Quote:
Originally Posted by MFNATIK
Quote:
Originally Posted by Sedan_Clan
I track boost via AWRON when I drive my car, and during normal driving the S55 uses little to no boost at all. It's only during hard acceleration where it comes on heavy. The pic below was taken on the 241 toll roads in Orange County at about 70 MPH cruising speed (...actually I slowed down to 47 MPH to take the pic, but at 70 MPH on cruise control the boost was identical). I'm using 0 boost. It truly surprises me that your mileage is so bad.
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This makes sense. Its not like the S55 is some puny 1.2L 4 banger haha. It being a 3.0L I6 lends it to having plenty of naturally occurring low end torque. Even under moderate driving, all modern 3.xL NA BMW engines were capable of getting 28-32mpgs on the fwy. I would think the boost in the S55 only needs to come on during hard acceleration, i.e. flooring it 
And yes, that turbo spooling in Sport+ is fun to listen to. What psi are you seeing on the Awron under WOT in the different modes? Have you tried to see what the differences in boost/tuning in Efficient vs. Sport vs. Sport+. I'm curious to see if the boost is stepped or capped between the different modes or if it just comes on sooner or later. |
The boost comes on sooner, but I'll check this week and report back regarding boost at certain speeds. I'll do trial runs up to 100mph.