Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 02-22-2011, 12:10 PM   #181 (permalink)
Smooth Operator
 
Join Date: Feb 2011
Location: dover tn
Posts: 147

Old Yellar - '79 MGB Tourer Drop-Hood Coupé
Sports Cars
90 day: 25.83 mpg (US)

Old Brown Ford - '91 Ford Bronco Custom

MAGNUM - '05 DODGE MAGNUM SXT
Thanks: 9
Thanked 15 Times in 14 Posts
*B*1798CC Power torque & fuelconsumption curves

linkback reference and credit
fair usage

The MG Experience: Library: Power, Torque and Consumption Curves



RPM Torque BHP Fuel Consumption MPH Fuel Consumption fuel consumption
(Lb.Ft.) (Pints BHP/hr) 4th gear [pints/hr] [pints/mile]
1000 71 0.95
1500 89 26 0.78
2000 101 38 0.69 36 26.22 0.728
2500 107 51 0.63 45 32.13 0.714
3000 110 63 0.58 54 36.54 0.676
3500 108 73 0.57 63 41.61 0.660
4000 106 81 0.575 72 46.57 0.647
4500 104 88 0.59 81 51.92 0.641
5000 98 94 0.62 90 58.28 0.648
5500 91 95 0.65
6000 92 0.73
http://www.mgexperience.net/article/...MGBGT_1966.pdf

Attached Thumbnails
Click image for larger version

Name:	fuel-power.jpg
Views:	143
Size:	26.8 KB
ID:	7855   Click image for larger version

Name:	fuelconsumption (Large).jpg
Views:	114
Size:	126.3 KB
ID:	7859  
Attached Files
File Type: txt rpmfuel.txt (800 Bytes, 36 views)

Last edited by MGB=MPG; 02-22-2011 at 03:23 PM..
  Reply With Quote
The Following User Says Thank You to MGB=MPG For This Useful Post:
khafra (06-16-2011)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 02-22-2011, 05:48 PM   #182 (permalink)
EcoModding Lurker
 
Hubert Farnsworth's Avatar
 
Join Date: Feb 2011
Location: USA
Posts: 70

Planet Express Ship - '94 Geo Prizm LSI
90 day: 36.57 mpg (US)
Thanks: 0
Thanked 5 Times in 3 Posts
I know the original topic is a bit old now, but the top curve represented the wide open throttle torque, and each of the islands represents different part open throttle curves shown in contour format which is a way of referencing 3 dimensional data in a simplified two dimensional format.

The BMEP is a function of the work done per cycle divided by the displacement volume of the engine, and is a way of converting power in Kilowatts into the non displacement dependent variable of pressures which in an ideal engine would scale perfectly without regard to displacement.

The reason BMEP and Torque are sometimes interchanged the labled axis of the BSFC charts has to do with the fact that BMEP can be derived from the equation 2*Pi*Torque*Z / Displacement volume (for metric units in N-m for torque, and meters cubed for displacement) (Z=2 for four stroke engines and 1 for 2 stroke engines) BMEP can also be described as normalized torque.

Brake specific fuel consumption is based on the mass flowrate of the fuel divided by the power output of the engine in metric that becomes grams per kilowatt-hr.
  Reply With Quote
The Following 2 Users Say Thank You to Hubert Farnsworth For This Useful Post:
khafra (06-16-2011), TEiN (02-22-2011)
Old 03-28-2011, 12:46 PM   #183 (permalink)
EcoModding Lurker
 
Join Date: Mar 2011
Location: Illinois
Posts: 23
Thanks: 0
Thanked 7 Times in 2 Posts
Am i right to say that one should open the throttle over a period of 2 second, instead of an instantaneous "blip", as I understand a blip (opening in less than 1 second/or high pedal angular velocity) also causes fuel enrichment for the duration of the blip.

It would be nice if the % throttle opening values could be mapped to % depression of the accelerator pedal, as I understand many manufacturer don't use a linear relationship (in drive by wire) of accelerator pedal depression vs throttle opening. i.e. a 20% pedal depression may equate to 40% throttle opening. This may be done so that the car appears more powerful to an unsuspecting customer.

Just me 2 cents.
  Reply With Quote
Old 05-26-2011, 03:33 AM   #184 (permalink)
RRC
EcoModding Lurker
 
RRC's Avatar
 
Join Date: Apr 2011
Location: PL
Posts: 24

Skodillac - '97 Skoda Felicia Hatch. MPI
TEAM VW AUDI Group
90 day: 41.98 mpg (US)

Toyota YS - '20 - -
Team Toyota
90 day: 59.89 mpg (US)
Thanks: 6
Thanked 0 Times in 0 Posts
Skoda Felicia 1.3 MPI engine 50kW (68HP)

Here is a power/torque/bsfc chart for Skoda Felicia with 1.3 MPI engine:



Click on it to resize
Click image for larger version

Name:	bsfc_felicia_mpi_.jpg
Views:	1374
Size:	19.9 KB
ID:	8463

Last edited by RRC; 05-26-2011 at 04:00 AM..
  Reply With Quote
Old 06-26-2011, 02:51 PM   #185 (permalink)
EcoModding Apprentice
 
Join Date: Oct 2008
Location: Chile
Posts: 223

Mercedes 89 D - '89 Mercedes 300 E
90 day: 33.86 mpg (US)

Skodie - '09 Skoda Octavia TDI PD
90 day: 38.84 mpg (US)

1993 Mercedes 300D Turbo - '93 Mercedes Benz 300D Turbo W124
90 day: 26.19 mpg (US)

Crossie - '16 Subaru XV Crosstreak
90 day: 9.61 mpg (US)

Crossie - '16 Subaru XV Crosstreak
90 day: 33.34 mpg (US)
Thanks: 15
Thanked 9 Times in 7 Posts
BSFC charts: what is that?

Hello, these chart must be very useful, I guess. Can you please give us all a small intro to understand what are they and what is their importance?

Tks a lot for yr contribution.
__________________
Mercedes 300 D turbo 1993
  Reply With Quote
Old 06-26-2011, 06:41 PM   #186 (permalink)
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 843

17 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

Blue Bob's - '19 Tesla Std Rng Plus
Thanks: 94
Thanked 246 Times in 157 Posts
Quote:
Originally Posted by oldbeaver View Post
Hello, these chart must be very useful, I guess. Can you please give us all a small intro to understand what are they and what is their importance?
I will share my understanding in the hope that others may provide more details.

The Brake Specific Fuel Consumption measures how much power is provided versus fuel consumption of an engine in a test stand with the throttle wide open. The engine rpm is controlled by how much resistive force is applied. There are no accessory loads, not even water pump. It is a map of the best-case engine performance.

This chart can be used to find the optimum, rpm-power bands. In theory and practice, one could drive to stay in the peak efficiency band and maximize fuel economy. But a lucky few can do in-car measurements.

To do an in-car measurement, one needs:
  • engine torque
  • engine rpm
  • fuel consumption
Usually torque is the problem but a few cars have them.

The product of engine torque and rpm is the power. Fuel consumption can be measured by mass air flow (14.7 to 1 air to fuel ratio) or fuel injector timing adjusted for the 'dead time.'

Once the data is collected and plotted, we can find inflection points, the knee or sometimes curve in the graph that identifies the optimum engine operating range(s). For example:
  • 0-<980 - engine off, hybrid mode, very good
  • 980-1200 - engine idle during warm-up, avoid
  • 1200-2400 - good place to be
  • 2400-3200 - mileage starts to decline
  • 3200-4150 - owch
  • 4150-4500 - do not go there
These are specific to the 1.5L, NHW11 model Prius.

Bob Wilson
__________________
2019 Tesla Model 3 Std. Range Plus - 215 mi EV
2017 BMW i3-REx - 106 mi EV, 88 mi mid-grade
Retired engineer, Huntsville, AL
  Reply With Quote
Old 06-26-2011, 07:01 PM   #187 (permalink)
dcb
needs more cowbell
 
dcb's Avatar
 
Join Date: Feb 2008
Location: ˙
Posts: 5,038

pimp mobile - '81 suzuki gs 250 t
90 day: 96.29 mpg (US)

schnitzel - '01 Volkswagen Golf TDI
90 day: 53.56 mpg (US)
Thanks: 158
Thanked 269 Times in 212 Posts
Quote:
Originally Posted by bwilson4web View Post
...
The Brake Specific Fuel Consumption measures how much power is provided versus fuel consumption of an engine in a test stand with the throttle wide open
Let me chime in here, I think they have to be using several throttle settings in order to create the "isobars" on the good bsfc maps, otherwise the load would be fixed at 100% for any given RPM and there would not be any data for consumption at less than 100% load.
__________________
WINDMILLS DO NOT WORK THAT WAY!!!
  Reply With Quote
Old 06-26-2011, 11:28 PM   #188 (permalink)
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 843

17 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

Blue Bob's - '19 Tesla Std Rng Plus
Thanks: 94
Thanked 246 Times in 157 Posts
I don't know how the islands, the areas, of specific fuel consumption are plotted but it makes sense there is some throttle operation. In my case, plotting BSFC along the operating line provides a useful guide. Here is one of the better articles about BSFC:

Brake Specific Fuel Consumption

As Julian Edgar points out in the article, partial throttle operation significantly reduces engine efficiency. So it makes sense partial throttle operation is used to map the inefficient parts of the chart.

Bob Wilson
__________________
2019 Tesla Model 3 Std. Range Plus - 215 mi EV
2017 BMW i3-REx - 106 mi EV, 88 mi mid-grade
Retired engineer, Huntsville, AL

Last edited by bwilson4web; 06-26-2011 at 11:47 PM..
  Reply With Quote
Old 06-27-2011, 04:18 PM   #189 (permalink)
Master EcoModder
 
Join Date: Jul 2008
Location: Silly-Con Valley
Posts: 1,479
Thanks: 201
Thanked 262 Times in 199 Posts
You can think of these plots as 3-D plots. You have load (or torque, both of which are to a great extent determined by throttle position) on the vertical axis, RPM on the horizontal axis, and fuel consumption on the axis that comes out of the screen. The plot is like a contour map of those three things.

-soD
  Reply With Quote
Old 06-27-2011, 09:59 PM   #190 (permalink)
Pokémoderator
 
cfg83's Avatar
 
Join Date: Dec 2007
Location: Southern California
Posts: 5,864

1999 Saturn SW2 - '99 Saturn SW2 Wagon
Team Saturn
90 day: 40.49 mpg (US)
Thanks: 439
Thanked 530 Times in 356 Posts
some_other_dave -

Quote:
Originally Posted by some_other_dave View Post
You can think of these plots as 3-D plots. You have load (or torque, both of which are to a great extent determined by throttle position) on the vertical axis, RPM on the horizontal axis, and fuel consumption on the axis that comes out of the screen. The plot is like a contour map of those three things.

-soD
That's what I thought. In dcb's plot we speculated that WOT was the continous line at the top connected by the black dots :



CarloSW2

__________________

What's your EPA MPG? Go Here and find out!
American Solar Energy Society
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com