Turbo Diesel's unaffected by altitude (proof provided)

[Green1]

Please reread my last post, and ensure your brain is in gear before you pop the clutch for your typing fingers.
Jason

I could say exactly the same thing.

You have yet to answer the basic questions:
1) at what altitude does the magic 100% compensation stop?
2) why do many turbo diesels have altitude compensation if they aren't affected by altitude?
3) why do the most reputable mechanics on the site do this modification? (keeping in mind it has solved several people's problems)
4) why would a delica would work fine at sea level and start smoking when it got to altitude?

Your "proof" contradicts you, it says altitude DOES matter.

[FalcoColumbarius]

Pardon me if I take Mardy, Butch, Edwin, and several thousand diesel engineers working at mercedes and other diesel engine manufacturers over the past century as more reliable sources than one anecdotal description on a single trip.

You're right, Marty had nothing to do with this one. It was just me, Butch, Edwin & Delicat (the Pogi Club). I never reset the boost, it was as she had arrived in the country. I got a mate who used to work on turbos on gasoline engines in the Canadian Army. He felt that between diesels and gasoline the turbos were the same and that tuning the boost above eight PSI would work against the engine as although the turbo would spin faster; it would collect less air for the cylinder, due to the excessive speed. His view is that the sweet spot would be eight PSI and if you wanted to run at 16 PSI ~ get a twin turbo at eight PSI apiece. As I have never really had power issues, I decided to leave it for the time being. So all being said and done you appear to be arguing with Butch, Edwin, my mate Mitch (from the army) & and the engineers of Mitsubishi Motors Corporation, Japan.

Falco.

P.S.: Although I don't always agree with you, Green1, I often do. I always respect your input ~ not that there would be any question about this ~ just to keep the record straight.

[fexlboi]

I'm wondering what the heck thousands Mitsubishi Diesel engineers over the last century were thinking not to put in an altitude compensator on their turbo diesel engines? Either they wanted to produce cars just to operate at sea level or they didn't realize that their home country is one big bloody high mountain range in the middle of the ocean.
Now I know why you have a tool kit in the back. To adjust the IP every few hours, if you want to go up a mountain.

[Green1]

So all being said and done you appear to be arguing with Butch, Edwin,

Considering that they have adjusted more than one Delica specifically for high altitude, I'm not arguing with them, they realize the importance of this adjustment.
As for mitsubishi... considering that Japan is an island nation with most of it's population living at low altitudes, the decision not to bother with altitude compensation makes sense, had they been designing a vehicle for north america I have no doubt they would have included it. (The absence of automatic adjustment does not prove that it is not affected by altitude, only that they didn't think there was a need to account for it automatically)

Nowhere have I ever stated that you need to constantly adjust for this.
I just stated that if your vehicle works fine at sea level, and you drive to altitude and it starts smoking and looses power, there is a simple explanation for it, and it's easily fixable.
A bit of extra smoke and a small power loss will not matter to someone who is just driving through, but for someone who lives at altitude it's worth adjusting.

[Manitoba deli]

Here we go for green1 again

1) you can't get your deli high enough for that to matter.
2) Idle emmisions
3) cannot answer until you provide documentation of the actual work they are doing, not what you think they did.
4)problem not related to altitude, meerely a coincidence. Check EGR valve.

Jason

[Green1]

1) you can't get your deli high enough for that to matter.

If you don't know what altitude it is, how do you know this? Your book saw fit to mention it, that certainly implies that it's an actual issue.

2) Idle emmisions

at idle this is rarely an issue, and the altitude compensator that I referred you to specifically adjusts things WITH the boost and is specifically for dealing with loss of power (something people don't seem to complain about when they're at idle!)

3) cannot answer until you provide documentation of the actual work they are doing, not what you think they did.

I told you what they did, you just didn't like the answer, I can't help you on that one

4)problem not related to altitude, meerely a coincidence. Check EGR valve.

funny coincidence that happens on many different vehicles when they do the same thing (Drive to altitude), especially considering the one that posted the question originally doesn't even have an EGR valve...

[FalcoColumbarius]

1) you can't get your deli high enough for that to matter.

Until you can tell me how high that is, how can I believe this?

Just a guess, but could it have something to do with the lines on the altimeter changing colour at a certain elevation?

Falco.

[Manitoba deli]

I'll have to check with my brothers on the specific altitude where compensation for lack of oxygen occurs. They are both pilots. I'm simply a ground mechanic (who provides proof not opinions)
Jason

[Green1]

1) you can't get your deli high enough for that to matter.

Until you can tell me how high that is, how can I believe this?

Just a guess, but could it have something to do with the lines on the altimeter changing colour at a certain elevation?

I somehow doubt that the vehicle is "fine" at one altitude, and suddenly "not fine" at a specific line.
The whole thing is gradual, starting at sea level, and working up from there, the higher you are, the further out of balance the vehicle, up until at some altitude (and unlike some others, I won't pretend to guess at what it is) the vehicle wouldn't be able to start or run at all.
At what point you have how much of an issue, hard to say for sure, but it is DEFINITELY noticeable at the altitude I live at, I've seen first hand the result of a failed altitude compensator on my old mercedes (jammed at sea level), and the difference on my L300, I've also seen the vast difference made by CVI's adjustment to Erebus' delica when they adjusted it for altitude (they had to guess the settings as they were doing it at sea level, however they gave Erebus instructions on how to fine tune it when he got home) And Mardy adjusted my L400 for altitude before I brought it home because he knew where I lived.

In all cases, the vehicle had excess smoke, and lower power until adjusted for the correct altitude, a turbo helps a lot, but it isn't magic, it can only do so much.

[Green1]

I'll have to check with my brothers on the specific altitude where compensation for lack of oxygen occurs

I can save you the hassle, there is no such magic line, on aircraft the turbos dump all the boost at sea level, and gradually close the wastegate to use increasingly more of the boost as they gain altitude, it all depends on the specific engine, and the size of the turbo, as to how high it can go before the turbo is no longer able to compensate adequately. (On aircraft the turbo wastegate operates in itself as a variable altitude compensator)
The same principle holds true on a delica, only on our engines we don't dump all our boost at sea level, we USE it, so at altitude when we loose pressure, there's no "extra" to pull from, as we climb the boost gets less and less, and the fuel mixture gets richer and richer, causing smoke and loss of power.

(who provides proof not opinions)

when you have proof that doesn't contradict you, let us know.

[Manitoba deli]

I apoligize for posting proof from a text book that taught the leading Diesel Mechanics of today. Let me know when the text book you wrote is in publish, and I'll use it.

Jason

[FalcoColumbarius]

Umm, just a minute. Are you talking about adjusting the boost or the IP?

As far as elevation coloured lines I would think that would work similar to the red lines on a tachometer. There is probably an "optimum" elevation, an "approaching dangerous" elevation and a "definitely not good" elevation, with a lot of greyness in between. So who has the exact numbers? I am reading a Mitsubishi Owners manual at the moment, perhaps it has something in there.

Falco.

[Green1]

I apoligize for posting proof from a text book that taught the leading Diesel Mechanics of today. Let me know when the text book you wrote is in publish, and I'll use it.

Where it came from is not in question, the fact that it contradicts you and states that there is a limit to the altitude compensation is the part you obviously aren't capable of reading...

[FalcoColumbarius]

Wow. Two more posts after this and we make three pages in three hours, not bad...

[Green1]

Umm, just a minute. Are you talking about adjusting the boost or the IP?

The problem with altitude is that there is less air, as a result, all other thing being equal, your fuel mixture will be too rich. To adjust for higher altitude you need one of 2 things, either more boost, or less fuel. Either one will solve the problem (more boost gives you more air, leaning out the mixture, or less fuel also leans out the mixture),
Manitoba Deli is arguing that the turbo magically makes more boost forever more no matter how high you go, and therefore no fuel adjustment is needed.
I'm stating that the turbo isn't magical, it can only give so much boost, and as such, at altitude you need to reduce the amount of fuel used.

(In aircraft they actually use the "increase boost" method, by having a turbo that isn't in use at sea level, and they use more and more of it as the plane gains altitude, but that is a far cry from an automotive system where people use all the boost at sea level and there's no "more" to use when you get higher up)

As far as elevation coloured lines I would think that would work similar to the red lines on a tachometer. There is probably an "optimum" elevation, an "approaching dangerous" elevation and a "definitely not good" elevation, with a lot of greyness in between. So who has the exact numbers? I am reading a Mitsubishi Owners manual at the moment, perhaps it has something in there

And here you are probably correct, but what they mean by "dangerous" is a completely different question. My owner's manual certainly didn't mention anything, but if you find something let us know. (I think the "redline" was at 2000m if I recall? (if 2000 is 'dangerous' then I would think 1000-1500 would be "not as optimal as sea level"))