Mazda Makes Another Statement About Hp Loss
09-25-2003, 12:27 PM
#11
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Join Date: Sep 2002
Location: teh frozen nort
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All I was saying is that with the new cars it is often very difficult to get a true reading on the chassis dyno. I don't know if you read the SCC article on the EvoVIII vs. M3, 911, and S4 - they were going to list hp numbers but with both the M3 and the 911 the electronics got all confused and they were not able to get a true reading, because the car was trying to correct for a situation that it perceived as locked front wheels.
I agree the bit about rich mixtures/retarded timing under full load smells a bit like an excuse.
J
I agree the bit about rich mixtures/retarded timing under full load smells a bit like an excuse.
J
09-25-2003, 02:14 PM
#12
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Join Date: Dec 2002
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Perhaps the load on the engine is not truely comparable to the load on a dyno. When the ECU sences this load difference it compensates for it buy retarding/richening.
thats what i got out of the statement.
thats what i got out of the statement.
09-25-2003, 05:41 PM
#13
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Join Date: May 2003
Posts: 15
Originally Posted by mazdadrifter' date='Sep 25 2003, 03:57 AM
when the PCM determines unusual operating parameters such as excessive slip in the drivetrain from the front to the rear wheels, it causes a rich high-RPM mixture and retardation of the timing.
09-25-2003, 07:30 PM
#14
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Join Date: Oct 2002
Location: Perth, Western Australia
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OEM is a balancing act: keep the rotorheads happy with a gutsy engine as expected, and keep legislators happy with low emmissions
Anyone who has played with a rote has farked up the tune at some point. The rich mixtures & retarded spark are not for the engines benefit. Lean mixtures give high exhaust temp & high oxides of Nitrogen in the exhaust.....There is more mention of the protection of the catalyst than anything else. Reading between the lines.....all these steps are to protect the emmissions system.
In the case of a 20B Cosmo, there is a rich/retarded trough in the fuel/ign maps of the factory computer to allow the engine to pass the 3000rpm emission test! I doubt they would dare to use that kind of creativity these days. It only worked when they were brand spanking too, I have bought a 20B JC from Japan that failed the roadworthy on emmissions
Anyone who has played with a rote has farked up the tune at some point. The rich mixtures & retarded spark are not for the engines benefit. Lean mixtures give high exhaust temp & high oxides of Nitrogen in the exhaust.....There is more mention of the protection of the catalyst than anything else. Reading between the lines.....all these steps are to protect the emmissions system.
In the case of a 20B Cosmo, there is a rich/retarded trough in the fuel/ign maps of the factory computer to allow the engine to pass the 3000rpm emission test! I doubt they would dare to use that kind of creativity these days. It only worked when they were brand spanking too, I have bought a 20B JC from Japan that failed the roadworthy on emmissions
09-25-2003, 07:32 PM
#15
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Join Date: Feb 2002
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sounds like a good way to shut people up about the engine dyno numbers, but where is the real fact numbers about a car that weighs 2900lbs with the power its supposed to have, I know it has no torque but it should still be quicker no?
09-25-2003, 07:45 PM
#16
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Join Date: Oct 2002
Location: Perth, Western Australia
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True too. In the States cars seem to be promoted on power.
No mention of power is made in the Rx8 propaganda here. Saves embarrassment later!
There is one solution: get one to a track with a good driver & pull some 1/4's! The 'weight shifted horsepower' calc is never far wrong!
No mention of power is made in the Rx8 propaganda here. Saves embarrassment later!
There is one solution: get one to a track with a good driver & pull some 1/4's! The 'weight shifted horsepower' calc is never far wrong!
09-26-2003, 05:42 PM
#18
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Join Date: Apr 2002
Location: NASA/JSC - Clear Lake, TX
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Originally Posted by Robbomaz' date='Sep 25 2003, 06:45 PM
There is one solution: get one to a track with a good driver & pull some 1/4's! The 'weight shifted horsepower' calc is never far wrong!
http://rotarynews.com/view.php?id=208
