Drivetrain Transmission, LSD, Clutch, Driveline, Axles...

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Old 05-24-2008, 02:12 PM
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Originally Posted by EXsoccer1921
okay well your engine has to have fuel to run. period. even if your foot is off the gas it is still being injected with fuel. but very little, just enough to keep it running.
If you say so, lol.
Old 05-24-2008, 02:14 PM
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I'm gonna try driving with the engine off when I get outta work but I assume all you can do is down shift really because obviously you can't accelerate...
Old 05-24-2008, 02:22 PM
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Originally Posted by chris88z24
If you say so, lol.
yes, i do say so. it's simple logic. it's a combustion engine, IT RUNS ON FUEL!!!!!! if no fuel was being injected it would stall and shut off, not keep running.

here try this, put it in first and get up to 5mph, then take your foot off the gas and see how far you go (on level ground). won't get far cause it will stall, cause it will need more fuel to keep going.
Old 05-24-2008, 02:22 PM
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Originally Posted by Chevy Cobalt 08
I'm gonna try driving with the engine off when I get outta work but I assume all you can do is down shift really because obviously you can't accelerate...
Don't do it lol. It's not safe. DO it in an empty parking lot at like 10mph in 1st if you wanna try it out, but PLEASE do NOT do that on a public road.
Old 05-24-2008, 02:23 PM
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you need to start getting your info from somewhere else
Old 05-24-2008, 02:23 PM
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Originally Posted by EXsoccer1921
yes, i do say so. it's simple logic. it's a combustion engine, IT RUNS ON FUEL!!!!!! if no fuel was being injected it would stall and shut off, not keep running.

here try this, put it in first and get up to 5mph, then take your foot off the gas and see how far you go (on level ground). won't get far cause it will stall, cause it will need more fuel to keep going.
But during that period when you let off the throttle, you're using 0 gas until the computer says otherwise (I think around 800 or so RPM the computer gives the engine gas to prevent stalling). Same concept in other gears except it can decelerate longer due to being in a taller gear.

Research it man, **** theres even a few vids on youtube with scan gauges hooked up that prove what I am trying to say.
Old 05-24-2008, 02:25 PM
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i'm done, this is pointlesss. i'm trying to prove to you why the engine is doing exactly what it is made to do. the ignorance of some people is just mind blowing.
Old 05-24-2008, 02:26 PM
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hehe, i always love showing this concept to my friends. downshift and reset your mpg reading. no throttle, just let it slowly go from high rev down.

not only are you keeping rev's up thereby keeping coolant rushing around but you are not creating such strong explosions in the cylinders, thereby cooling the engine AND your not using **** worth of gas. YOU ARE STILL USING GASOLINE! THE CAR IS NOT RUNNING OFF OF COMPRESSION, although the compression DOES help keep the engine going while it still delivers absolute minimal gasoline.

and actually after you start moving if ya clutch in the car while your still maintaining any kinda speed you'll notice the computer does rev up the car to about 1200 rpm's. then ya stop, rpm's lower back to correct idle.
Old 05-24-2008, 02:28 PM
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Originally Posted by EXsoccer1921
i'm done, this is pointlesss. i'm trying to prove to you why the engine is doing exactly what it is made to do. the intelligence of some people is just mind blowing.

fixed.

e-arguing FTW!
Old 05-24-2008, 02:28 PM
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Originally Posted by chris88z24
Don't do it lol. It's not safe. DO it in an empty parking lot at like 10mph in 1st if you wanna try it out, but PLEASE do NOT do that on a public road.
duh lol I'm not stupid... but I can still like downshift with the car off right? (like get the car up to 3rd then turn it off)
Old 05-24-2008, 02:30 PM
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Originally Posted by Chevy Cobalt 08
duh lol I'm not stupid... but I can still like downshift with the car off right? (like get the car up to 3rd then turn it off)
I've never shifted while the car was off so idk.. i've turned it off once and coasted to a stop just to be a jackass once. It's the same as if the key is in the ON position except when you push the clutch in the engine won't stay running, lol.
Old 05-24-2008, 02:32 PM
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Originally Posted by warrenb213
hehe, i always love showing this concept to my friends. downshift and reset your mpg reading. no throttle, just let it slowly go from high rev down.

not only are you keeping rev's up thereby keeping coolant rushing around but you are not creating such strong explosions in the cylinders, thereby cooling the engine AND your not using **** worth of gas. YOU ARE STILL USING GASOLINE! THE CAR IS NOT RUNNING OFF OF COMPRESSION, although the compression DOES help keep the engine going while it still delivers absolute minimal gasoline.

and actually after you start moving if ya clutch in the car while your still maintaining any kinda speed you'll notice the computer does rev up the car to about 1200 rpm's. then ya stop, rpm's lower back to correct idle.
WWOOOOOOOOOOOOOOOOOOOOOOOOOOO finally someone other than me who knows what they're talking about
Old 05-24-2008, 02:35 PM
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The momentum of the car is what keeps the engine "running" actually. Wheels spin = spin axles = spin tranny shaft = spin clutch = spin flywheel = spin crankshaft = engine still turns at X rpm's..
Old 05-24-2008, 02:45 PM
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^^yeah...when it's off. when it's running it needs fuel. no question about it. thats why they call it a combustion engine. doesn't matter if your foot is off the throttle or not, its still being injected with fuel. but when youre off the throttle its only being injected with enough to keep it from stalling.

you can't make the engine run by spinning the wheels, you can make it go through all it's stages but it will not create any power what so ever

Last edited by EXsoccer1921; 05-24-2008 at 02:45 PM. Reason: Automerged Doublepost
Old 05-24-2008, 02:48 PM
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dude your still using gas, although minimal, you are still using gas.

i'd be very curious to see all this data you have showing NO gas consumption in such a scenario.

I'm simply arguing that a very small amount of gas is STILL being used. i can argue this point as if you were completely right with your statement, the mpg reading on the car would increase exponentially. which it does not. i've tried this down hills, and will take a vid of this if needed. either way, the car does not completely cut itself off from gas.
Old 05-24-2008, 02:49 PM
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actually now that I think about it... I don't think it would be a good idea to downshift with the engine off as you can't rev match... question though... why are you able to start a manual with no battery power??
Old 05-24-2008, 03:29 PM
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ok lets say your battery is near death. not enough juice for the starter to torque over the engine. now imagine the accessory/on position as the "primer" as at this point the fuel pump kicks as well as other bells and whistles. with accessory/on set everything about the car is ready to go, just needs the engine in rotation.

just think of the push technique as a way to get the vehicle going if you didn't have a starter(the thing that actually cranks the engine over typically when you switch into ignition). It essentially is the same process as normally starting the car, except your using the momentum of the car to get the first revolutions. as this process occurs the ecu probably still is at an operable power range and provides the engine with everything it normally does. engine gets going, excess power charges the almost dead battery.

chances are if your push starting a car, it's because the battery is simply unable to sustain the amp load the starter requires to crank the engine over. hence why typically in such a situation the door chimes, and lights still work.

in a completely no battery power situation, the start would be a rough one which you hope the first few rpm's will give the alternator enough to actually make a charge and get everything properly going.

Hope this makes enough sense. A lot goes into it, and i figured this would be the easiest way of describing it.
Old 05-24-2008, 03:37 PM
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woah woah woah... okay.

the engine is always using fuel, even at zero throttle, the cylinders ingest a certain amout of fuel per cycle, so gas in injected proportionally. (unless it's a DOD engine). it's not much, but it is some.

now, dieseling is when the heat of the engine allows the car to keep running without the ignition on. this normally happens on a carb engine where the plugs are either gapped wrong, or worn out. on a cobalt, this is damn near impossable, as for it to happen, the car would have to keep the fuel pump on... but it was a real issue on older cars, esp those made with early carb smog controlled cars.

this is just a silly thread, someone lock it.

Originally Posted by warrenb213
ok lets say your battery is near death. not enough juice for the starter to torque over the engine. now imagine the accessory/on position as the "primer" as at this point the fuel pump kicks as well as other bells and whistles. with accessory/on set everything about the car is ready to go, just needs the engine in rotation.

just think of the push technique as a way to get the vehicle going if you didn't have a starter(the thing that actually cranks the engine over typically when you switch into ignition). It essentially is the same process as normally starting the car, except your using the momentum of the car to get the first revolutions. as this process occurs the ecu probably still is at an operable power range and provides the engine with everything it normally does. engine gets going, excess power charges the almost dead battery.

chances are if your push starting a car, it's because the battery is simply unable to sustain the amp load the starter requires to crank the engine over. hence why typically in such a situation the door chimes, and lights still work.

in a completely no battery power situation, the start would be a rough one which you hope the first few rpm's will give the alternator enough to actually make a charge and get everything properly going.

Hope this makes enough sense. A lot goes into it, and i figured this would be the easiest way of describing it.
a cobalt won't do this.

Last edited by joeworkstoohard; 05-24-2008 at 03:37 PM. Reason: Automerged Doublepost
Old 05-24-2008, 03:48 PM
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Originally Posted by joeworkstoohard
this is just a silly thread, someone lock it.
noooo that's ok. I'd like at least ONE of my threads unlocked.... <_<

Originally Posted by joeworkstoohard
a cobalt won't do this.
so I guess we're screwed then in a no-battery situation...

Last edited by chevy cobalt 08; 05-24-2008 at 03:48 PM. Reason: Automerged Doublepost
Old 05-24-2008, 04:44 PM
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i figured the cobalt wouldn't work in a no battery situation. but in the way i described with low battery, it most definitely will.
Old 05-24-2008, 04:48 PM
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Originally Posted by warrenb213
i figured the cobalt wouldn't work in a no battery situation. but in the way i described with low battery, it most definitely will.
if the battery in a balt gets too low, it starts shutting off non essentials, like the AC, ABS, etc, then eventually, it dies. if the battery is bad, and not charging, same thing. you've got about 20 minutes of reserve if you take the alternator out of the formula, but the battery is 100% required.
Old 05-24-2008, 05:45 PM
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hmm the car wouldn't restart when I turned it off I hadda come to a complete stop
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