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

[jakobnev]

It looks like the efficiency delta of the engine swamps the ditto of the generator.

There might still sweet spot towards the south east of the 240-zone tho:

[ontherun]

exactly!
in case I will have 'nothing to do' at work, I will try to create a combined map

[Piwoslaw]

VW's 1.4 TSI with cylinder deactivation:


More info here.

[DrInnovation]

Originally Posted by jakobnev

It looks like the efficiency delta of the engine swamps the ditto of the generator.

There might still sweet spot towards the south east of the 240-zone tho:
(see above image.. I cannot post links images yet).

I'm trying to track down the volt BSFC and its source. You posted the chart but not the source, I'm curious where you got it.
Do you have some spec/manual I can site as the source? Since this has a generator chart it seems as if it must be volt/apmera specific since no other 0, generation 3 engine has the same type of generator. I'm curious since some posts about the volt said GM modeling said they could get better efficiency (closer to 50mpg) if they were running at 3500-3800 rpm, but it was not done because it was too noisy. ( google autoblog "where does erev technology go from here" to find an example article). However, that statement about better RPM range is not consistent with your posted BSFC.


Also your plot has a gold line for operational curve, but for the generator I would think it the torque would be at the generator so it would not be matched with the engine torque, which would be a combination of both the generator and the cards travel load. If the total engine load is 110nm @3000rpm, that might be split as 70nm for driving and 40nm for the generator load, or 50 for driving and 60 for generator or any other combination that add up to the total 110nm.

Thus your direct overlay of the operational line for the generator does not make sense to me?

[rmay635703]

I have been looking for a BSFC chart for a C-code 82 GM 6.2ltr diesel for some time.

I found this
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA349754

Better than absolutely nothing, sadly they only consider WOT but it still is quite interesting, fuel consumption per unit of power stays quite flat for an NA diesel

I would be most interested in the NON-wot values.

[mort]

Originally Posted by rmay635703

I have been looking for a BSFC chart for a C-code 82 GM 6.2ltr diesel for some time.

I found this
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA349754

Better than absolutely nothing, sadly they only consider WOT but it still is quite interesting, fuel consumption per unit of power stays quite flat for an NA diesel

I would be most interested in the NON-wot values.

Hi rmay635703,
On page 58[pdf] (A-6[as labeled]) there is a slim hint, idle specific fuel consumption is 10 times higher than at maximum power. 5.83 vs .528. Or on page 83 (B-6) 1.36 to .52 I wonder what that is supposed to represent. Idle exhaust gas temp is just above boiling!

Also, after the GM 6.2 L there is another engine described on page 36 (27) 5.2 L two stroke turbo (Detroit Diesel?), tests on page 41 (32) (and page 122 or C-5 and 156 or D-6). Talk about flat bsfc - from 1800 rpm to 2800 rpm (190 hp to 260 hp) the bsfc goes from .36 to .34 to .38 (39% to 35% eff.)

-mort

[ontherun]

Hi guys,
I quickly went through the document and all the BSFC values are in lb/hr.hp.. So to compare you need to recalculate them to g/hr.kW..

The BSFC idle value on page 58 looks strange to me.. generally, you have higher bsfc on idle, but only ~3 times comparing to best value

[RH77]

Originally Posted by mort

Also, after the GM 6.2 L there is another engine described on page 36 (27) 5.2 L two stroke turbo (Detroit Diesel?), tests on page 41 (32) (and page 122 or C-5 and 156 or D-6). Talk about flat bsfc - from 1800 rpm to 2800 rpm (190 hp to 260 hp) the bsfc goes from .36 to .34 to .38 (39% to 35% eff.)

That's the old DD 6V53 2-stroke (mostly in over-the-road 1960's semi tractors, GM/GMC Heavy Duty "Screamin' Jimmy" trucks/buses, and popular in hydraulic pump and power generators). These preceded the Series 71 and 92 applications, mostly used in transit buses, until emissions took them out of routine service in the late 90's. I do miss the sound, but not the smoke!

RH77

[mk85]

BSFC charts as a picture are nice, but useless to use it in programs like Matlab.
Does anybody know if somewhere raw data/measurement of a BSFC chart for a real engine no matter how old it is?

[Deezler]

You can re-create them pretty easily yourself....

I re-made the BSFC chart for the VW TDI (1.9L ALH engine) just by estimating data points along each constant BSFC line, and interpolating between them to get nice smooth curves that matched the originals. Only took 10 minutes in excel.