Thread: Product review: BPi Flow Stack

More testing on this, here is a comparison of stock intake box vs a flow-stack WAI setup. Dyno is done via virtual dyno from logs.

Constant Mods: SR20DE RR (110k miles), SSAC 2.0" Header, 3" Catback, NEMU ECU with B13 Base Tune and JDM RR Fuel/Timing maps, UR WP Pulley, Z32 MAF, Shell 93 Gas, BKR6EGP Plugs, 6700 Redline (fuel cut starts at 6500)

Stock Intake box:


BPi Flow Stack and Flow Stack filter (coned in on the end)




As you can see the BPi Flow Stack made the run leaner, I knew the flowstack makes the mixture leaner thus I figured I would try leaning out stock airbox mixture too. I cut the fuel back by almost 50% to get it into the same AFR ranges as the flow stack. Results where disappointing, I didn't gain or loose any power. But this shows that stock tune is way too rich and you can restore some MPG's by tuning it a bit.

Thats about right, 6whp. The JWT and Stillen Pop charger are pretty well known to give roughly 6-7whp just bolting it on as a WAI, The BPI is probably cheaper route to go so there is an advantage.

Something to note, this is 6 whp with the hood closed, but driving. Still where the intake sits not too much air should be going through.

^ huh? doesn't 99.99% of folks drive with the hood down?

Yes, but 99.99% of the dyno's are done with hoods open thus more air is available to the Warm air intakes. Thus dyno numbers for WAI's can be as high as dyno numbers for CAI's, but realistically that cold air does a lot.

theory yes, lower the hood on a dyno and we'd see a better real world comparison

I am not sure I agree that it is a better real world comparison. A moving car gets a significant amount of airflow and circulation of air inside the engine bay, and this simply does not occur while sitting stagnant on a dynometer. Perhaps one or more high volume fans moving air through the front fascia and under the chassis with the hood down would be more representative of street driving.