What is the official spec for turbo boost on the 617? I have a FSM, but it is for non-turbo engines.

The car is currently at 9.5 psi, and I believe it should be around 10-12, but I do NOT want to take a wild guess.

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1976 BMW 2002- 100k
1995 BMW 325i 175k
1984 Mercedes Benz 300D Turbo Diesel- 270,000 mi

1981 Mercedes Benz 240D- Estimated 300,000+ mi Returned to the earth

0.7-0.9bar or 10.15-13.05psi. Most came from the factory with 7-9psi boost. Why? Reliability, economy, emissions, mistake? Nobody will know why unless we can get one of the builders/engineers to tell us.

.7-.9 bar is what MB has published?


It doesn't make sense for the manufacturer to have a spec of 10-13 psi, yet have the cars leave the factory at 7-9 psi. I'd say either MB didn't want owners destroying cars from high EGTs, or, emissions regulations demanded less fuel and therefore less boost. I would still go with the boost setting that MB designed the engine for.

__________________
1976 BMW 2002- 100k
1995 BMW 325i 175k
1984 Mercedes Benz 300D Turbo Diesel- 270,000 mi

1981 Mercedes Benz 240D- Estimated 300,000+ mi Returned to the earth

Dang it, now you made my break out my FSM.

It's .7-.8 bar. So I was 1.45psi over...

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I've got the SD set to 13.5 psi and, my guess is that it's too high.

Why, you say?

I don't think the ALDA has sufficient range to accept 13.5 psi of boost and the engine does not get anymore fuel above.......say.........11 psi or so.

I definitely see a temperature rise on the gauge........everytime I use maximum boost for more than 10 seconds or so. The 617 would never exhibit such behavior........more common to the fussy 603.

So, before I run the a/c for the summer, I'm thinking of dropping it back to 11 psi. I'll do another 0-60 time after I reset it.........it's currently at 12.7.......but........I'll bet that I don't lose any time.

However, the drop of 2.5 psi will definitely cause lower charge temperatures and lessen the rejected heat loading.

I don't know about that. I've got my ALDA at the max (No guts inside it) and at 14psi boost, I still get a bit of black haze at WOT. It may be just the turbo heating up the air but I'm not going to give it more boost to find out.

That's interesting. I can't get this 617 to smoke at anytime.......under any condition.

You might be right on the ALDA.........I'll have to reduce the boost and do another performance check. I don't think I can manage 13.5 psi during the summer with the a/c running and dealing with the CT hills.

Check out my smoke. Yes, it's coming out by the passenger door.

Right click and "save as" Needs WMP 10+ or VLC media player (Mac).

That's some decent smoke. Is that all created because the ALDA is eliminated?

Yes. What I did makes the IP think it's at full boost pressure all the time.

Is this the same car that is getting about 20 mpg?

Will it smoke at full boost pressure above 3K?

22.1mpg to be exact. It's been getting 22mpg long before I messed with the ALDA.

Yes, not a cloud like a full bombed-out Cummins but a slight black haze that can be seen in headlights. I'm going to try and setup another dyno session this weekend if I have the spare cash. I'll see exactly what's going on with HP #'s/smoke/water injection at that time.

A slight haze that can be seen in the headlights is perfectly normal. Just about every diesel will do that.......including this one.

The real test is black smoke in daylight under heavy accels.......that will tell you that you're overfueled. The black smoke at no, or low boost conditions confirms this. If you have no black smoke at full boost, then it's properly fueled at that operating point.

I converted the bar spec to PSI. .7-.8 bar = 10.1- 11.6 PSI. Thanks for taking the time to scan your FSM.

Earlier today, I turned up the boost to 12.25, and its definatly pulls harder when the turbo is producing full boost. I'm going to bring it back down to 11.5 PSI or so to be safe.

It appears to spool faster now, with the controller installed.

__________________
1976 BMW 2002- 100k
1995 BMW 325i 175k
1984 Mercedes Benz 300D Turbo Diesel- 270,000 mi

1981 Mercedes Benz 240D- Estimated 300,000+ mi Returned to the earth