Backup trick - NHW11
#1
Backup trick - NHW11
Hi,
So far, my experiments show this works with the NHW11. It may also work with the NHW20. However, it is a little "exciting" the first few times and somewhat risky if you are not practiced.
PROBLEM
Until the coolant reaches 70 C, the engine of the NHW11 runs regardless. If you are stopped at a light or stop sign due to traffic, the idling engine can make a significant impact on your mileage. However, turning off the car induces a second, more wasteful engine STOP/START cycle.
SOLUTION
NOTE: be sure to practice this with no other traffic around!
NOTE 2: it seems to work only with the coolant below 40C
This works because the NHW11 turns off the engine when going in reverse. However, it appears you only have to be in "R" and hit the accelerator. It doesn't notice that the car is being held stationary by the power front disk brakes. So pulsing the accelerator causes it to shutdown the ICE. Then you slip into "N" to keep it from restarting the ICE.
Now this process can be a little exciting and the steps have to be follow precisely. It is especially important that the left foot hold the brake HARD as backing into a car behind you will result in further delays. However, it seems to work. This may also work with the NHW20 but I do not have a test vehicle.
Subsequent testing indicates that shutting off the engine is a brief event. When the coolant temperature is under 40C, it works reliably. However, above 40C, there is brief pause and the engine continues to run. Still, when the engine is very cool, anytime it can be shutdown at a stop is a good thing.
Bob Wilson
So far, my experiments show this works with the NHW11. It may also work with the NHW20. However, it is a little "exciting" the first few times and somewhat risky if you are not practiced.
PROBLEM
Until the coolant reaches 70 C, the engine of the NHW11 runs regardless. If you are stopped at a light or stop sign due to traffic, the idling engine can make a significant impact on your mileage. However, turning off the car induces a second, more wasteful engine STOP/START cycle.
SOLUTION
NOTE: be sure to practice this with no other traffic around!
NOTE 2: it seems to work only with the coolant below 40C
- Hold the foot brake with your left foot, hard!
- Shift into "R".
- Pulse the accelerator. --> engine stops
- Shift into "N".
- Use right foot to hold brake, normally
- When light changes, shift into "D", release brake, and drive off
This works because the NHW11 turns off the engine when going in reverse. However, it appears you only have to be in "R" and hit the accelerator. It doesn't notice that the car is being held stationary by the power front disk brakes. So pulsing the accelerator causes it to shutdown the ICE. Then you slip into "N" to keep it from restarting the ICE.
Now this process can be a little exciting and the steps have to be follow precisely. It is especially important that the left foot hold the brake HARD as backing into a car behind you will result in further delays. However, it seems to work. This may also work with the NHW20 but I do not have a test vehicle.
Subsequent testing indicates that shutting off the engine is a brief event. When the coolant temperature is under 40C, it works reliably. However, above 40C, there is brief pause and the engine continues to run. Still, when the engine is very cool, anytime it can be shutdown at a stop is a good thing.
Bob Wilson
Last edited by bwilson4web; 12-18-2008 at 12:24 AM.
#2
Re: Backup trick - NHW11
Bob,
doesn't your complicated/convoluted technique result in just as many WASTEFUL stop and start engine cycles as would be the case in simply "turning off" the car..??
And with no "danger" in the "turning off" case...??
doesn't your complicated/convoluted technique result in just as many WASTEFUL stop and start engine cycles as would be the case in simply "turning off" the car..??
And with no "danger" in the "turning off" case...??
#3
Re: Backup trick - NHW11
- hit "start" on key, all ECUs have to come up
- MG1 spins ICE for 2-3 seconds
- apply gas, ignition and wait for ICE response
- shift "D", all ECUs are already up
- MG1 spins ICE and uses a faster, ~250 ms., power up
- apply gas and ICE responds
Bob Wilson
#4
Re: Backup trick - NHW11
Bob,
When I first read the title, I was expecting to read that your new method was to drive to work in reverse during rush hour in Huntsville.... That would have been exciting to watch.
When I first read the title, I was expecting to read that your new method was to drive to work in reverse during rush hour in Huntsville.... That would have been exciting to watch.
#5
Re: Backup trick - NHW11
Hi,
So far, my experiments show this works with the NHW11. It may also work with the NHW20. However, it is a little "exciting" the first few times and somewhat risky if you are not practiced.
PROBLEM
Until the coolant reaches 70 C, the engine of the NHW11 runs regardless. If you are stopped at a light or stop sign due to traffic, the idling engine can make a significant impact on your mileage. However, turning off the car induces a second, more wasteful engine STOP/START cycle.
SOLUTION
NOTE: be sure to practice this with no other traffic around!
This works because the NHW11 turns off the engine when going in reverse. However, it appears you only have to be in "R" and hit the accelerator. It doesn't notice that the car is being held stationary by the power front disk brakes. So pulsing the accelerator causes it to shutdown the ICE. Then you slip into "N" to keep it from restarting the ICE.
Now this process can be a little exciting and the steps have to be follow precisely. It is especially important that the left foot hold the brake HARD as backing into a car behind you will result in further delays. However, it seems to work. This may also work with the NHW20 but I do not have a test vehicle.
Bob Wilson
So far, my experiments show this works with the NHW11. It may also work with the NHW20. However, it is a little "exciting" the first few times and somewhat risky if you are not practiced.
PROBLEM
Until the coolant reaches 70 C, the engine of the NHW11 runs regardless. If you are stopped at a light or stop sign due to traffic, the idling engine can make a significant impact on your mileage. However, turning off the car induces a second, more wasteful engine STOP/START cycle.
SOLUTION
NOTE: be sure to practice this with no other traffic around!
- Hold the foot brake with your left foot, hard!
- Shift into "R".
- Pulse the accelerator. --> engine stops
- Shift into "N".
- Use right foot to hold brake, normally
- When light changes, shift into "D", release brake, and drive off
This works because the NHW11 turns off the engine when going in reverse. However, it appears you only have to be in "R" and hit the accelerator. It doesn't notice that the car is being held stationary by the power front disk brakes. So pulsing the accelerator causes it to shutdown the ICE. Then you slip into "N" to keep it from restarting the ICE.
Now this process can be a little exciting and the steps have to be follow precisely. It is especially important that the left foot hold the brake HARD as backing into a car behind you will result in further delays. However, it seems to work. This may also work with the NHW20 but I do not have a test vehicle.
Bob Wilson
#6
Re: Backup trick - NHW11
It is a more efficient start/stop compared to the manual method:
You're assuming ECU shutdown (along with lights/accessories..?) during "off".
ADVANTAGE, overall
But if so that would be pretty **** poor programming. Most engines can be started under computer control within a minimum of 630 degrees of rotation, one of the major advantages of "E-start", you don't determine how long the starter is/remains engaged, the ECU does that.
Okay, under your technique, the light goes "green", YOU shift out of reverse, THEN, ONLY then, lift your foot from the brake, move your foot to the gas pedal and apply pressure. Now you wait to go forward after the engine restarts.
With the "N" trick:
A restart, or initial start, must turn the ICE over long enough for at least one cylinder to ingest an air charge, AFTER reaching an EFI injection time/period, and then, via a compression cycle, fire the ignition.
630 degrees, minimum, of crank rotation for a start.
"My data suggests.."
Does NOT compute....
Bob Wilson
- hit "start" on key, all ECUs have to come up
You're assuming ECU shutdown (along with lights/accessories..?) during "off".
ADVANTAGE, overall
- MG1 spins ICE for 2-3 seconds
But if so that would be pretty **** poor programming. Most engines can be started under computer control within a minimum of 630 degrees of rotation, one of the major advantages of "E-start", you don't determine how long the starter is/remains engaged, the ECU does that.
- apply gas, ignition and wait for ICE response
Okay, under your technique, the light goes "green", YOU shift out of reverse, THEN, ONLY then, lift your foot from the brake, move your foot to the gas pedal and apply pressure. Now you wait to go forward after the engine restarts.
With the "N" trick:
- shift "D", all ECUs are already up
- MG1 spins ICE and uses a faster, ~250 ms., power up
A restart, or initial start, must turn the ICE over long enough for at least one cylinder to ingest an air charge, AFTER reaching an EFI injection time/period, and then, via a compression cycle, fire the ignition.
630 degrees, minimum, of crank rotation for a start.
- apply gas and ICE responds
"My data suggests.."
Does NOT compute....
Bob Wilson
Is there a chance that your data is flawed because MPG computation is suspended in reverse due to "forward proess" not being possible...??
Last edited by wwest; 12-11-2008 at 10:27 AM.
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