u/BMW40i

Hey guys, got a 2018 F36 440i on MHD Stage 2 OTS map with catless 4.5” downpipes and XHP Stage 3. Recently did some data logging and wanted to share the figures and get some opinions from people who have been through similar.

Been having some concerns about heat soak and knock so decided to do 6 pulls — 3 on the 91 map and 3 on the 93 map, all in 3rd gear on the same stretch of road. Ambient temp was around 17-18°C. Also did a 0-100 pull in Sports mode.

Current setup:

•	MHD Stage 2 OTS v3.9

•	Catless 4.5” downpipes

•	XHP Stage 3

•	Sports cooling mode

•	NGK 94201 plugs (stock heat range, 10k miles on them)

•	Stock intercooler

Here’s the data:

IAT pre-turbo ranged from 93°F up to 113°F across all pulls

Charge air temps post-intercooler ranged from 133°F up to 302°F on the hardest pull

91 map boost: 17.2 PSI target, 18.2 PSI actual max

93 map boost: 18.9 PSI target, 22.5 PSI actual max

0-100 pull boost: 23.8 PSI max

Timing corrections on 91 map were mostly clean — worst was −3.0° on Cyl1 at around 2% frequency on pull 1, 15% on pull 2

93 map was significantly worse — Cyl6 hitting −4.9° at 50% frequency, Cyl1 hitting −4.2° at 59% frequency

0-100 pull worst: Cyl6 at −5.7° and Cyl1 at −4.9°, both at 60-69% frequency

AFR tracking target well at 13.48-13.58 across all pulls

Oil pressure solid at 77-82 PSI throughout

Oil temp 212-216°F

Coolant 201-208°F

Transmission temp 185-190°F after all 6 pulls

EGT ranging from 1143°F up to 1618°F on the hardest pull

LTFT: −0.08% on 91 map, −1.02% on 93 map

Main things I’ve noticed are the charge air temps getting very high under load, the 93 map producing significantly more knock than the 91 map despite being on good fuel (Shell V-Power and Tesco 99 only), and the over-boost on the 93 map hitting 3-4 PSI above target.

Has anyone else seen similar figures on a B58 Stage 2 setup? Particularly interested in the really high IAT as apprently charge air should be arounrd 70 degrees hotter than ambient temp so me hitting 150 degrees Celsius is abit crazy.

what steps made the biggest difference to knock and timing corrections.

Any advice or similar experiences appreciated 🙏

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u/BMW40i — 26 days ago