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+--- Thread: OM605 Crazy Waste gate Control (/showthread.php?tid=8057)
OM605 Crazy Waste gate Control - Symondo - 05-25-2018
Hi All, New here and first post/thread.
I have a 98 W202 OM605 daily driver which I am attempting to make more safe for my wife to drive. It became so under powered as of late that she refused to drive it. It is generally a death trap at intersections because of the poor throttle response. You almost need a 'Precog' approach to driving by pressing the throttle well in advance of the traffic maneuver you wish to attempt.
Anyway. Several problems have been solved.
1. The catalytic converter was almost completely blocked. I took a pressure tap ahead of the converter and found under load could easily see 15psi @ 3000rpm which was my gauge limit.
The cat was removed which trippled my upper end response and power.
2. EGR had been removed alog time ago so decided to do a direct route of cooler piping direct to the manifold. this further improved turbo response.
But low end throttle response is still poor / al be it a little improved. I have read here that some claim a stage 1 Remap greatly improves initial response so hope to do this also. Hoping 'Seanyt' can help there.
But but..... quite some time a go i noticed weird turbo spooling that seemed to have to re-spool through each gear change. It seemed very odd to me and thought 'Surely not'. I attached a vacuum gauge between the waste gate control solenoid and actuator to see what was going on. And yes the ECU is opening the wastegate through every gear change forcing pressure loss and respool of the turbo. Grrrr.
and why????I cannot make sense of why Mercedes would control the wastegate like this. Surely not to reduce clutch pack / band forces in the transmission. Maybe to soften the gear changes so that the sunday driver will feel less through the gear change? Who Knows?
This does not appear to be unique to my vehicle as my brother has the station wagon version (Estate) which does the same crazy thing.
My question is. Will a stage 1 remap get rid of this crazy waste gate control? Or am i forced to go mechanical control?
I think a remap is the best way forward regardless but interested if the is any change to waste gate madness?
RE: OM605 Crazy Waste gate Control - starynovy - 05-25-2018
Can be remaped that way. Also upping idle speed and adding more off-boost fuel makes it whole lot more driveable. I would say reactions are twice as fast. Bare stock is just painful to drive, mercedes done fuck up on calibrations with this engine. If someone disassembled ECU code it would be possible to make it bark like M-pump.
RE: OM605 Crazy Waste gate Control - Symondo - 05-26-2018
Starynovy, I see you have had a C250TD in the past, @ 160kw was that on the stock turbo? Just wondering if you experienced the same waste gate opening through gear changes, Obviously you had it remapped. Was that attribute gone afterwards?
RE: OM605 Crazy Waste gate Control - starynovy - 05-28-2018
Did it as tobulus from here suggested. Turned off boost deviation error and set whole map to desired boost. That way it will not open on gear change. Mercedes did it for fuel consumption where while cruising there is just enough boost to burn clean compared to plain mechanical WG which boosts all the time. I think they saw this problem but that prehistoric ecu might be too stupid to ignore sudden gear change and open turbo on prolonged cruise so they leave it be..after all its car for old dentists.