MyE28.com

I used a 3.5" MAF and the ARC-2A box I picked up off of ebay last week. I wasn't sure what to think about the 3.5" MAF at first. I was concerned about idle and low loads, where theres not a whole lot of air to meter, but it actually works really well. Off idle is great, roll on is much improved and the power under boost is noticeably better. It spools the turbo up much quicker too, since it used to just slam the AFM open and go pig rich when you really stepped on it. It will go back to the dyno to see how much better its doing for the same boost pressure with a blow through MAF and fine tuned mixture. But so far, just by the butt dyno, its a big improvement.

Very cool! You can't go wrong with more accurate A/F metering.

Azure wrote:Very cool! You can't go wrong with more accurate A/F metering.

Word. The mechanical door just doesn't handle rapid changes in air density. I had it running great under boost, it just wasnt this nice in between before. And it did make a difference in peak power. The dyno will have the last word on that.

I used that same setup on my N/A 535i. I like it compared to the crappy Flapper door AFM.