The BSFC chart thread (post 'em if you got 'em)

[ever_green]

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).

[H-Man]

Originally Posted by Daox

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.

1ZZ-FE:
4 Cylinder
1.8L
16 Valve

Judging by the power output, the previous engine is the 4a-FE

[Focus-Ak]

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.

[betasniper]

Porsche's Working on the Most Entertaining Cruise Control Ever


Where have I seen this before?

[gafhj]

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:
http://agronomy.emu.ee/vol122/2014_2_1_b5.pdf

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?...

[echo-francis]

found this

[gumby79]

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:
Early..........
..................late
Injector size,
..................6x.009
4x.012
Method of charge air cooling
Water to air
...................air to air
Turbo charger
18cm*2
....................21cm*2

[sendler]

Originally Posted by echo-francis

found this

Which engine/ car is that?

[ever_green]

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).

[ever_green]

another one from epa.gov