Holden Engine Efficiency

[VR38]

The BMEP is based around design efficiency, not fuel efficiency.

I can't see it, take the buick V6 for example, bump the compression ratio up and up go the numbers.

Same with the cam, put a bigger cam in it to raise the redline (we are not changing the design of the motor) and up go the figures.

 

[AirStrike]

Mine works out to be 30.

 

[VR38]

Same with the boosted motors, how are you comparing design efficiency when all you have to do is wind more boost in, up go the numbers.

 

[Kiddo]

Same with the boosted motors, how are you comparing design efficiency when all you have to do is wind more boost in, up go the numbers.

If the engine can take it without blowing up, then its fair enough.

Also, if you start modifying it, you are changing the design to a different one. Still valid.

 

[monkeys437]

It's just a comparative measure of how efficiently an engine converts pressure into torque by the looks of it. From memory, turbocharged and supercharged engines have different ways of calculating MEP to NA engines so I'm not sure if the same formula should be used for both? It's been a while since I've studied this stuff though so I could be miles off the mark lol

 

[PIR4TE]

Brake Specific Fuel Consumption is the key measure of fuel / power efficiency, overcoming the flaws of MEP calc outlined above (being one facet of design efficiency), and the paradox of specific hp/displacement in the case of forced induction / wankel / two stroke piston / turboprop etc.
A stock VE 6.0 is 0.47 (less is better).
http://www.land-and-sea.com/dyno-tech-talk/using_bsfc.htm

 

[AirStrike]

How does the average joe find out their hourly fuel consumption at full noise?

 

[PIR4TE]

Not easily without OBD scanner, dyno or at least a dyno chart... and ideally the rated fuel flow of your injectors to crosscheck, but that can be estimated.
For example to achieve the rwkw as per your dyno, your injectors must have a static fuel rating of 880cc, 80% duty - 84 lb/hr. Dunno what spec exactly, but more specific info means more accurate BSFC without scanner or dyno.

 

[ari666]

do you speak this much **** in real life too?

 

[PIR4TE]

Thanks, very helpful, I bet all members are glad to hear your comments, off-topic, on-par with the crap you are copping in other threads for piping up with half baked wise cracks and generally being out of line.
What do you have to contribute to the OP Mr Superhelpfulness?