MAF sensor choppy at WOT

[onspeed]

2002 C5 Z06, mild cam + FAST 90/90. Recently added the fast, trying to get things dialed in again for it.

On dialing in the MAF, I noticed the MAF signal is rather choppy at WOT, sometimes fluctuating as much as 40 g/s. I don't have any old MAF logs to compare with, but I don't think this is normal? Bad/dirty MAF maybe? Air filter is a Blackwing, maf directly behind it. Any chance a vacuum leak would cause it? I'm not 100% the MAP sensor is leak-free as the hole on the FAST is a bit larger than the LS6.

Inserted screen shot of the graph and also copy of the log (3rd gear WOT pull around 21 minutes in)

maf.pngmaftest3.hpl

[dermotw]

Well.... I think it's fairly normal (..."I'm not an expert!") although the amount of fluctuation you have is a lot, certainly more than mine, yours is about double mine. Depends on intake layout and blah blah. Firebird's (like mine) have a very short air path to the MAF and thats probably part of it, when you add in alterations to the rest of the air path, it becomes worse (I assume). Hopefully it doesn't vary at steady throttle though...

Adding a socalled honeycomb (an airflow management device) in front of the MAF may help... or not, lol, but it did improve mine.

http://www.saxonpc.com/100mm-cells-for-100.html

Here's mine for comparison, the scale is different notice;

mine.JPG


kr D.

[onspeed]

Thanks, few of the guys on 'tech says its looks normal to them as well. Probably going to pull the intake again regardless to tap the MAP sensor hole and run the sensor remotely with a 1/4" pipe fitting.

[MMGT1]

The honeycomb from saxonpc and get a piece of storm door screening and attach to backside of MAF. (Stainless if possible) It will smooth the signal, it works. Straighter the flow the better that signal will look.