I figured since I never did see this comparison for us, that I would throw it out there for laughs and giggles. Also, I wanted to ask those of you that have a means to log AirFlow, if you have tried to compare maximum readings with and without airfilter?

While switching bet'n stock MAF and the new 3" MAF I made, I would drive around to make sure all was still working fine. I noticed that (both on shortram mode)...

A32 MAF (with A32 MAF sensor input of "04" on SAFC1)
With AirFilter= 75.5%
Without AirFilter= 78.9%
Difference= 3.4%

I thought that maybe my airfilter is just dirty. I had it on a CAI for a few months after all. I cleaned it up and installed it along with this new 3" MAF...

3" MAF (with Q45 MAF sensor input of "01" on SAFC1)
With AirFilter= 56.6%
Without AirFilter= 59.5%
Difference= 2.9%

I am using the reusable dry-paper Bomz air filter that came with the old CAI.

From this I conclude that from dirty to clean I gained .5% airflow (as relevant as that figure may be). Table is open for discussion

 

More flow, less timing. Stock airbox, or use EMU to advance timing. You're about where I'm @ re: SAFC% reading.

A33 stock intake > A32 stock intake FYI, IMO.

 

Brand/construction type makes a difference too... I have seen a good ~5 whp difference on the dyno between a couple of popular aftermarket brands

 

So post the brand that performs the best!






Sorry for the OT Eddy.

 

OT- Weeeeeerd! about me flowing air in your area, bahahaha!!! I might do one or two last things to get those #s up before I sell the car, I got some stuff tinkering in my head begging to take away from the M3 fund to go after your #s (friendly competition) . For one thing, Im still on 3.0 headers/WSP ypipe *hint hint*, lol. be on the lookout in a few months .

Back on topic- Hmmmmz, thats a good point you bring up there. Whatever minute gains in power the added airflow will create, the ECU will undo by taking out timing. Thus making running no airfilter at the track useless.

Dandy max you speak truff. I just wanted to throw some airflow data to add to the fact.

 

And if you spray hard, it doesn't matter anyway...
.
.

 

His MAF housing diameter is smaller than yours so it's not an apples to apples comparison.

 

It's been dyno'd before though, even w/o a filter, there are very minimal differences if any.

 

Huh?

I'm saying that you two can't really compare S-AFC %'age readings because your MAF housing diameters differ.

 

I know, just throwing that fact out there to support thread information. (re: no noticeable gains w/o filter)

Moot point, but:

Actually, when I was stock,(70mmID) the % was about the same.