legacycentral bbs

when does the stock turbo MAF max out with the stock turbo?
what about with a TD04 or TD05 etc...
just curious as to if i should start looking for a JECS maf before i start looking for a turbo.

-Alex

You can max out the stock MAF with the stock turbo, and an opened up exhaust and intake running stock boost.

I am currently maxing out the stock MAF running 11 psi on the stock VF11. I was right on the limit when I was still running stock boost with just a 3" TBE.

wow! so i guess thats not very good eh??
would that make the car run lean?
what are all the people running bigger turbos using as mafs, just the jecs or is there something better?

thanks
-Alex

OK, the resident JECS MAF expert returns.....


1st off, you NEED some sort of EM, I don't care how basic, to use a different MAF. Why? Cause there is mucho different signal going out and you are going to run like crap, if you even run. ANYTHING that can modify the MAF signal will work.


Basically the stock JECS maf simply gives out a lower voltage across the board. What I am saying now may contradict what I stated previously. This means you will run LEAN at idle if you simply swap out the MAF. ie, you are getting a .6 -.7 signal versus .9-1.0 signal.

I have no idea/memory at which flow level the JECs stock MAF hits 5 volts. But it will allow a significant increase in boost level (probably 15ish psi) but still, this NEEDS some sort of EM to help.

Now...... The big news.

The MODIFIED MAF!

I have taken (and done this more than a few times) a stock JECS MAf, filled in the indentation area with epoxy, milled it out, and then run the maf upwards of 25 psi before it maxes out.

Before






After



milling out




After filling in with goo

ok EM here i come.
so i assume i'm probably maxing out my maf, when it gets maxed out does the computer stop adding fuel or does it take only the reading from the 02 sensor?
how bad is it that its being maxed out?
i just want to make sure i wont blow my car up if i keep running it at 14-15 psi on the stock turbo.

thanks
-Alex

Your injectors go static, ie 100% duty cycle when the MAF maxes out. Not good for power, fuel economy, or fueling control.

Hey Doug,

The milling looks like a great idea but I am wondering if it is for everyone. Too me it looks like the indentation may work like a velocity stack increasing airflow over the sensor. Could milling it out allow more boost becaust it is just flowing less air over the sensor itself giving a false lower reading?

I doubt it is working as a velocity stack, well , much. all I know is that it goes from X to X*.whatever to give a much lower reading. I have run these on a few cars now, all with positive results.

cool, perfect! I am awaiting mine in the mail. Once it arrives and my 550s arrive I am bringing them to my tuner and getting them and some em installed

I never learned the real difference but the JECS AA160 is harder to find then the "160F"'s.
When i worked in the Subie only junk yard we would always need 160's but we would usualy only have the "F"'s we ended up calling them 160F***'s
long, short,.. 160F's should be cheaper.