Getting PowerChiped!
02-10-2011, 06:53 PM
#26
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06 R360, 06 F350 6.0, 04 CayenneS, 96 911TT 500HP, 86 928S, 74 911S, 73 914-4, 70 914-6, 02 Durrango
I don't think I ever told you guys exactly what they do for the tuning.
They advance the timing.
Lean out the ratio slightly.
Raise the electronic Torque limiter so more Torque is reached.
And a little more aggressive throttle.
Since they are not increasing the fuel to air ratio, there will be better mpg.
They do not adjust the shifting OR how the engine reacts during the shift. And they do not adjust the variable valvetrain.
They have you select an octane rating that you will use. Since my highest in my area (and state) is 91, I chose 91. MB I guess does not have their engine tuned perfectly for 91 because some owners will not get or keep like new fuel quality in the tank. So MB will de-tune their engine to, lets say 90 octane, instead of 91.
Since I chose 91, less fuel is required for a true "91 octane" fuel mixture ratio, then compared to lower octane levels like 87. That is why they lean out the mixture slightly.
I paid $350 for the tuning. I just looked on their website and it is $690. No way. Even with what I know and the experience with the tuning will I say it is worth $690. Now If you put in many miles a day, it might be worth $690... Might... $350 is very different from $690.
They advance the timing.
Lean out the ratio slightly.
Raise the electronic Torque limiter so more Torque is reached.
And a little more aggressive throttle.
Since they are not increasing the fuel to air ratio, there will be better mpg.
They do not adjust the shifting OR how the engine reacts during the shift. And they do not adjust the variable valvetrain.
They have you select an octane rating that you will use. Since my highest in my area (and state) is 91, I chose 91. MB I guess does not have their engine tuned perfectly for 91 because some owners will not get or keep like new fuel quality in the tank. So MB will de-tune their engine to, lets say 90 octane, instead of 91.
Since I chose 91, less fuel is required for a true "91 octane" fuel mixture ratio, then compared to lower octane levels like 87. That is why they lean out the mixture slightly.
I paid $350 for the tuning. I just looked on their website and it is $690. No way. Even with what I know and the experience with the tuning will I say it is worth $690. Now If you put in many miles a day, it might be worth $690... Might... $350 is very different from $690.
Last edited by smokersteve; 02-10-2011 at 07:07 PM.
02-10-2011, 10:31 PM
#27
Member
I doubt Mercedes detunes the engine because some people may put less than 91 octane into the tank. Most any modern engine of today will have a sophisticated knock sensor which retards the engine automatically if it starts to knock because of low octane gas. You could probably put midgrade 89 octane gasoline into the car every fill up without causing permanent damage. You would hurt fuel economy and performance, though.
The real advantage to designing an engine for higher octane is not to advance ignition (though that helps a little) but to allow a higher compression ratio.
Leaning out the fuel mixture would assume that Mercedes engineers can't figure out what is optimum and most efficient. Monkeying with the mixture might have worked back when engines first had emissions controls and were not tuned for power and efficiency, but I think that is long in the past.
The real advantage to designing an engine for higher octane is not to advance ignition (though that helps a little) but to allow a higher compression ratio.
Leaning out the fuel mixture would assume that Mercedes engineers can't figure out what is optimum and most efficient. Monkeying with the mixture might have worked back when engines first had emissions controls and were not tuned for power and efficiency, but I think that is long in the past.
02-12-2011, 11:39 AM
#28
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06 R360, 06 F350 6.0, 04 CayenneS, 96 911TT 500HP, 86 928S, 74 911S, 73 914-4, 70 914-6, 02 Durrango
I doubt Mercedes detunes the engine because some people may put less than 91 octane into the tank. Most any modern engine of today will have a sophisticated knock sensor which retards the engine automatically if it starts to knock because of low octane gas. I agree. I thought that the engines would adjust the the gas quality. You could probably put midgrade 89 octane gasoline into the car every fill up without causing permanent damage. You would hurt fuel economy and performance, though.
The real advantage to designing an engine for higher octane is not to advance ignition (though that helps a little) but to allow a higher compression ratio. For the fact that they can use higher compression, and the option that it will run with poor fuel, MB might actual not have the engine "FULLY"(as the powerchip man stated) tuned to 91. The engine should adjust, but there might be a safety barrier (not fully tuning the engine to 91) from MB for the people who do not take care of their car.
Leaning out the fuel mixture would assume that Mercedes engineers can't figure out what is optimum and most efficient. Im sure MB has figured out what is the best most efficient way to run the engine. But then they tune it for the probable poor fuel situations. Monkeying with the mixture might have worked back when engines first had emissions controls and were not tuned for power and efficiency, but I think that is long in the past.
The real advantage to designing an engine for higher octane is not to advance ignition (though that helps a little) but to allow a higher compression ratio. For the fact that they can use higher compression, and the option that it will run with poor fuel, MB might actual not have the engine "FULLY"(as the powerchip man stated) tuned to 91. The engine should adjust, but there might be a safety barrier (not fully tuning the engine to 91) from MB for the people who do not take care of their car.
Leaning out the fuel mixture would assume that Mercedes engineers can't figure out what is optimum and most efficient. Im sure MB has figured out what is the best most efficient way to run the engine. But then they tune it for the probable poor fuel situations. Monkeying with the mixture might have worked back when engines first had emissions controls and were not tuned for power and efficiency, but I think that is long in the past.
From what the man told me, there is room for improvement. And I feel that. Im not sure that it is ture for false that MB does not fully tune the engine to 91. But the end result I feel the difference. According to the car I am getting ~25mpg at 65mph. That was on one trip. I do not feel that it is final for the mpg testing, so next time that I drive it on the HW. I will test it, and keep testing, so I can be satisfied that it is consistent.
Last edited by smokersteve; 02-12-2011 at 11:53 AM.
