|
|
|
|
Thread Tools | Display Modes |
08-28-2013, 09:59 PM | #226 | |
Scooby Specialist
Member#: 319157
Join Date: May 2012
Chapter/Region:
MAIC
Vehicle:2012 Impreza 4DR 5MT |
Quote:
I'm very familiar with ECU operation. The engine is not just a power source, it's a load and it requires more power to spin itself at higher RPMs. Notice your car takes more throttle to free rev at higher RPMs. Free revving is the point where internal engine losses equal the energy produced by the engine, since no power is taken off the crankshaft (except through accessories). Producing useful power at 4K RPM requires more fuel than to free rev at 4K RPM. However, the same fuel required to free rev at 4K RPM can produce plenty of useful output power at 1500 RPM.
* Registered users of the site do not see these ads.
|
|
08-28-2013, 10:33 PM | #227 | |
Scooby Specialist
Member#: 354284
Join Date: Apr 2013
Location: Midwest
Vehicle:2013 Imp Sport CVT SWP |
Quote:
|
|
08-28-2013, 11:14 PM | #228 | |
Scooby Specialist
Member#: 319157
Join Date: May 2012
Chapter/Region:
MAIC
Vehicle:2012 Impreza 4DR 5MT |
Quote:
|
|
08-29-2013, 12:05 AM | #229 | |
Scooby Specialist
Member#: 354284
Join Date: Apr 2013
Location: Midwest
Vehicle:2013 Imp Sport CVT SWP |
Quote:
What you said is correct all but the first part of the first sentence. I suppose the tach isn't connected to the injectors, so maybe from that standpoint your right. But it takes increasing intake cycles ( thus engine cycles thus engine revolutions which is RPM'S) to increase the duty cycles. This is actually the way you would properly size your injectors. If the duty cycles are 85-90% or more you should look at increasing your injectors size. I think we are somewhat talking about the same thing, however seems like a tangent. We started off talking about mpg's. |
|
08-29-2013, 06:09 AM | #230 | |
Scooby Specialist
Member#: 299286
Join Date: Oct 2011
Chapter/Region:
NESIC
Location: Upstate NY
Vehicle:2017 Legacy Limited White |
Quote:
Either the CVT gets better HWY mpg's than the 5 Speed, or it doesn't (evidence from multiple sources say it does, though individuals unhappy with their personal mpg's surmise it does not) Either the higher HWY mpg's is due to the engine turning lower rpm at highway speeds, or it isn't (still trying to figure out why people are arguing RPM is irrelevant. They seem to think having a lower RPM at highways speeds is a curse, because it requires the car to "downshift", which they then presume means is raises the RPM way higher than a 5 Speed turns, in 5th or 4th -- or others just argue that RPM is unrelated to mpgs) Either there is more drivetrain/transmission drag from a CVT or from a 5 Speed. Since this isn't measurable, opinions vary. So which is it, do CVT's suck, or are they better at delivering better MPG's on the highway? |
|
08-29-2013, 07:17 AM | #231 |
Scooby Specialist
Member#: 301213
Join Date: Nov 2011
Chapter/Region:
South East
Location: Raleigh, NC
Vehicle:2012 Imp. Sp. Ltd. Blue/Silver |
|
08-29-2013, 08:17 AM | #232 |
Scooby Specialist
Member#: 354284
Join Date: Apr 2013
Location: Midwest
Vehicle:2013 Imp Sport CVT SWP |
|
08-29-2013, 11:37 AM | #233 | ||
Scooby Specialist
Member#: 319157
Join Date: May 2012
Chapter/Region:
MAIC
Vehicle:2012 Impreza 4DR 5MT |
Quote:
Quote:
Last edited by Commander Keen; 08-29-2013 at 11:51 AM. |
||
08-29-2013, 01:42 PM | #234 | |
Scooby Specialist
Member#: 354284
Join Date: Apr 2013
Location: Midwest
Vehicle:2013 Imp Sport CVT SWP |
Quote:
|
|
08-29-2013, 05:06 PM | #235 | |
Scooby Specialist
Member#: 319157
Join Date: May 2012
Chapter/Region:
MAIC
Vehicle:2012 Impreza 4DR 5MT |
On-time is the amount of time it's on for that cycle. By knowing any two of duty cycle, RPM and on-time, you can calculate the third.
This was your original statement: Quote:
Fuel rate is proportional to duty cycle, not pulse width. You can have relatively long pulse widths at low RPMs without consuming large amounts of fuel. |
|
08-29-2013, 06:50 PM | #236 | |
Scooby Specialist
Member#: 354284
Join Date: Apr 2013
Location: Midwest
Vehicle:2013 Imp Sport CVT SWP |
Quote:
Last edited by G2Spfld; 08-29-2013 at 08:19 PM. |
|
Thread Tools | |
Display Modes | |
|
|