OM603 semi-super pump testing, fitted with Bosch 6.0mm elements - Page 7 - PeachParts Mercedes-Benz Forum

winmutt · #91 03-07-2011, 04:46 PM

Quote:

Originally Posted by Kurt Smith

No both my stock 300SDL's have Garrets but not the same A/R as the 350 Garret right?

I meant the pump.

Kurt Smith · #92 03-07-2011, 05:01 PM

Rolf,

Sorry, no the stock 300 SDL pumps are going to be upped to 6mm and benched. Don't have the Bosch numbers handy but I can post tonight.

M G,

I might be able to help you get you 603 pump rebuilt with 6mm but it would have to be cool with the moderators here first and shipping to Canada could be a problem. I have no idea about customs. We are just learning (slowly

) what works for now, but it looks very promising.

M_G · #93 03-07-2011, 07:22 PM

Kurt, thanks for your kind offer.
Lets hope it will be cool with the moderators here.
I will take care for the shipping and customs.
Any ideas what is the turnaround time.

auspumpen · #94 03-07-2011, 10:12 PM

Kurt, I can't wait to try this with the 602 pump I got from Dave a while back. I'm not sure how the tiny Garrett T2 they fit on these things will deal with more fueling, but I guess someone has to lead the way with the little fivers.

gsxr · #95 03-07-2011, 10:14 PM

Quote:

Originally Posted by auspumpen

Kurt, I can't wait to try this with the 602 pump I got from Dave a while back. I'm not sure how the tiny Garrett T2 they fit on these things will deal with more fueling, but I guess someone has to lead the way with the little fivers.

Zeitgeist was planning the same thing with his OM602 (124.128)... might be two of you blazing the 5-cyl trail soon!

auspumpen · #96 03-07-2011, 10:35 PM

My evil twin is always two steps ahead of me.

gsxr · #97 03-08-2011, 04:44 PM

I went to the dyno today - see attached graphs. Rear wheel numbers are divide numbers by 0.82 to get estimated crankshaft HP:

115hp / 160tq at wheels, uncorrected, stock IP
141hp / 201tq at wheels, uncorrected, hybrid IP
153hp / 205tq at wheels, uncorrected, hybrid IP, 350SDL turbo

140hp / 195tq at crank, uncorrected, stock IP
172hp / 245tq at crank, uncorrected, hybrid IP
187hp / 250tq at crank, uncorrected, hybrid IP, 350SDL turbo

Some comments:

1) The power curve is much better now, the shape follows the stock curve, which is good - doesn't taper off like with the KKK.

2) Boost pressure remains above 20psi to redline, which is also good. However IAT's are off the hook! Near 5000rpm I saw 300°F IAT on the dyno. Yikes! Need an IC to cool things down.

3) There is noticeable smoke at low RPM's until boost builds, then the smoke clears. It would be nice to reduce the low-RPM smoking but I'm not sure how we can do that without hurting power elsewhere.

4) Although I did all three dyno runs to an indicated 5200rpm on the tach, only one showed pulling past 5k. I'm not sure if the tach is off, or if it was a dyno operator glitch, or what. That's annoying.

5) The one run that shows pulling to 5200rpm has the power slipping at 4750 and then past 5000 it drops like a rock. I'm thinking we may need to increase the max RPM (high idle) setting to keep the governor from spoiling the party. I want the power strong to at least 5000 before it falls off, and I think we have a few hundred RPM left to play with here.

6) The power numbers are still a bit less than expected, however the performance data is pretty good, IMO. I am still using uncorrected numbers, but I included the graphs for SAE correction for grins.

My conclusions to date: The 3.5L turbo is adequate - barely - for the 6mm pump. The compressor is just a bit small to handle the high boost levels so it's superheating the intake air. A T3/T4 hybrid (or something similar) may work better? Or just a slightly larger compressor, still in T3 trim. The EGT's remained at safe levels on the dyno (~1200F peak). I forgot to bring a video camera to capture the gauge readings on the dyno, it's not easy watching four gauges (tach, IAT, EGT, boost) simultaneously and also remembering to lift off the throttle at 5200. Next time.

Still to come: Videos during an acceleration run, but that will have to wait. It's snowing outside.

compu_85 · #98 03-08-2011, 04:51 PM

So the trans and diff eat up 18% of the engine's output?

gsxr · #99 03-08-2011, 04:58 PM

Quote:

Originally Posted by compu_85

So the trans and diff eat up 18% of the engine's output?

Transmission, torque converter, belt-driven accessories (alternator, water pump, power steering, etc), and any rotational mass such as driveshaft, differential, axles, rear brake rotors, wheels, tires. It all adds up. The actual amount varies but most estimates have it in the 15-20% range. I generally stick with the 18% figure.

Kurt Smith · #**100** 03-08-2011, 05:35 PM

Quote:

Originally Posted by auspumpen

My evil twin is always two steps ahead of me.

Hehe... did you update us on the first one? Can you find more 6mm's?

babymog · #**101** 03-08-2011, 10:15 PM

That's some great info Dave, I'm watching and learning.

1stbenznc · #**102** 03-08-2011, 11:27 PM

Really great thread and info here!.... Just taking it all in and learning a lot!

I know on the diesel trucks, like my excursion 7.3L, and others, the EGT's can be dropped a couple hundred degrees quickly with the larger diameter turbo back exhausts (3" to 4" for example) I know you said that if there is more/cooler air in it will help, but the faster the exhaust can get out the cooler it will be too. It should drop the temps faster than an IC could since that is where the hot exhaust gases are backing up...., I think, right?

gsxr · #**103** 03-09-2011, 09:20 AM

If the exhaust is a restriction, yes, that will help. However at these power levels, I believe the stock exhaust should be adequate. I had checked backpressure with a gauge with the stock setup and it was zero, but I can check again for grins. The 3.5L turbo was not designed to operate at 22psi boost nor ~200hp so I still think it's at the edge of its performance envelope with my setup.

Kurt, when you have your 6mm pump built, you may want to ask if they can slightly reduce fueling at low RPM / low boost, and slightly increase fueling (?) near redline. But it really ain't bad as-is. The midrange roll-on power is sweeeeet. I'm afraid the fuel economy will suffer due to the extra layer of lead in my right foot...

Kurt Smith · #**104** 03-09-2011, 10:30 AM

Pics of SDL intake sent.

As for the low rpm smoke did you play with the ALDA yet?

winmutt · #**105** 03-09-2011, 10:44 AM

Quote:

Originally Posted by Kurt Smith

Pics of SDL intake sent.

Care to share?