Stage 2 - what does it do ???
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Joined: May 2002
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Stage 2 - what does it do ???
Hello Guys,
Does anyone know by setting to Stage 2 , what is ACTUALLY (physically) being altered ???
MB's ECU is supposed to be Adaptive, so shouldn't the ECU self-adjust itself after few hundered miles regardless of what Stage it was set to ???
Regards
Does anyone know by setting to Stage 2 , what is ACTUALLY (physically) being altered ???
MB's ECU is supposed to be Adaptive, so shouldn't the ECU self-adjust itself after few hundered miles regardless of what Stage it was set to ???
Regards
MBWorld Fanatic!
Joined: Nov 2001
Posts: 6,211
Likes: 2
From: Laguna Niguel, CA
The ECU runs in two possible modes. The most common is closed loop mode where the ECU gets feedback to make air/fuel ratio decisions based on sensors like the O2 sensor and MAF sensor. This is fully adaptive up to a point but if that point is reached it would likely throw a code and may turn your Malfunction Indicator Light on (Check Engine). There are certain circumstances where the ECU can't depend on the input from these sensors so it runs on a fixed set of parameters and this is refered to a open loop mode. This is likely when you first start the car and the O2 sensor hasn't warmed up or at full throttle when the input from these sensors is not quick enough to react so the ECU just has a table of pulse widths for the fuel injectors that are fixed based on other known sensors like the tach.
Now you want to know what Stage 1|2|3 does on the fuel corrective screen on the DAS programmer. I don't think anyone knows for sure (other than the MB engineers that work on it). The theory is that it modifies open loop fuel injector pulse widths to enrichen the fuel mixture. I have my car set to Stage 2 to compensate for the extra boost from my ASP pulley, the K&N filter and the soon to be installed Renntech muffler. Keep in mind that this does not have any effect during closed loop mode at part throttle.
Now you want to know what Stage 1|2|3 does on the fuel corrective screen on the DAS programmer. I don't think anyone knows for sure (other than the MB engineers that work on it). The theory is that it modifies open loop fuel injector pulse widths to enrichen the fuel mixture. I have my car set to Stage 2 to compensate for the extra boost from my ASP pulley, the K&N filter and the soon to be installed Renntech muffler. Keep in mind that this does not have any effect during closed loop mode at part throttle.
Super Member
Joined: Dec 2002
Posts: 560
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From: FL
2000 S500 Brilliant Silver, 1990 BMW 735iL, 1971 Pontiac Trans Am 455 HO, 1976 Pontiac Formula 400
ignition setting
Buellwinkle, have you also reset you corrective ignition setting to 93 RON? Do you know if this is a performance enhancement?
I have reset the ignition as described in my 2000 S class, but not the fuel stage. Should I also change the fuel setting if available?
Thanks in advance.
I have reset the ignition as described in my 2000 S class, but not the fuel stage. Should I also change the fuel setting if available?
Thanks in advance.
MBWorld Fanatic!
Joined: Apr 2002
Posts: 1,256
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From: Melbourne, Australia
E55, F550, S600 Ducati 999
Contrary to popular opinion, setting the fuel setting to 93RON is NOT a performance enhancement. This setting retards the ignition curve from BASE. The BASE setting is for 95RON fuel. These are Euro not US measurements. In the US you use PON (pump octane number). From memory 95RON is equal to US 91PON. 93RON is equal to US 89PON. These settings are provided to retune the car to work with poor quality fuel, not enhance performance.
