Modifiying Stock MAF's!
 

So who has done it and has words of advice.
Anything from moving to a different tube, changing the MAF tables, adding a resistor to the signal wire, a voltage clamp... I am in the process of trying all of these and want to see what others have done!
Working with a bosch MAF off a 95 5series bmw.
It maxes out at like 10psi around 4.5k and pulls all my timing so my AFRs shoot to nines and I lose a ton of power.
I need some more ideas to mess with this MAF lads. Anyone resistor or clamp successfully?
Would that make my last column of values under load/voltage just be used for the entire range of 10-25psi from 4-7k? :1

Re: Modifiying Stock MAF's!
 

I have moved dual mafs from the skyline gtr from the stock size tube to a 3" tube. At 500whp they read 4.3vdc and better than stock driveability with some tuning. I didn't touch the transfer (vq table in nissanese) table at all. I fired up the car with no changes to start with, then changed the k-value by the percentage needed to achieve a 14.7:1 afr after the engine was warm.

I have also dropped voltage via a resistor. Retuned as per above.

I have also bypassed the maf by installing another pipe with a filter behind the maf. This achieves the same thing as a larger tube without having to touch the stock maf. I knew by how much I wanted to increase the size so the bypass was made the same size as the larger injectors were over stock. I then retuned the spark table and did a bit of fine tuning on the main fuel table.

I much prefer bypassing as it circumvents failsafe's such as min maf voltage and lowers the restriction the maf element presents to the inlet passage.

Re: Modifiying Stock MAF's!
 

larger maf body for maf sensors (separate from body) basically cut the flow it sees down.

if it's one unit like older cars liked to use, then i dunno. resistor or maf hack ftw

Re: Modifiying Stock MAF's!
 

You might be better off just running a decent MAF out of the gate. Get one of the 3.5" GM/Hitachi units, run a freq-volt converter if your ECU is expecting a 5/12 volt hotwire unit, tweak MAF table to suit.

Re: Modifiying Stock MAF's!
 

there is an 803 porsche hfm that with my current tuning capabilities would be plug and play but costs ~250$ new
I am trying to make 100% sure that I am beyond working with the stocker before I upgrade, thats the easy way out.

Re: Modifiying Stock MAF's!
 

Contact Hitchhikkr about a better priceon that MAF, if you have to go that route.

Re: Modifiying Stock MAF's!
 

No need because....

Those MAF are notorious for failure. Anything so much as a K&N filter will send them to their death. You will be bringing on more problems than you solve.

Am I wrong in thinking that you can use the MAF translator or the PROversion? It has a function to convert to a GM style map sensor, or run the 3"-3.5" gm MAF sensors. $400 bux doesnt sound too bad. I know they work well on dsms and supras, couldnt be too far off on bosch system.

Re: Modifiying Stock MAF's!
 

You can build a freq-voltage converter for under $10. If you can tweak your MAF tables in the ECU no need for the whole MAF-T package.

Re: Modifiying Stock MAF's!
 

OIC, good to know.

Re: Modifiying Stock MAF's!
 

http://www.national.com/ds/LM/LM2907.pdf

Common logic 2907/2917 does the trick. I have a couple somewhere in a bin as I was going to help Pokey do a poor man's MAF-T on his Eclipse before he got angry with the thing and beat all it's windows out with a crowbar.