A thought about the Ecotek 'myth'

Actually it doesent. The idle speed is kept constant, and the air valve does this. Adding extra "ecotec" air just means that to keep idle seed correct the air valve closes fractionally...

The idle mixture only depends on air temp, air pressure (manifold), coolant temp, and the "setting" chosen via a screw on the bulkhead...

But either way the ecotec does nothing.

Right, yes that's what I was on about at the start. Like I said, a rather moot point but I was idling away at work thinking supplementary air devices (of all things) and suddenly thought "hang on, surely an ICV does what the Ecotek wants to do, but can't?" and then found a very long-winded way of asking it.

Still, it gave me something to discuss during the day, although it looks like I've sparked off something about learning three years of physics for nothing (which IMO, three years of physics is pretty useless to anybody except someone who does a further three-five years and even then you wouldn't be a mechanic) and what constitutes a nice noise. Oops. To think, my brother spent ages messing around 'tuning' his Ecotek so that it didn't make that stupid pissy noise - I told him that surely that meant it was no longer doing anything, but now I understand that actually he was just trying to hide his shame.

Still, I didn't know that they'd taken their forum off the EcoTek website. Silence speaks volumes. It seems a shame to make something with spinny bits in it and a complicated explanation actually do nothing. I wonder if the people at the factory are wracked with guilt over it.

Chris.

No, Nom was right. The device only opens (ie lets in air) when there is a very large manifold vacuum. This only occurs when the throttle is closed, or very nearly so. Under these conditions it *reduces* the manifold vacuum, ie increases the manifold absolute pressure.

Well, if I'm pumping in a certain amount of fuel, then I let some extra air in, doesn't that mean that the ratio of fuel to air has changed, hence varying the mix - or does the mix not change as the engine sucks in as much air as it wants? Have I answered my own question and just realised what's behind my confusion? Or are you going to say 'no' again?

;)

Chris.

It makes NO difference at idle because the total air the engine requires to achive the programmed idle rpm is readjusted via the air valve...

Fit 4 ecotecs, and all that will happen is the air valve will close a bit...

My SD1 Rover has a factory fit valve which does this - to weaken the mixture on the over-run, and reduce emissions. Somehow, I doubt anyone would buy such a device if not factory fitted...

Oh dear.

When your foot is on the throttle, you have LESS engine vacuum (because you've just created a bloody big leak in the system !).

You need MORE vacuum in order to force the EcoTek open against it's spring !

See the other replies to your post !

Doh. You're absolutely right.

Indeed.

As a physicist, I would disagree with that :) I think that a 3-year physics course give you a better general grounding in how stuff really works than just about anything else. Of course you still won't be a mechanic, because you don't learn the specifics of any given mechanism.

"Albert T Cone" wrote in message news:Xns951368B06B4DB224267@130.133.1.4...

Yeah, I was making light of it a bit ;) Agreed, learning physics (as I did) gives a fantastic understanding of how things work. The thing that annoyed me was it seemed like every year someone said 'you know last year we said that such and such works because of this and that and blah blah blah? Well, actually it doesn't. Here's how it really works... until next year when we'll make it even more complicated and then eventually tell you that we're not really sure what works' But, I have to say, whilst it does give us a fantastic understanding of everything, it's pretty much useless in the real world. I have never, ever found my knowledge of electron tunnelling useful, you can't impress a woman with Einstien's theory of relativity and I have never needed the instructions given to me by one physics teacher years ago on 'how to make an atomic bomb'. Oh - and don't bring up quantum mechanics at the pub. A mate of mine paid more attention, continued doing nuclear physics at university and is currently working on his PHD. Now he's travelling round the world going to various labs doing weird stuff that no one knows anything about like 'coulexing' stuff, whatever the hell that is. He tells me it's kinda boring but that has gotta be one of the seriously cool jobs that you could do. Here I am trying to understand how bits of car engines work and he's coulexing titanium or something. The git. I wouldn't ask him for help on my car though.

Chris.