AutoSpeed: "FuelSmart" device: sort of a live BSFC indicator

[Julian Edgar]

I am not going to reveal AutoSpeed content months ahead of time, but in short the approach we're going to take is not very much like you have stated.

[dcb]

<sigh> ok throttle and map, and hope the engine is stoic, whatever. RPM would probably be useful too.

Seriously, do you not think this would benefit from being open source? I mean the target audience has to be pretty small to begin with (manual trans with map sensor), I don't think you are securing vast fortunes here by keeping secrets.

[gone-ot]

...I'm willing to take a "wait and see" attitude, and (of course) authors and publishers (like fine wine makers) typically don't like to "...spill (all) the beans..." before their time.

...been there, done that (author, articles, books).

[dcb]

Yah, but bsfc maps from ordinary driving is still a little far fetched.

[gone-ot]

...a little (lot?) technological day-dreaming can envision the possibility of using pre-programmed eproms containing computer-generated 3-dimensional maps as "seeds" upon which 'real-world' values are "scaled" and overlaid upon those meager portions of the BSFC map that everyday driving "covers."

...but, I'm not writing the article.

[Julian Edgar]

Seriously, do you not think this would benefit from being open source? I mean the target audience has to be pretty small to begin with (manual trans with map sensor), I don't think you are securing vast fortunes here by keeping secrets.

AutoSpeed is a commercial site.

I think that FuelSmart does about 80 per cent as well as a live BSFC indicator would. AutoSpeed and eLabtronics have devised a system that I think would work very well as a BSFC indicator, but it is yet to be tested or even developed. So, as I said, it certainly won't be out soon.

[dcb]

yah yah teleman, I do that stuff in my sleep. I just think this venue is better suited to real openness and sharing of ideas, not infomercials.

[cfg83]

dcb -

Originally Posted by dcb

Yah, but bsfc maps from ordinary driving is still a little far
fetched.

Really? Pardon me for not doing my research, but doesn't the MPGuino have access to RPM and fuel injector pulse widths? If you also had access to the LOD parameter from the OBDII port, I think you'd have all the parts needed to make a BSFC map, right?

Maybe the map would be all over the place, but once you've gathered enough data, couldn't you derive a decent "real world" BSFC map? Also, it doesn't matter what the pure fuel consumption is, only the relative number, right?!?!?!

CarloSW2

[dcb]

Hmm... My main concern was the accuracy of such a map and the conclusions drawn from it.

But if you have accurate fuel consumption data then that would certainly help with the FC (fuel consumption) part of the BSFC graph.

RPM is an easy part, some injector signals carry rpm info too, but plenty of other sources too.

So how accurate is inferred LOD compared to a dynamometer? Here is a little info How to calculate Engine Load? [Archive] - Innovate Motorsports Forum , if no MAF, then need things like MAP, IAT, and a Volumetric Efficiency table (very much engine dependant), and I'm surprised injection timing isn't in there (I suppose that is more of an output from an ECU perspective).

So accurate lod from MAP seems to take a fair amount of prior knowledge about the engine and some more sensor taps. But I'll buy %80 accuracy overall Julian, that sounds attainable, not sure how useful it is though.


Another consideration if you focus only on the engine parameters you effectively shut out many of the real world variables, which is of course the point of a BSFC map but has a downside i.e. If you are driving around with 7psi in your tires, a map/tps system might be perfectly happy since now the throttle is open wider for a given RPM and VE has increased, but an injector signal would be telling an entirely different story.

I am also biased by the mental trappings of my driving style, either near bsfc or nothing usually, so personally having a hard time seeing the rest of the map get filled in, and I guess you just may be an ecomodder if you cringe at the thought of spending the fuel to fill it in

It is certainly thought provoking though, 'preciate that.

[Julian Edgar]

But I'll buy %80 accuracy overall Julian, that sounds attainable, not sure how useful it is though.

The quote was that FuelSmart is, at an educated guess, about 80 per cent as useful as having a live BSFC indicator. For the vast majority of drivers on the road, that makes FuelSmart very useful indeed.