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Old 06-24-2015, 10:15 AM   #281 (permalink)
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this is one of the best articles i read in regards to relations of AFR and power/BSFC.

Engine Management

Basically best economy is stated to be achieved at 0.625 FAR. that's roughly 16:1 AFR. Best BSFC is achieved at 86 lbs/hr of fuel flow which for this engine is roughly about 15.6:1 AFR. The best thing about these measurements are that it's under vacuum (not full throttle) and at a nominal 2500 RPM. This confirms my experience with higher fuel consumption when I lean the mixture past 16:1 AFR despite running more ignition timing. I found 15.5:1 AFR with some EGR is best for my engine to achieve 39 mpg highway (good for a 2.5L 3300lbs 4WD vehicle).

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Old 06-28-2015, 01:18 AM   #282 (permalink)
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Originally Posted by Daox View Post
Here is the BSFC chart for Toyota's original 1ZZ-FE when they developed it back in 1998. Interesting how the lowest BSFC is so high in the rpm band. It would be really great to get updated info on the newer versions of the 1ZZ. I know there were some fairly descent changes to it over the years.

4 Cylinder
16 Valve

Judging by the power output, the previous engine is the 4a-FE
Getting sensor data off of a pre OBDII Toyota ECU via TDCL.
All of this is on E10: Project E is my current focus.

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Old 06-28-2015, 03:45 AM   #283 (permalink)
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One observation from looking at all the BSFC charts in this thread is that for optimum fuel efficiency over a period of time (i.e. many trips, days, months) it is best to target under-shooting the sweet spot a bit. This is because the gradient between the contour lines is shallower on the underside. When one over-shoots the sweet spot, it is easy to get into quite higher fuel consumption situation. Missing the sweet spot a bit on the lower side of the doughnut hole matters less.
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Old 08-03-2015, 02:23 AM   #284 (permalink)
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Porsche's Working on the Most Entertaining Cruise Control Ever

Where have I seen this before?

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Old 08-04-2015, 02:24 PM   #285 (permalink)
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I was looking for a BSFC chart for my 2003 Fabia 1.2 12v. I found one for its 6v sibling, but only for wide open throttle:

First, I have some reservation for the data. There's a summary table that shows specific fuel consumption to be 274 g/kWh. But at which point? According to the chart, the lowest point is ~250. The point of max torque is ~260 and the point of max power is near 400.
Second, their engine made 13.5% more power than advertised.
Anyway, is the chart at least somewhat relevant for me?
Any suggestion as to what to expect at less than WOT?
Or, maybe, just maybe, someone has seen a better chart?...
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Old 11-24-2015, 10:53 AM   #286 (permalink)
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found this
Best Tank (1557.2 Km): 2.57 LHK (91.63 MPG (US) )
Best Highway Trip (~36.8 Km): 2.16 LHK (109 MPG (US) )
Best Commute Trip avg (73.8 Km ): 2.33 LHK (101 MPG (US) )
Echo-Troll Modding Thread

I know i dont have a very good write-up
no lean-burn? no good gear ratio? p&g is the answer
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Old 02-05-2017, 05:17 AM   #287 (permalink)
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Cummins 6BT 5.9-160, 5.9 160 HP

Finaly found the BSFC chart for a Cummins B 5.9-160.
I don't know if this is for the early 89-91.4 water to air intercooler or the late 91.5-93 air to air intercooler. The majir differences between them are:
Injector size,
Method of charge air cooling
Water to air
...................air to air
Turbo charger
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Old 02-05-2017, 08:12 AM   #288 (permalink)
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Originally Posted by echo-francis View Post
found this
Which engine/ car is that?
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Old 05-08-2017, 11:01 AM   #289 (permalink)
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gueff - '19 Mercedes Benz A250 4MATIC AMG
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Attached is the Mazda3/Miata 2.0 NA Skyactiv BSFC with the 13:1 compression heads. I recently bought a new standard 2.0 and without any special hypermiling tactics I can easily score 41-43mpg on the freeway @70mph and the engine is still not even broken in yet. At 100kph or 62mph, car cruises at 2200 rpm which is right at it's bsfc sweetspot. Scangauge indicates 40-50% load at cruising which pretty much means ~36% BTE...mostly thanks to it's very wide ratio VVT system which retards CAM timing up to -70* at low engine loads (artificially reducing displacement).
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Old 05-08-2017, 02:03 PM   #290 (permalink)
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gueff - '19 Mercedes Benz A250 4MATIC AMG
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another one from epa.gov

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