[Twistm4]

Just curious if anyone has done some tests with different air intake configurations in regards to tuning/logging/dyno data. I see manufacturers claim one thing then private dyno sessions claim another. So I am looking at 3 different air intake configs so far and comparing the same three points of data in different conditions. IAT, Boost and Wastegate duty cycle. All in the same gear, on the same road at the same RPM.

Has anyone tried modifying their stock airbox for giggles? I know on the n54s people had luck with opening up the bottom of the boxes so more air could get into the filter when the car was not moving as fast. Seeing as I am focused on drag racing more and more, I cut a series of holes in my bottom airbox to research any differences in the data.

Three configs (all using Macht Shnell Air feed Scoops): OEM with BMC Filters, Injen evolution Intake and OEM modified with Drop ins.


Injen Evolution: Average DRAGY 60-130 = 7.7

IAT: 84 | 86 | 82

Boost: 23.2 | 23.2 | 23.1

WGDC: 92.4 | 93 | 93.4

OEM Intake with Drop Ins: Average Dragy 60-130 = 7.5

IAT: 95 | 102 | 100

Boost: 23.2 | 23.1 | 22.8

WGDC: 91.1 | 92.9 | 92.3

Modified Oem Intake with Drop ins: Average Dragy 60-130 = 7.4!

IAT: 75 | 90 | 90

Boost: 22.6 | 23.1 | 23.2

WGDC: 88.5 | 90.6 | 90.8

100-200kmh 6.43, 6.11, 6.04

CTS INTAKES Average Dragy 60-130 = 7.38 (should add weather started to cool)

FINAL MODS CTS Intakes + Air Feeds + Fully Catless Straight Pipe Exhaust Average Dragy 60-130 = 7.1

FINAL FINAL MODS = CUSTOM TUNE, AIR FEEDS, DROP INS, MODIFIED OEMS Average Dragy 6.5-6.7 60-130

Update 11/21 Broke stock turbo 60-130 and 100-200kmh world record at 6.3 and 5.40 using final mods version above.

Conclusion: Adding one more variable to study was "MAF Actual Channel." Using 6000rpm in 4th gear WOT as a baseline, 40 logs were averaged total with 10 from CTS, 10 from Injen, 10 from OEM and a separate test of 10 from OEM Custom tune. Oem intake 4.4 average higher at this range. However, it is important to note it was rare to find this channel being LOWER with oem set up at this range compared to aftermarkets. Even in more adverse conditions and higher DA the oem had higher MAF readings (placement of maf or indicator of flow??) V DYNO Logs and MAF readings at given rpm same gear same load indicate best performing set up to be OEM with DROP ins with air feeds and cut out lower sections.
WGDC on 29psi to 25psi @redline is the same in winter as MHD stage 2 was at 4-5 less psi with 2 other aftermarket intakes.


V Dyno reports a current 610-630whp dynojet number. Car traps 133-136 depending on DA, temp and weight. MHD ots tune logs report 552whp on VDyno once calibrated correctly. EXACTLY what car dynoed on real dynojet on MHD 2+ e30. Current tune dyno results to follow soon.

Side NOTE: VANOS TUNING DRASTICALLY INFLUENCES WGDC AT CONSTANT BOOST PRESSURES. For instance, 23psi with 8* IN Vanos Degrees could be 88% WGDC, whereas with 3* (more aggressive overlap) could be 95%. All averages were taken on the same tune prior to custom tuning.

Theory: Integrated velocity stack in OEM intake allows greater airflow over 3" mandrel or smooth tubing. Surface area of filter may be larger. I need to get my hands on eventuri now to see if there truly is a higher flower air intake set up.