View Single Post
      03-28-2020, 11:55 PM   #44
Nezil
Major
Nezil's Avatar
1403
Rep
1,466
Posts

Drives: LCI '18 6MT M2
Join Date: Jul 2017
Location: San Francisco Bay Area

iTrader: (0)

Yesterday I captured some more logs to further the investigation of this behaviour. I've decided to start posting here as well because things have gone a bit quiet from proTUNING Freaks over the last few days, and I'd appreciate more thoughts from the experts on here.

First up, is a log going from cruising with ~20% pedal travel to suddenly flooring it, to see the behaviour of the waste gate: https://www.bootmod3.net/log?id=5e7e...0b430c464721a5


I was a bit surprised to see it, but the waste gate stays fully closed when you're cruising, even though there is no boost. I assume this is because boost only builds under load, and cruising isn't load. If load suddenly came, boost would build as quick as possible because the waste gate is already closed.

This is exactly what does happen when I floor it. The waste gate stays closed until boost meets target, then it controls the boost by opening after target is reached. Everything as expected here then.

The next log is a log where I've deliberately tried to take more than 2 seconds per shift, even though I'm flooring it in each gear. The idea here is to see if the waste gate closes immediately under this condition: https://www.bootmod3.net/log?id=5e7e...0b430c46472244


This is a second, to third, to fourth shift, and as you can see, the waste gate does exactly what I'd expect. It actually closes 100% from the very moment I start to get back on the pedal, well before the torque and boost targets go back up high.
__________________
2018 ///M2 LCI, LBB, 6MT...

Current Performance Mods:
CSF FMIC, ER CP, Fabspeed Cat, Aquamist WMI, GFB DV+, NGK 97506, BM3 (Stage 2 93 OTS), CDV delete, UCP, M2C/M3/M4 Strut Brace, M3/M4 Reinforcement Rings
Appreciate 0