Phil type 951

this looks kinda cool.<ul><li><a href="http://autospeed.com/cms/A_2418/article.html">http://autospeed.com/cms/A_2418/article.html</a</li></ul>

Mat Indukts Lambos

with a wideband monitor. Problem I've seen with it, is it also piggybacks on the throttle signal, which can set a throttle implausible signal dtc occasionally, only on OEM &amp; GIAC software, haven't tried APR. Aside from that, it works well. Also, depending on the model year car it's used on, you'll need the rpm signal generator too, and there's a trick to hooking that up....

xr4tic

may not work with the nDBW ECU without some redesigning.

Due to the resistor in the ECU between the MAF and the A/D converter, the MAFs on our cars actually hit 5.5V, and the ECU will only see 5V.

So unless this thing can input AND output voltages higher than 5.0V, then it will not work.

I'm not sure if the DBW ECUs are the same.

Phil type 951

here are the specs.

Voltage input: any voltage from 0 to 14.4V
Voltage Output: 0 to 1V, 0 to 5V or 0 to 12V plus offset
Offset Adjustment: +/-127 steps corresponding to 19.6mV for 5V range
Maximum Offset adjustment: +/- 0.5V with 1V range +/-2.5V with 5V range or +/-6V with 12V range (optional finer resolution reducing adjustment range by 5)
Input adjustment points: 1 to 128 corresponding to 39mV steps from 0 to 5V for 5V range
Input to output response time for offset change: 5ms

so it looks like 5v is the max input/output.

wouldnt a larger maf housing and or a maf clamp help corect this issue?

For example, the resistor apr installs on the ecu for NDBW stage three cars. I assume this is basically a MAF clamp to restrict voltage into the ecu.

Does the actual voltage matter? I would think that if you installed a larger maf housing the voltage would be lowered across the board and never reach maximum. Then you could adjust the fuel trim as needed via this, or another system. I'm probably missing something.

xr4tic

The stock MAF transfer function equates 5V to 675kg/hr and 4.5V to 540kg/hr

So that's:
5.5V MAF = 675
5.0V MAF = 540

a 3" MAF housing is ~15% bigger than a 2.5" housing, but 675/540 is 25% bigger.

Your housing would have to be 25% bigger, just to have the same flow range as the stock MAF setup.

The APR resistor does lower the voltage that the ECU sees, so the MAF actually outputs a higher voltage for the higher flow rates (I was told Ford MAFS are pretty stable up to 7V output from Pro-M, I would assume the Bosch stuff probably can go as high as at least 6V)