Welcome to the IHoP

[ANeonRider 3]

And starters are more expensive than $10.

No fuel is needed to keep momentum until the revs are around idle. The engine will continue to move on its own without fuel.

ok, going by this thought process, when coasting (in neutral) the engine is simply spinning by momentum, until i press the gas and then it "restarts"? i can't believe this. teh rpms stay a constant amount, around 750, if it was strictly momentum they would go down. they would have too due to drag, both internally and parasitic (accessory drive belts).you simply can't get around those two objects and they will defeat momentum. so there as to be some fuel going into the engine to keep rpms at the set idle.

and in old cars especially. i mean there was an idle screw on that carb for a reason, no?

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

We were talking about engine braking. Like going down a hill in 3rd gear at 3k rpm. The injector load would be @ 0%. The gravitational constant, minus friction, minus parasitic loss etc, the engine would be kept at an rpm ABOVE idle due to gravity and momentum. Once the rpm's dip down close to idle, the injectors would start the combustion process again, keeping the engine at/slightly above idle.

Same principle applies when slowing down using the engine on any surface grade, not the brakes (open loop mode). In neutral, this does not happen, only in gear, above idle speed. Once the revs cross that point of needing fuel to maintain operation, the injectors turn on & the PCM returns to closed loop mode.

[audio-neon 34]

next year:

kent vs chuck norris!

i'd win. i'm bringing a gun..lol...

audio-neon...see what happens when one jumps into the middle of a conversation without reading all of it? i flat put my foot in my mouth and will respectfully back out of the conversation now, lol. sorry.

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

I wasn't trying to confront you. I was more or less giving you the cliff-notes of what we were talking about.

[todd.brust 29]

so bored....waiting while mini-g waxes her box.

part of me wants to bust in with her digicam that's sitting next to me

I say why not?

x2!

NOW!

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

LOL

What kind of waxing do we have going on anyways?

[audio-neon 34]

I feel bad for mini-g's box. But it's less painful than plucking them out 1by1

[mrray13 30]

next year:

kent vs chuck norris!

i'd win. i'm bringing a gun..lol...

audio-neon...see what happens when one jumps into the middle of a conversation without reading all of it? i flat put my foot in my mouth and will respectfully back out of the conversation now, lol. sorry.

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

I wasn't trying to confront you. I was more or less giving you the cliff-notes of what we were talking about.

i know. i was just saying that i'm an idiot for not reading the whole conversation, and then trying to make a point which had nothing to do with the conversation. it's my bad, lol. i appreciate the cliff notes, they are what pulled my head outa my ass, lol

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

[mrray13 30]

no pix of box waxing is grounds for bannage.....especially oriental box.

lol

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

[vladd 26]

opportunity is gone...

peace out hop

[ANeonRider 3]

here is an explanation of open/closed loop as well:

So wtf is closed and open loop? 'Closed Loop' is the term given to the ECU behaviour when the oxygen sensor signal is being used to largely control how much fuel the injectors are adding to the intake. The ECU works in closed loop most of the time - when the car is warmed up and idling, in constant throttle cruise - and so on. The ECU watches the oxygen sensor output and if the mixtures are getting a bit rich, it leans them off. If the mixtures are getting a bit lean, it richens them up. This causes the mixtures to fluctuate rapidly around 14.7:1 air/fuel ratio - what's called the stoichiometric ratio. The ECU aims to keep the mixtures at this number because its there where the cat converter works best at cleaning up the exhaust.

However, an air/fuel of 14.7 doesn't give the best power, so when you put your foot down, the ECU forgets about closed loop and goes instead into an operating system called 'Open Loop'. This just means that it ignores the output of the oxy sensor, instead picking the right amounts of fuel from its internal memories. Typically, the air/fuel ratio outside of closed loop might jump to 13:1, then 12:1 and then even richer still at 10 or 11:1.

The final typical operating approach is when the injectors are stopped completely - yes, they're actually switched off sometimes even when the car is driving along! This happens on the over-run - you're travelling along at 100 km/h, reach an 80 km/h sign and lift your foot. The ECU will then turn off the injectors until either you reapply the accelerator or the engine speed drops to near idle revs.

Like all things, these ideas apply to most cars - not all. Some Porsches, for example, stay in closed loop all the time - even when the mixtures are richer than 14.7:1. In other words, the oxygen sensor (a special one) is used to give mixture feedback to the ECU is all operating conditions. Other cars have a 'lean cruise' system, where on the open highway the mixtures will gradually lean out to say 15 or 16:1, so saving fuel. But for most cars on the road, the above approach is used.

The system will stay in 'Open Loop' until the following conditions are met:

1. The O2 sensor has varying voltage output, showing that it is hot enough to operate properly. (This depends on temperature)

2. The coolant sensor is above a specified temperature about 40oC/104oF.

3. A specific amount of time has elapsed after starting the engine.

The specific values for the above conditions vary with different engines and are stored in the mem-cal. When these conditions are met, the system goes into 'Closed Loop' operation. In 'Closed Loop', the ECM will calculate the air/fuel ratio (injector on-time) based on the various sensors but mainly the O2 sensor. This allows the air/fuel ratio to stay very close to 14.7:1.

[MKader17 332]

i want to build the ZDT3.5s but my room next year is going to be small. I think i'll build them anyway, i can deal with the issues until i move in to my own place.

I feel ya. I want those as well but don't know if I have the funds. I really need to work on the Horn/10" setup for my buds house for parties and rock band instead. The BIB's just can't handle the drum line at higher voumes. I'm real cluless though on Horns.

[Penguin4x4 1,761]

fdfjdslkjfdlskjfdlajflkfji4u5g2p376

[MKader17 332]

.... But for most cars on the road, the above approach is used...

Except for American V8's. Injectors are used at 100%, 100% of the time. Its just the american way

[Tmax98 3]

lol

mk get ur ass to bed lol

[topgun 262]

Tornado Warning for my area right here, chillin in the basement on teh laptop, debating on playing Call of Duty 4...

[Tmax98 3]

that sucks man good luck

[topgun 262]

Hmmm, tornado heading this way apparently. Was standing on the porch and it was nice and calm, then the wind picked up and started raining and sounded like a freight train in the distance for a little bit, kinda went away and I decided to head back downstairs.

[topgun 262]

Apparently it just hit campus... Hmmm....

We are 4 blocks west of campus.

[topgun 262]

It is moving north east so I do believe it will miss us.

[topgun 262]

Well, it has passed it appears.

[Acidburn 10]

Can't say that I would coast in neutral in a vehicle for any extended period of time. To my knowledge the transmission fluid pump is driven off of the input side not that tail shaft so I would think that if you did that you might not get enough fluid pumped through the tranny and could shorten the life of it. Also you run the risk of accidentally slipping it up into reverse and fucking things up. Sure you may be careful 99% of the time on that one, but is saving a little bit of money on fuel really worth the extra risk on fragging the transmission? Now on the new fully electronic controlled ones, I don't know if it will even try to slip into reverse while going that speed.

I've talked to my transmission rebuilder friend about the coasting in N in an auto, and he says that the pump will still provide enough fluid/pressure to get keep things ok in a coasting type situation.

On every car I've ever driven, you had to push the button in to shift into R from N so it's not like it could just slip.

[topgun 262]

Maybe its just all the worn out vehicles I've driven that it is pretty easy to go from neutral to reverse.

[Acidburn 10]

Can't say that I would coast in neutral in a vehicle for any extended period of time. To my knowledge the transmission fluid pump is driven off of the input side not that tail shaft so I would think that if you did that you might not get enough fluid pumped through the tranny and could shorten the life of it. Also you run the risk of accidentally slipping it up into reverse and fucking things up. Sure you may be careful 99% of the time on that one, but is saving a little bit of money on fuel really worth the extra risk on fragging the transmission? Now on the new fully electronic controlled ones, I don't know if it will even try to slip into reverse while going that speed.

I engine brake, coasting is hard on brakes. Engine breaking also shuts off the injectors.

Throwing it into Neutral will remove all ability to accelerate in emergency situations.

I was about to post about the accelerate in emergency, and the brakes issue. But was wondering if anyone else would add their .02$

I don't think the brakes are at all an issue. Automatic cars do just fine stopping without going through brake pads all the time. And engine braking just causes more wear on the clutch, which is definitely more expensive to replace than pads.

[Acidburn 10]

so bored....waiting while mini-g waxes her box.

part of me wants to bust in with her digicam that's sitting next to me

[topgun 262]

Can't say that I would coast in neutral in a vehicle for any extended period of time. To my knowledge the transmission fluid pump is driven off of the input side not that tail shaft so I would think that if you did that you might not get enough fluid pumped through the tranny and could shorten the life of it. Also you run the risk of accidentally slipping it up into reverse and fucking things up. Sure you may be careful 99% of the time on that one, but is saving a little bit of money on fuel really worth the extra risk on fragging the transmission? Now on the new fully electronic controlled ones, I don't know if it will even try to slip into reverse while going that speed.

I engine brake, coasting is hard on brakes. Engine breaking also shuts off the injectors.

Throwing it into Neutral will remove all ability to accelerate in emergency situations.

I was about to post about the accelerate in emergency, and the brakes issue. But was wondering if anyone else would add their .02$

I don't think the brakes are at all an issue. Automatic cars do just fine stopping without going through brake pads all the time. And engine braking just causes more wear on the clutch, which is definitely more expensive to replace than pads.

If the clutch doesn't slip, would it wear more than just regular driving? Coasting would be fine on brakes as long as you don't try it in hilly country. If you try that in mountains or anything you are going to be in a world of hurt.

[Acidburn 10]

Can't say that I would coast in neutral in a vehicle for any extended period of time. To my knowledge the transmission fluid pump is driven off of the input side not that tail shaft so I would think that if you did that you might not get enough fluid pumped through the tranny and could shorten the life of it. Also you run the risk of accidentally slipping it up into reverse and fucking things up. Sure you may be careful 99% of the time on that one, but is saving a little bit of money on fuel really worth the extra risk on fragging the transmission? Now on the new fully electronic controlled ones, I don't know if it will even try to slip into reverse while going that speed.

I engine brake, coasting is hard on brakes. Engine breaking also shuts off the injectors.

Throwing it into Neutral will remove all ability to accelerate in emergency situations.

I was about to post about the accelerate in emergency, and the brakes issue. But was wondering if anyone else would add their .02$

I don't think the brakes are at all an issue. Automatic cars do just fine stopping without going through brake pads all the time. And engine braking just causes more wear on the clutch, which is definitely more expensive to replace than pads.

If the clutch doesn't slip, would it wear more than just regular driving? Coasting would be fine on brakes as long as you don't try it in hilly country. If you try that in mountains or anything you are going to be in a world of hurt.

Each time the clutch engages, there's at least a split second where it's "grabbing" so if you use it to engine brake as well, that's another XX times it's going to "grab".

I guess I'm just too used to driving in the very flat Phoenix valley.

[topgun 262]

To me coasting in neutral is a horrible practice to learn, if you ever drive a semi or big truck you HAVE to use engine braking otherwise your fucked.