was still running very rich since the MAF was sending incorrect signal....so in order to get the conversion to work i made restrictor nozzels to mount in the MAF..see added pic. i made several sizes for tuning the car my dyno session is saturday and ill post before and after results since i dynoed it before doing the conversion.
also you need an air bypass in the intake tube somewhere post MAF.

i will post specific restrictor sizes and write up after i get the dyno results and see if this was a success...my butt dyno tells me it was!

here is the original thread
https://rennlist.com/forums/924-931-...-dyno-run.html

V2Rocket

thats really clever putting a restrictor in there.

im curious though, how are you getting incoming air temperature to the DME? did you use the MAF's output signal for temperature in addition to the voltage output signal?

im doing the same thing to my NA with a contour maf but i have it wired right now to keep using the IAT because as far as i know the DME couldnt understand the MAF's temp signal.

also why do you need a bypass?

blown 944

Have you logged the AFR's in the upper rpms??

If it scales properly that is a good idea, similiar to changing sample tubes in the mustangs MAF.

If it is close you could use a piggyback to get it perfect. I am curious about the AIT sensor , I have in the past just used the factory AIT (I think it is between pins 1&4 on the plug). I then used a GM AIT as the resistance seems close.

Rogue_Ant

If you use a MAF & AIT without making on-chip changes then your tune will drift with temp changes. This is due to 'double-compensation' being done for air-temp. One by the MAF itself, and the other by the DME.

Furthermore, the DME does more then just adjust fueling from the AIT signal input...

Not saying that either way won't work. However it will never be 'right' without making on-chip changes.


-Rogue

V2Rocket

Rogue, do you think that the MAF's temperature output will be understandable by the DME?

prossi

this is why i removed the stock one, with it in the car was just full rich on the AFR guage and had driveability issues. I am currently running Guru chips but my pal at a local shop is working on burning a custom chip after we get some data from the dyno

prossi

as of now it seems so. I am using my AFR guage to monitor but i wont know exact numbers until im on the dyno. how the car currently sits the guage reads between normal and goes slightly rich in the upper RPMs which seems to be working well with the amount of boost im running
the guage readings are VERY close to what i was getting with the stock afm

black944 turbo

My understanding is with a maf you don't need an ait due to the fact a maf reads the mass of the air which takes into consideration density and temp. Is this correct?

prossi

yep...as far as i know

blown 944

IMO that depends on how close the AIT output on the MAF unit is compared to the factory unit.

Some MAF's don't have an AIT output at all and need the separate AIT.

However, it is a bit more complex than just that b/c the curve is dictated by the MAF output and "that curve " changes with AIT and the DME has to be properly mapped to keep it sorted properly. There is only one vendor at the moment that has that capability AFAIK. That is why most other units require a PB.

prossi

here are some more pics..i do plan on moving it to in front of the coolant tank where most aftermarket companies put them

Rogue_Ant

It really depends on the volts vs temp scale of the MAF you are using. The DME can be made to understand different scaling, but definitely requires some changes to the code.

Really, if the AIT scaling is similar then the best thing to do would be to flatten the AIT fueling on-chip. And use it as is.


-Rogue

Rogue_Ant

With a MAF you should not need an AIT for fueling purposes. However, the DME uses the AIT for more then just fueling. And as such, I would recommend providing an AIT signal to the DME and flattening the AIT fueling compensation on chip.

Furthermore, the altitude sensor needs to be taken out of the loop, or this compensation also zero'ed on chip.


-Rogue

V2Rocket

OP, did you just wire the MAF to the AFM harness or do you use a piggyback?

alxdgr8

Didn't the guy that originally did this dyno the car and it made less power with the MAF and never ran correctly?...so why are you doing this? You NEED some sort of translator to convert the signals, otherwise it might run correctly in some places and not in others. Sounds like a good way to blow an engine.

That and you need to recirculate your BOV as you are losing metered air.