A few things conspire against these cars:

It has been said of the Germans and how they expect cars to perform, that first gear is just to get you going, all of the fun starts above that.

The gearing in most of these turbodiesels is designed to give good cruising speed, efficiency, and noise level, not fast launches. Mercedes typically was the luxury end in Germany in the latter half of the century, left the noisy race-car type stuff to BMW et al. Tuners such as AMG (a separate company at that time) would make hotrods out of them.

To this end, the torque converters are also lower stall than what you would want for fast launches, smooth not fast.

If you know someone in the transmission business, changing to a higher stall torque converter could put your launch RPMs solidly into the meat of the power curve, I.E. above where boost gets strong. Lowering the final-drive to a higher ratio would also get you off the line, but that will cost you in the top end with more noise and fuel use.

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Gone to the dark side

- Jeff

I can get 10 psi revving at idle with my VGT: http://www.youtube.com/watch?v=hyTxOwbhwqs

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

The "slow off the line" feel is directly related to the lack of horsepower. Most other vehicles have 175hp as a bare minimum with a first gear that might be pushing 4:1. The combination results in a launch by a Hyundai that will easily blow off an SDL.

Sure, they can run............until they run out of horsepower...........which will occur around 100 mph when one only has 125 hp. The SDL is a bit higher, maybe 115 mph, but with 150 hp, it's also limited.

Yep this makes sense. The job of the turbo is to cram as much air into the cylinder as possible. I think the 6.2 is the same HP rating as the 3.0L 603Turbo MB engine. So I guess the turbo is craming as much air into the cylinder as the NA 6.2 gets with twice as much cylinder capacity.
So you're right at the starting line the NA 6.2 diesel has as much air coming in as the engine will get at full boost (since it has no full boost!). I do notice some nice extra power with the 6.2 at around 75MPH. Probably due to ram air or the engine being at a higher RPM (less bogged down).

But I guess if we want faster take offs a variable turbo as you said is probably the answer.

I've never driven a VW TDI but it seems like they have a pretty quick 0-20MPH... is it variable turbo powering that?

__________________
-E300d '99 350k
-Suburban '93 220k
-TDI Jetta '03 350k
Sold
-F250 '96 7.3
-Dodge Ram 12V
-E320 '95 200k
-E320 Wagon 1994 155k
-300d Turbo '87 187k miles
-E320 1994 200k
-300d Turbo '84 245k (sold to Dan62)
-300d Turbo '84 180k
-300sd '80 300k
-7.3 Powerstroke Diesel 15P Van 500k+ miles
-190d '89 Non Turbo 2.5 5cyl 240k (my first MB)
Tom's Imports of Columbia MO Ruined the IP in changing leaky delivery valve O-Rings - Refused to stand behind his work. Mid-MO MB drivers-AVOID Tom's.

Most of the Japanese vehicles give an excellent 0-20 feel by using a low first gear and a variable fast throttle geometry. You press lightly on the pedal..........but you get 30% of the available travel...........very crafty, those Japanese

Ha ha, kind of deceiving actually especially the pedal travel part.

Did you say Japanese? VW TDI?

I don't care much about what VW does since I think MB's old stuff is way better in build quality but are the VW engines Japanese? I always thought it was Porsche, Saab, VW out of Germany.

__________________
-E300d '99 350k
-Suburban '93 220k
-TDI Jetta '03 350k
Sold
-F250 '96 7.3
-Dodge Ram 12V
-E320 '95 200k
-E320 Wagon 1994 155k
-300d Turbo '87 187k miles
-E320 1994 200k
-300d Turbo '84 245k (sold to Dan62)
-300d Turbo '84 180k
-300sd '80 300k
-7.3 Powerstroke Diesel 15P Van 500k+ miles
-190d '89 Non Turbo 2.5 5cyl 240k (my first MB)
Tom's Imports of Columbia MO Ruined the IP in changing leaky delivery valve O-Rings - Refused to stand behind his work. Mid-MO MB drivers-AVOID Tom's.

Never drove a TDI.........but, the technology is fairly universal. Convince the driver that the vehicle has quite a bit more power than it actually does..........the launch is key to this feeling............ultimate acceleration time is of less importance............during a test drive.

I drove a new Jetta (not diesel) about a year ago, and I simply HATED the 6 gear automatic. I couldn't step on the pedal without it shifting at least once. I don't think I could ever get used to that.

Yes you're right about it being universal. Even Ford and GM's newer vehicles are like this. Personally I don't like it. It's like a cheap chinese pot with a bad taper. I build tube amps and usually use good pots. But the mark of a cheapo pot is you get 90% of the volume in the first 10% of the wipers travel.

There is a much nicer taper, I think, in the MB's pedal travel. Want to ease out? no problem, want the turbo to kick in very quickly? Floor it.

I think this is nice! I wouldn't complain one bit about it. It sounds like I am by my original title to the thread and I think I have had my original question answered. Just something I've always wondered since driving MB diesels the last 3-4 years. Now I understand. It seems like somewhat of a dead first second to second and a half but once the air flow happens it's like a roller coasters first drop! Very nice feeling. I haven't noticed it with many other diesels. And I have to say the 603 has one of the best sounding diesel engines I've heard. Really has a nice hum to it at 60MPH, it sounds like quality in motion!

__________________
-E300d '99 350k
-Suburban '93 220k
-TDI Jetta '03 350k
Sold
-F250 '96 7.3
-Dodge Ram 12V
-E320 '95 200k
-E320 Wagon 1994 155k
-300d Turbo '87 187k miles
-E320 1994 200k
-300d Turbo '84 245k (sold to Dan62)
-300d Turbo '84 180k
-300sd '80 300k
-7.3 Powerstroke Diesel 15P Van 500k+ miles
-190d '89 Non Turbo 2.5 5cyl 240k (my first MB)
Tom's Imports of Columbia MO Ruined the IP in changing leaky delivery valve O-Rings - Refused to stand behind his work. Mid-MO MB drivers-AVOID Tom's.