85 300SD. 9.5lb boost. Should I mess with it? - Page 2 - PeachParts Mercedes-Benz Forum

boneheaddoctor · #16 04-07-2006, 08:37 AM

Quote:

Originally Posted by Brian Carlton

I agree, however, once you get the housing open, you need a specially made and very thin 14 mm wrench to hold the shaft.

I held mine well enough with large needle nose pliers....it doesn't realy take that much to hold it. If you have any sort of a toolbox you will find something that will do the job.

Hit Man X · #17 04-07-2006, 09:04 AM

I drove my SD everywhere yesterday including some freeway jaunts... this extra boost is WONDERFUL. It doesn't really do much about town unless you're in the higher RPM area often (which I'm not often) but from a 10mph punch on the streets it's totally different.

The higher RPM pick up is there, hell the motor even sounds different underfull load.

Revert here for my initial thread - Anyone have a Manual Boost Controller?

Brian Carlton · #18 04-07-2006, 09:05 AM

Quote:

Originally Posted by boneheaddoctor

I held mine well enough with large needle nose pliers....it doesn't realy take that much to hold it. If you have any sort of a toolbox you will find something that will do the job.

Those may have worked for you, but, you can hardly rely on the torque from a neddle nose plier to secure the jam nut.

Good luck with that solution for the long term.

imdavid28 · #19 04-07-2006, 09:14 AM

Has anyone tried upgrading the turbo entirely to a larger one?

Hit Man X · #20 04-07-2006, 09:17 AM

I haven't yet as no one has really maxed that fuel pump yet, Brandon is pretty close to it.

I'd assume another T3 with a larger turbine A/R would help with higher RPM power and a larger compressor wheel to move more CFM would drop EGTs as it'd be more efficient. If you'd start to look at T3s, they came on ALL sorts of things... Volvo, Saab, etc. So you can mix/match parts or just score a new one easily for maybe $350-500 I've seen.

ConnClark · #21 04-07-2006, 11:17 AM

I investigated what might be a better match as far as turbos to go with an intercooler on an OM617. I came to the conclusion that the compressor wheel and housing from an 85 dodge daytona would be a good match. The stock turbocharger compressor on the OM617 has a trim of 45. The one for the 85 dodge dayton has a trim of 50.

go here and change the turbo maps from a t3-45 and a t3-50 map and see what I mean.

http://www.not2fast.com/turbo/glossary/turbo_calc.shtml?FeetASL=0&Tamb=21&Bore=90.9&Stroke=92.4&nCyl=5&RPM=5000&VE=65&Boost=13&Ec=60&Eic=60&PdropIC=0.5&TambIC=21&wiPercentMethanol=50&wiRate=100&wiTemp=21&SFC=0.49&AFR=13.3&maxInjectorDutyCycle=85
with an intercooler the t3-45 puts the operating point to far to the right in the choke area.

To properly size a turbo the first thing you should do before considering mixing and matching turbos is plot where your current tubo operates. Plot both of the boost levels of while maintaining steady speed and hard acceleration for lots of rpms. Then use this website to calculate the air flow in lbs/min.

I came up with the best matches of a GT-15,GT-20, or a GT-22 with an AR of .51 for a non intercooled OM617.

boneheaddoctor · #22 04-07-2006, 11:33 AM

Quote:

Originally Posted by Brian Carlton

Those may have worked for you, but, you can hardly rely on the torque from a neddle nose plier to secure the jam nut.

Good luck with that solution for the long term.

about six months and counting...I did use locktite blue going back together. The jam nut was not that awefully tight on mine. but was doing quite well having been there like that for 23 years before I disturbed it.