Turbo and A.L.D.A. Service - Page 2 - PeachParts Mercedes-Benz Forum

Silber Adler · #16 01-21-2013, 10:19 PM

My 85 will cruise at 60 mph at 4-5psi. ARV blocked and EGR blocked Taking off the ALDA didn't change the boost at that speed. It does come up a bit faster below that though.

Adriel · #17 01-21-2013, 10:25 PM

Quote:

Originally Posted by Silber Adler

My 85 will cruise at 60 mph at 4-5psi. ARV blocked and EGR blocked Taking off the ALDA didn't change the boost at that speed. It does come up a bit faster below that though.

Thank you, good to know!

When the Volvo is done I might take the chance and remove the E.G.R. flap for diagnostic purposes

and turn the turbo boost up 0,2 bar so that I am doing about the same.

I have totally eliminated the vacuum lines and the devices on the fender just for diagnostics.

Silber Adler · #18 01-21-2013, 10:40 PM

I made a manual boost controller, stuck it in the waste gate pressure line. It will now go up to 13.5-14 psi. It doesn't boost it more cruising.

When on the go pedal it doesn't limit at 9 psi but can keep going up to 14.

Adriel · #19 01-22-2013, 09:48 AM

Quote:

Originally Posted by Silber Adler

I made a manual boost controller, stuck it in the waste gate pressure line. It will now go up to 13.5-14 psi. It doesn't boost it more cruising.

When on the go pedal it doesn't limit at 9 psi but can keep going up to 14.

Thank you so much for the reply!

Why do you want to control it, especially if it doesn't boost the cruising boost pressure?

My reason is the manual specifies 0,8 bar and like to be there or a tad past for best fuel economy. I was challenged I couldn't get over 25M.P.G. and a couple tankfuls I have done it. If I could get 27 I be elated. It is a 3.300 pound tank with not the best aerodynamics, so I know it has limits. So does the Volvo which only a handful have been able to break the 21M.P.G. mark and was regularly doing 24 to 25M.P.G.. The turbo leans out the mixture so believe the folks that it will help economy. But, I am not about to spend wads doing it.

Silber Adler · #20 01-22-2013, 10:09 AM

The way I understand it, .8 bar is the max rather than the cruising boost. I did what I did to raise the max because it was only boosting to 9 before limiting. I wanted it higher just in case I needed more max.

My mileage is similar to yours. I have had 5 or 6 fills, the best was 32 and the worst at 24 (including a lot of below freezing weather).

Adriel · #21 01-22-2013, 03:46 PM

Quote:

Originally Posted by Silber Adler

The way I understand it, .8 bar is the max rather than the cruising boost. I did what I did to raise the max because it was only boosting to 9 before limiting. I wanted it higher just in case I needed more max.

My mileage is similar to yours. I have had 5 or 6 fills, the best was 32 and the worst at 24 (including a lot of below freezing weather).

That was the way I understood it too! So, thank you for confirming!

So if your cruise is 0,4 bar and you increase the pressure by 0,2 bar, cruising then should be 0,6, and if you romp it to 4.000R.P.M. it should then be 0,8 bar.

I thought wagens were less efficient than the sedans? My worst was 21M.P.G. (fill up by P.O.) to a couple 26M.P.G. because of being on the highway. Think this tank is going to be decent as 110 miles on a quarter tank.

With the A.L.D.A. removed there is LOADS of power and scared myself when I first pulled out of the drive!

Feels so much more confident, like I can get out of the way. If economy stays the same or improves, I just might be tempted to run without. Make the system simpler.

I hardly ever romp so doubt I have an issue of over boosting.

Silber Adler · #22 01-22-2013, 04:16 PM

Hi again
Just looking at my log the best was 32.7 worst 24.7 avg is 27.5 for 6 fills. Now that winter is upon us I am running snow tires. The wear of the engines and drive trains and wheel alignment might more difference than the body style.

I don't think that these chassis' are too aero efficient. The square back might be as good as the trunk version. The trunk is too low to help that much. The front half is pretty much identical. Of course if the is a difference in weight, that can make a bit of difference in low speed stop and go type of driving.

Adriel · #23 01-22-2013, 07:47 PM

Quote:

Originally Posted by Silber Adler

Hi again
Just looking at my log the best was 32.7 worst 24.7 avg is 27.5 for 6 fills. Now that winter is upon us I am running snow tires. The wear of the engines and drive trains and wheel alignment might more difference than the body style.

I don't think that these chassis' are too aero efficient. The square back might be as good as the trunk version. The trunk is too low to help that much. The front half is pretty much identical. Of course if the is a difference in weight, that can make a bit of difference in low speed stop and go type of driving.

Thank you for the information!

So 27 should be obtainable, which is good news. Though do have about 80.000 more miles.

I know they are not efficient as just look at the gap between the grill and the headlights! I just bet you there is turbulence behind the grill. Plus the front is flat with an almost flat windshield. Then there is the underside. In the Volvo community they actually mount belly pans to smooth things out especially the rear bumper, which don't think is quite as much as an issue. Been tempted with all the cardboard I have around here to fab something and see for fun what the result is. But alas, too many other things to do.

Phil · #24 01-22-2013, 09:47 PM

Did you adjust the waste gate?

Silber Adler · #25 01-22-2013, 11:13 PM

I made a manual boost controller. They are real simple. There are a number of commercially made ones. They are basically a brass T fitting with a check valve in it that reduces the output pressure of the boost line by a few pounds. Of course you can dig into the waste gate but with my luck I would tear the diaphragm.
A Boost Controller Thread

Brian Carlton · #26 01-24-2013, 12:29 AM

Quote:

Originally Posted by Silber Adler

I made a manual boost controller, stuck it in the waste gate pressure line. It will now go up to 13.5-14 psi. It doesn't boost it more cruising.

Setting the boost at 13.5-14 psi shows that you do not understand the purpose or the intent of additional air forced into the combustion chambers. All you have accomplished is to increase the temperature of the charge air with absolutely no benefit to performance or fuel economy.

In fact, the general consensus is that the lower boost numbers produce the best fuel economy.

Any boost levels above 12 psi are counter-productive and should be avoided, unless the IP has been modified for additional fuel.

tram · #27 01-24-2013, 04:43 PM

Quote:

Originally Posted by Brian Carlton

Setting the boost at 13.5-14 psi shows that you do not understand the purpose or the intent of additional air forced into the combustion chambers. All you have accomplished is to increase the temperature of the charge air with absolutely no benefit to performance or fuel economy.

In fact, the general consensus is that the lower boost numbers produce the best fuel economy.

Any boost levels above 12 psi are counter-productive and should be avoided, unless the IP has been modified for additional fuel.

You are correct- he doesn't understand it now, but I know Adriel and he will figure it out.

But yes, Adriel... that boost is really just too high. Boost on a Diesel is sort of like ignition timing on a VW- you bump it a little forward and the car runs like a racecar, but there can be a high price to pay down the road. As Brian said, the problem is that your injected fuel amount is mechanically limited by the design of the IP and injectors... not to mention the overall tolerances and LIMITS of the engine design.

What a lot of people don't realize about automotive engineering and why things are the way they are is that engineering and setting specs is almost always a "best compromise" between two or more opposing factors... let's say acceleration speed and longevity, for sake of argument. The engineer's job is to find the best compromise between the two. Once that parameter is established, a dilettante like you or I trying to improve one factor can only do so to the detriment of the other- and that's probably the biggest thing non- engineers don't understand. The second biggest thing they don't understand is the hidden pitfalls and costs of getting fixated on ONE performance factor while completely ignoring the big picture.

It's easy to get fixated on the "I'm getting 100 MPG!!!" or "My 300D goes 0-60 in seven seconds!" type posts. Either those people are completely full of balogna, or they're going to be the proud owner of a hunk of melted metal very soon.

Brian Carlton · #28 01-24-2013, 05:43 PM

Quote:

Originally Posted by tram

Either those people are completely full of balogna, or they're going to be the proud owner of a hunk of melted metal very soon.

absolutely correct.

Adriel · #29 01-24-2013, 09:35 PM

Quote:

Originally Posted by Brian Carlton

Setting the boost at 13.5-14 psi shows that you do not understand the purpose or the intent of additional air forced into the combustion chambers. All you have accomplished is to increase the temperature of the charge air with absolutely no benefit to performance or fuel economy.

In fact, the general consensus is that the lower boost numbers produce the best fuel economy.

Any boost levels above 12 psi are counter-productive and should be avoided, unless the IP has been modified for additional fuel.

Where the heck did I say 14P.S.I.?! I would NEVER go that high! I am not going to mount gauges as like the design the way it is. That then limits me to STOCK, which is 12P.S.I..

The turbo charger is to increase the intake air above atmospheric pressure. Pressurization causes heat, so after a point, an intercooler to cool the intake air. There is also heat due to the exhaust which affects the turbo.

Please show me the data. I am about facts, not bias. Got a graph, so a value can be used?

Additional fuel can mean decreased economy. I don't want to mess with the injection pump as don't have a pyrometer. I know the limits and will respect them!

Quote:

Originally Posted by tram

You are correct- he doesn't understand it now, but I know Adriel and he will figure it out.

But yes, Adriel... that boost is really just too high. Boost on a Diesel is sort of like ignition timing on a VW- you bump it a little forward and the car runs like a racecar, but there can be a high price to pay down the road. As Brian said, the problem is that your injected fuel amount is mechanically limited by the design of the IP and injectors... not to mention the overall tolerances and LIMITS of the engine design.

What a lot of people don't realize about automotive engineering and why things are the way they are is that engineering and setting specs is almost always a "best compromise" between two or more opposing factors... let's say acceleration speed and longevity, for sake of argument. The engineer's job is to find the best compromise between the two. Once that parameter is established, a dilettante like you or I trying to improve one factor can only do so to the detriment of the other- and that's probably the biggest thing non- engineers don't understand. The second biggest thing they don't understand is the hidden pitfalls and costs of getting fixated on ONE performance factor while completely ignoring the big picture.

It's easy to get fixated on the "I'm getting 100 MPG!!!" or "My 300D goes 0-60 in seven seconds!" type posts. Either those people are completely full of balogna, or they're going to be the proud owner of a hunk of melted metal very soon.

Tram, thank you for the help!

I understand more than you all will give me credit for! But, understand as most folks think I am retarded and give me credit for anything, not even when it is obvious, like some of my art.

Fine, I was wrong about 12P.S.I. being the specification: it is actually 11.603019P.S.I.. Now I HIGHLY doubt the gauge could be that accurate especially with tolerances. But, 11.603019P.S.I. isn't 9P.S.I. which I am at now. The whole bloody point of all this was to get to the proper specifications. If I never had checked this, I would not have found the faulty A.L.D.A. and my transmission still be shifting hard. I asked for your help but you didn't know what to do. Having dealt with vacuum issues on the Squareback I eliminated the unnecessary so less to go wrong and then observed the results. For some reason, according to some, it helped. I do love stock, but sometimes one has to look at the intent. When the OM617a in the W123 was introduced there was no A.R.V. or E.G.R.. It was forced on Mercedes, so why keep them? The oxidixer does less harm than good, if any harm, so have no problem with it, if anything glad to have it. I believe that is why I get only a light hazing if I bury the pedal, which I only did once today to get the next green light to get onto the freeway. Did have the advantage of the folks behind waiting a long while before moving!

A little goes a long ways!

I timed the Squareback to 10 degrees per Russ saying 15. I wanted to be safe and didn't have the money to tell what the full advance was. The reason Volkswagen specified the timing they did was for emissions. Same for the Mercedes, a little goes a long ways. However, the turbo specifications is that is where it operates the most efficient. Folks regularly run 15P.S.I. or more, but they have equipment to tell them when there is an issue. Some even upgrade the turbo and run in the 20's. I have no desire to go above stock. I even lost the desire to upgrade the exhaust and/or intake as apparently the E.G.R. flap can be removed for testing.

I understand about changing one thing is the detriment of another. Take for instance all these folks throwing out the A.L.D.A.s. I think what a waste, can I have it? The A.L.D.A. is to decrease the fuel until the turbo gets going, preventing high exhaust temperatures. Yes, one does get A LOT more pep, but at what cost? It be better to adjust the torque control, idle, and rack, and get the fuel via tuning.

F.Y.I., Vater read all the encyclopedia articles when he was eight years old, has been an engineer for at least forty plus years with part of his duties being destructive testing.

Plus, he has a Master's in Physics and a member of Sigma Pi Sigma. Basicly, if I have a question, he can answer it or help me at least sort it. That is something I love about him, when he has the time: can help or fix about anything. Bet he could give me the run down on turbos. He already explained several times why I shouldn't own a diesel...

All I want from my lovely Mercedes is the best.

If she is supposed to take 14 seconds to get to 60M.P.H. and only doing 14.5 seconds, then I am going to ask her why. Most likely she will say I am tired and I need an adjustment.

I trust what you did, but I have gone from a hard hitting slow Mercedes to a mild hitting, comfortable, almost rocket that is regularly getting better economy!

We have our differences and that is what makes the friendship enjoyable!

All you have to do is convince me I am wrong and I will make corrections!

tram · #30 01-24-2013, 10:17 PM

Of course, Adriel, all that is understood.

Keep in mind that detailed and even elementary explanations of things are never given due to posters thinking one is "retarded"; rather, it's that none of us one here really has any ideas what another poster's experience level or skill set really is.

AND, what's more- even if the skill set is great and the level of experience is very high, it's always good to review the basics. I've been in the German car game off and on since 1975, and you know what the first tool is that I grab, even if I've done a repair hundreds of times?

The repair manual.

Even the most experienced among us are never immune to brain farts or disorientation. The day we think we are- is the day we're going to mess something up big time.