85 turbo still 0-60 18 seconds at best... - Page 2 - PeachParts Mercedes-Benz Forum

ichbineinekrous · #16 08-08-2007, 10:47 AM

egr is disabled, ARV not. Can I just remove the line and cap both ends? Checked the shift points last night.
2nd- 23 mph
3rd- 45 mph
4th- 63 mph

This is pedal to the floor. Also in response to forced induction, yes the linkage was adjusted exactly in the manner you describe, with a brick, ip arm at full travel. The rubber bushing on the firewall, that translates up/down pedal motion is in pretty good shape. I have no prob tweaking the ALDA, but as it was just completely removed, thus removing all restriction to the ip fuel metering and the car still wouldn't break the 18 sec. barrier, I don't think that's my problem. Of course, I'm wrong all the time, I have an ex-wife and a girlfriend.

Zoonhollis · #17 08-08-2007, 11:28 AM

Quote:

Originally Posted by TheDon

just letting you know.. Lance(FI).. knows his stuff

You could remove the ALDA and see how that works for you

That's nice. However, I know my stuff too. How do I know? Because I have done this procedure several times, and if you think you can get any more than a modest gain by adjusting boost alone, you're living in fantasyland where everything's made of chocolate and the laws of thermodynamics are mere myth. Like I said above, use the search tool. You'll see that I'm right.

winmutt · #18 08-08-2007, 12:02 PM

Quote:

Originally Posted by Zoonhollis

That's nice. However, I know my stuff too. How do I know? Because I have done this procedure several times, and if you think you can get any more than a modest gain by adjusting boost alone, you're living in fantasyland where everything's made of chocolate and the laws of thermodynamics are mere myth. Like I said above, use the search tool. You'll see that I'm right.

You clearly have no clue how the ALDA work. It is a fuel cut off device. All you are adjusting is the start point cut off not how much fuel is moved at max boost. At max boost ALDA is no longer affecting the fuel. Adjusting an ALDA should only be done in the case where the internal springs and diaphragm are no longer at their original strength.

Zoonhollis · #19 08-08-2007, 12:05 PM

Fuel delivery can be enriched via the ALDA. Any idiot knows that (except one)

This must take place before performance gains will be realized. I feel like a broken record here...

Listen, I went through all of this with my '84 300D a few years ago. Removing the spring from the wastegate cover was an ordeal in itself (not to mention putting it back on). After a few adjustments to the wastegate, I was seeing 13.5 psi in boost. Great, I thought, now my car will fly. It did nothing. In my puzzlement, I came back to the forum here and explained what I had done. Many of the experts (including the Dieseling Doktor, one of the foremost authorities on the matter) suggested the additional ALDA tweak. I then backed it out (enriched) in small increments until a difference was noticed. I adjusted once more and I had a veritable rocket sled for a car. Now, tell me again why I don't need to adjust the ALDA...

ConnClark · #20 08-08-2007, 12:25 PM

To disable the ARV on the turbo just stuff a couple of BBs in the vacuum line. Since you have disabled the EGR the ARV just robs you of power and makes your emissions worse.

I found when my ARV quit

working my car gained a lot of low end. The ARV bleeds off boost below 2500 rpm. When it closes you can see your boost gauge jump. By playing around the rpm where it opens and closes you can feel the difference in power.

According to the Fins the stock turbo on these cars is not efficient above 14.5 psi.

ConnClark · #21 08-08-2007, 12:59 PM

Quote:

Originally Posted by Zoonhollis

Fuel delivery can be enriched via the ALDA. Any idiot knows that (except one)

This must take place before performance gains will be realized. I feel like a broken record here...

Listen, I went through all of this with my '84 300D a few years ago. Removing the spring from the wastegate cover was an ordeal in itself (not to mention putting it back on). After a few adjustments to the wastegate, I was seeing 13.5 psi in boost. Great, I thought, now my car will fly. It did nothing. In my puzzlement, I came back to the forum here and explained what I had done. Many of the experts (including the Dieseling Doktor, one of the foremost authorities on the matter) suggested the additional ALDA tweak. I then backed it out (enriched) in small increments until a difference was noticed. I adjusted once more and I had a veritable rocket sled for a car. Now, tell me again why I don't need to adjust the ALDA...

The ALDA doesn't adjust maximum fuel delivery. It does adjust when you are able to get it however.

As far as increasing boost goes with out a fuel increase, you will see some minor gains. The NACA did several experiments with diesel engines and boost. The picture attached is a picture of the results of a test using a DePalma Supercharger to generate the boost on a prechamber engine from NACA-report-577. In each case the power to drive the blower was subtracted from the output of the boosted test.

In all cases at all fuel levels except for the lowest level of boost, the MEP is higher than it was for no boost . Also in all cases except for the lowest level of boost, the BSFC was lower than with no boost meaning efficiency went up. In the range of fueling where the NA configuration exceeds performance of the lowest boost level it is probably due to frictional losses to drive the supercharger and not the trade off of power gained from boost vs work to compress the air.

Boost does several things to increase efficiency. It reduces ignition lag, It increases the percentage of fuel burned, It reduces heat lost to the piston and cylinder walls, it increases the specific heat ratio of the power stroke charge, and it also reduces the relative peak pressure to better approximate the ideal diesel cycle to name a few. In short boost will get you more power at the wheels as long as the power to create it doesn't exceed the additional power reaped from the increase in efficiency.

Now you can add more energy to the equation by adding more fuel and get even more power out but it is not required to get a modest gain.

Zoonhollis · #22 08-08-2007, 01:13 PM

Exactly, but this guy wants to go from 18 seconds 0 - 60 to 13 seconds. A "modest" gain might net him another half second...better bust the cap off that ALDA.

winmutt · #23 08-08-2007, 01:37 PM

Quote:

Originally Posted by Zoonhollis

Exactly, but this guy wants to go from 18 seconds 0 - 60 to 13 seconds. A "modest" gain might net him another half second...better bust the cap off that ALDA.

You stated that it had to be adjusted because of the change in the turbo, I was simply arguing this is not the case. And yes, the further you back it out the sooner you will get max fuel. But as I stated this adjustment is only needed due to weak internals, not because you changed the turbo. Had you adjusted it prior to the turbo you would have seen a similar result. Had you bothered to adjust the linkage?

Zoonhollis · #24 08-08-2007, 01:49 PM

The turbo and ALDA adjustment was the last thing done in a long list of to-do's. I heeded the advice of the veterans on this forum and it paid huge dividends. I'd suggest the same for this guy...

I also consulted the Diesel Doktor and the Easley/Ritter site. They concurred that the ALDA tweak was an essential step in gaining APPRECIABLE performance. 'Nuff said.

ConnClark · #25 08-08-2007, 02:12 PM

killing the ARV should be the first step. Reduced boost off the line also reduces fuel provided by the ALDA.

ichbineinekrous · #26 08-20-2007, 05:09 PM

ARV is plugged. Boost controller installed, no change. Still averaging 19.5 seconds. I should say before anyone else has the idea that my speedo is pretty accurate, checked with GPS.

Sound like I need to get the injection timing checked. It sounds like with RIV lights it should be a <30 min. job. I.E. something that a shop could do for me for not much money. And then possibly having the injectors tested and/or replaced? On a side note, my timing chain stretch is about 3 degrees, within spec. to my knowledge. The latest 0-60 runs were done immediately after replacing both engine compartment fuel filters, wanted to negate that variable due to the fact I've had some black crud in the tank issues.

Brian Carlton · #27 08-20-2007, 05:34 PM

Quote:

Originally Posted by Zoonhollis

The turbo and ALDA adjustment was the last thing done in a long list of to-do's. I heeded the advice of the veterans on this forum and it paid huge dividends. I'd suggest the same for this guy...

I also consulted the Diesel Doktor and the Easley/Ritter site. They concurred that the ALDA tweak was an essential step in gaining APPRECIABLE performance. 'Nuff said.

You've got yourself confused with the combination of two different adjustments.

Adding more boost........up to the maximum of approx. 13".........will provide the engine with more fuel via the ALDA. No adjustment is required of the ALDA to get this fuel.

However, and completely separate from the above paragraph, adjusting the ALDA will shift the fuel curve and provide more fuel to the engine for a given level of boost. This has the effect of providing slightly increased "feel" of performance for the driver. However, it does not affect maximum fuel and the 0-60 times will be unaffected.

FWIW, the "Diesel Doktor" is also confused as to the function and performance of the ALDA.

Brian Carlton · #28 08-20-2007, 05:37 PM

Quote:

Originally Posted by ichbineinekrous

ARV is plugged. Boost controller installed, no change. Still averaging 19.5 seconds. I should say before anyone else has the idea that my speedo is pretty accurate, checked with GPS.

Sound like I need to get the injection timing checked. It sounds like with RIV lights it should be a <30 min. job. I.E. something that a shop could do for me for not much money. And then possibly having the injectors tested and/or replaced? On a side note, my timing chain stretch is about 3 degrees, within spec. to my knowledge. The latest 0-60 runs were done immediately after replacing both engine compartment fuel filters, wanted to negate that variable due to the fact I've had some black crud in the tank issues.

The IP timing is not the major issue. Even if it's late by six degrees, you won't pickup five seconds with the adjustment. It's worth checking, but, the chances of it solving the issue are negligible, IMHO.

It's slowly closing in on the fact that the engine doesn't get the additional fuel that the ALDA would normally provide. With the ALDA removed, you should see some serious black smoke when you mash the pedal. I'm concluding that this did not occur...........correct? If so, then the IP is not performing properly and it's got to be recalibrated/replaced.

ichbineinekrous · #29 08-21-2007, 07:19 AM

ok. thanks Brian. Sounds like I've reached the end of what I can do myself. And I'm assuming I don't want to take this injection pump to just anybody. I read the procedure for adjusting the full load screw inside the ip, is this something I can do without fear of damaging the pump? If not, can anyone suggest a good diesel injection specialist in or around central NC? Many thanks.

winmutt · #30 08-21-2007, 07:43 AM

Quote:

Originally Posted by ichbineinekrous

ok. thanks Brian. Sounds like I've reached the end of what I can do myself. And I'm assuming I don't want to take this injection pump to just anybody. I read the procedure for adjusting the full load screw inside the ip, is this something I can do without fear of damaging the pump? If not, can anyone suggest a good diesel injection specialist in or around central NC? Many thanks.

You can't damage the pump (with minute changes) however you can certainly blow the engine. Have you adjsted your linkage? Pop tested your injectors?