If removing the ALDA is the solution, then something is wrong (at least on stock engines).
Removing the ALDA provides always max. potential of fueling. On full load the ALDA provides max. fuel (as if the ALDA is removed) saying that the IP is adjusted in that way. But this will cause smoke below full load. Or smoke is avoided but then not max. fuel is achieved under full load.

Maybe removing the ALDA works in combination with VTG where sufficient air is present more or less over the complete range of load.

After market turbo kits on non-ALDA IPs are all a compromise concerning smoke and performance.

Tom

Its only compromise from an emissions standpoint. It makes little difference to performance other than having a more linear feel (no rocket booster when the turbo lights).

If removing the ALDA is the solution, then something is wrong (at least on stock engines).
Removing the ALDA provides always max. potential of fueling. On full load the ALDA provides max. fuel (as if the ALDA is removed) saying that the IP is adjusted in that way. But this will cause smoke below full load. Or smoke is avoided but then not max. fuel is achieved under full load.

Maybe removing the ALDA works in combination with VTG where sufficient air is present more or less over the complete range of load.

After market turbo kits on non-ALDA IPs are all a compromise concerning smoke and performance.

Tom

You did a double post.

Sorry for that, there was some error message..

You are right. But emission here in Germany (in all Europe) is a serious matter.
All I wrote in the "lever thread" is just the original engineering behind the ALDA and that can be modified.
My intention is to adapt the given (and needed) parts to the modified set up.

Tom

I agree with Forced's idea of removing the ADA on NA engines. I have my 616 IP adjusted up and replaced the ADA with a set screw. I am using it to fine tune the fuel. IMO this works because a NA engine dose not have an increase in VE during acceleration or turbo lag to get past. If I tug mine off the line or floor it, I will get some smoke but not during normal driving.

For Turbo engines the use of a fuel control would keep the amount of smoke to a min and provide max fuel only when the boost is there, regardless of foot position.

I have sketched up a custom ALDA that allows you to adjust the PSI that the ALDA starts to move, the total travel ( allows the entire pin travel to be used), and the non boost (low power, idle) start height.

You would adjust the low power height for pre boost operation with out smoke, then you can adjust the max fuel height, ( full boost, power) for minimal smoke or none at all. The last adjustment is when it starts adding fuel, (what boost pressure it comes in) this will allow you to trim the fuel curve. You even could use two springs and have a progressive trim rate for heavily modified engines.

It is on my list of things to do to my recently acquired
300D with a 300SD engine, and it is a long list. If any one is interested I will make a better CAD drawing. the only part that I have not verified is the bellows. I was thinking of using a Harley Davidson Evo carb bellows.

I'm a bit late on getting to this thread, but, some fundamental understanding of the ALDA is necessary.

The engine is supplied with a given anount of air which is basically the cylinder volume at rpm's below boost. If the IP is calibrated properly, it will provide just enough fuel to use all the available air in the cylinder when you mash your right foot. There is no smoke and the power available is the maximum possible. Naturally, M/B would err on the side of too much air due to the desirability of no smoke. To ensure maximum power, a slight bit of smoke is desirable.

Now, when the engine is turbocharged, the cylinders are supplied with additional air because it's pressurized beyond atmospheric pressure. The cylinders might have 27 psi with full boost as compared to 15 psi n/a. This requires more fuel.

So, either we provide too much fuel when below boost..........or we don't provide enough fuel when on boost. A conundrum.

But, M/B designed the IP with a device called the ALDA..........which will restrict full fuel when the engine is below boost levels. The IP can then be calibrated for proper fuel at 27 psi and the ALDA can restrict fuel throughout the range from 15 psi to 27 psi.

Therefore, the first question is whether the IP is properly calibrated for maximum fuel? Using the full load screw, it's possible to turn up the fuel to the point of smoke under maximum power. This is the best you can get with the available air.

Once this has been accomplished, the ALDA can be utilized to restrict fuel below maximum manifold pressure (27 psi). Or, you can simply restrict fuel with your right foot.........your choice. Both do exactly the same thing. The engine cannot use maximum fuel unless it's under full boost conditions.

There is no benefit to attaching any type of cable to the ALDA for an adjustment while driving. Either you utilize the ALDA to restrict fuel (and the subsequent smoke) at lower rpm's without full boost.........or you use your right foot to accomplish the same thing.

Let ask- why at say a tractor pull do they bellow black smoke all the time? If max power occurs when smoke comes out, would they not just adjust so that a bit of smoke comes out?

I'm either missing something you others are. The alda is a fuel adjustment of the IP based on boost. The IP will deliver fuel from say 1 to 5, if you adjust it the full load (FL) and TC it may then give you fuel from 2-6 or 3-7, or even 4-8 (hypothetical ranges to illustrate the idea). At full boost a IP delivering fuel at the level 8 you may get some smoke, but a lots of smoke at idle and run away idle. You cannot have this, so you must change the FL, TC and alda- you have to move the sliding scale back to 3-7 or 2-6. By remote alda changes you may be able to expand the range to 1-8.

If the engine doesn't get enough air to burn all the available fuel.........how can adding more fuel give any additional horsepower?

The ALDA is simply a limiting device. It does not have any capability of adjusting the maximum fuel.

I don't see how it's possible to get any smoke at idle due to too much fuel. The engine would simply run away.

You can get excessive smoke underway if you mash the pedal and are below boost conditions. This is the purvey of the ALDA.........it prevents the driver from dumping too much fuel when there is insufficient air.

That's the theory, but then no one would ever need to adjust the FL or TC because you can get some smoke on nearly all 617's by adjusting the alda alone. But we know this to not be true- you can get more power with the FL and TC adjustments. This is why nearly all diesel tuners (when they run on the track) are "burning coal" ie pouring out smoke. The first hint of smoke does not seem to be the hard fast shut off of the capacity to make more power with more fuel. At 12-17 psi on my car I get very little smoke- but I do at lower rpm, and I think I could add more fuel- but the engine will run away at lower rpm's with more TC and FL adjustments, OR more alda adjustment. I'm searching for a way to add more fuel in the higher rpm/higher boost area without adding it in the lower boost/rpm range.

I'm a bit out of my league with IP adjustments, but, it does sound like you need to make two different adjustments to the IP. When you adjust full load, the idle adjustment must also be reduced?

There is a limit to the adjustability.............at a certain point, you can't get it to idle.............but, I've not attempted it. The folks across the street have done extensive work on these adjustments and they are critical to avoid the type of problem you are experiencing.

I do believe that the adjustment is in the IP itself...........remotely attempting to adjust the ALDA is a bandaid to the real issue.

post #14
or increasing the ALDA travel by reducing the diameter of the guide pin.
This is the screw behind the linkage lever. Gives only a little more but easily possible.

Tom

Well, you found it! Leave the ALDA on (for low boost limiting) and, tweak the max fueling settings in the pump (TC, rack limiter), injectors, and DVs... Or do all of the above, except take the ALDA off and limit with your foot.

I have not taken my ALDA off, but it sounds like the main point is that the ALDA has an effective range of boost, and outside that range it does not work as expected. Hence the modification proposed by Tomnik

You've missed the whole boat I think- by adjusting the FL and TC I am adding more fuel, and at higher boost/rpm I'm still lacking fuel to burn.
I could add more fuel, by adjusting the TC and FL more- but an unintended consequence is that the engine does not return to idle. What I'm saying is that I'm at that limit right now- and by changing the alda setting I also can add more fuel which at low rpm causes runaway. So if I could adjust on the fly- ie only when accelerating at higher boost/rpm conditions I would get the more fuel wanted, and then back off the alda when decellerating or at idle and the engine would not run away. Neither the right foot or removing the alda would do anything to solve this issue.