I Discovered Why Low Mpg And Low Hp
07-24-2005, 07:45 AM
#77
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A work of art indeed.. in that its completely unfathomable except to the original artist 
Seriously, someone crack this nut for the good of all RX8 drivers.. please come up with an ECU solution that will still allow me to pass inspection when necesary. First person to do this will have a goldmine on their hands. I don't understand how this car passes emissions what with all the fuel dumping goin' on...
Seriously, someone crack this nut for the good of all RX8 drivers.. please come up with an ECU solution that will still allow me to pass inspection when necesary. First person to do this will have a goldmine on their hands. I don't understand how this car passes emissions what with all the fuel dumping goin' on...
07-24-2005, 10:09 PM
#78
from experiance with fitting a haltech to a motor with a motronic style 60-2 trigger wheel the car can run with a number of different wireing configurations for the sensor and angle where it is trigered. in the haltech manual it states something along the lines of 'it wont run quite right' but the difference between right and wrong wasn't detectable to me. so it is possible the ecu will still work with something wrong it will just do things silightly out of sequence.
08-09-2005, 10:13 PM
#80
Originally Posted by zoom44
here is what is commonly called the trigger wheel for our cars. also known as the e-shaft position plate. remember the 20 brakes stomp reset also resets the eshaft position plate profile in the pcm memory.
Uh, 20 brakes stomp reset???!
08-10-2005, 04:56 AM
#82
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The trigger or synchronisation wheel on the Renesis engine is NOT a 60-2 teeth wheel (that's a Bosch standard), but has a more complex pattern : it's a 36 teeth wheel (teeth spaced by 10°) with 6 missing teeth at one place and 3 at another.
The tigger signal coming from the INDUCTIVE (Not Hall effect) sensor (also called Variable Reluctance Sensor) looks like this : TDC - 12 small pulse - wide synch pulse - 15 small pulses - wide synch pulse - wide synch pulse - ... (repeat)
If there was a signal problem, I guess the engine would not synchronise and probably would not start at all!
Source : MAZTECH Mazda Technician Training Manual, October 2003
The tigger signal coming from the INDUCTIVE (Not Hall effect) sensor (also called Variable Reluctance Sensor) looks like this : TDC - 12 small pulse - wide synch pulse - 15 small pulses - wide synch pulse - wide synch pulse - ... (repeat)
If there was a signal problem, I guess the engine would not synchronise and probably would not start at all!
Source : MAZTECH Mazda Technician Training Manual, October 2003
08-10-2005, 10:52 AM
#83
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Originally Posted by Rasputin
If there was a signal problem, I guess the engine would not synchronise and probably would not start at all!
I write software for a living and have done some embedded software in the past (the ECU is embedded software) so I have some experience with similar systems. A lot of whether it won't start or how bad it would run will depend on the error correction / tolerance that is programmed in. No sensors are 100% perfect so there must be some tolerance for a missing pulse. If there was was no expectation that a missing pulse could occur there would be no need for any synch pulse at all as the ECU could always assume that it's pulse count was 100% accurate.
What we don't know is the error correction just to reset the ECU's computed position when it sees a synch pulse? (i.e. the ECU thinks that it has seen 14 pulses and then the synch pulse comes along and it just goes with that) Or does the ECU keep some sort of count of how often it sees a missed pulse condition and if they occur too often (x missed pulse conditions in y revolutions) it shuts downs or goes into "limp home" mode. Or perhaps it doesn't care about a single missed pulse condition but only if it misses 2 or more pulses in a revolution. We won't know unless we get one of the Mazda software engineers posting here or somebody reverse engineers the ECU (not an easy task).
10-24-2005, 01:25 PM
#84
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Did anyone ever try this? This would be a trivial measurement for an electrical engineer (like me!) as long as you could find the sensor and probe it without a belt or pully-wheel tearing all your fingers off. Does anyone have a picture of the sensor position in the RX-8?
Fortunately for me I am getting 17+mpg with 1700 miles on my RX-8 so I'm not worried about mileage, but I am curious about the reasons behind the cars getting 12 to 13mpg.
Fortunately for me I am getting 17+mpg with 1700 miles on my RX-8 so I'm not worried about mileage, but I am curious about the reasons behind the cars getting 12 to 13mpg.
10-24-2005, 01:34 PM
#85
Originally Posted by Psylence
A 220hp car that gets no better mileage than a Ferrari Modena is just plain wrong .
My 6 speed MT is rated at 238bhp, after the downward adjustment by Mazda (from 250bhp).
Am I correct?
10-24-2005, 03:08 PM
#87
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This is all interesting. I was hoping someone would come forward having looked into this for Simo.
I average about 17.5 to 18mpg, so I frankly feel little motivation to think about getting my hands dirty.
I average about 17.5 to 18mpg, so I frankly feel little motivation to think about getting my hands dirty.
10-24-2005, 03:16 PM
#88
Bummed, but bring on OU!
Originally Posted by RotoRocket
My 6 speed MT is rated at 238bhp, after the downward adjustment by Mazda (from 250bhp).
Am I correct?
Am I correct?
10-24-2005, 08:12 PM
#90
Rotary Wanker
The sensor is located at the bottom front of the engine. Looking at the crankshaft pulley, it's right behind at the 4 o'clock position. Should have a 2 wire connector. It's only held in by one bolt. When looking at the sensor, you should also be able to see the teeth of the trigger wheel (right behind the pulley). Book says the stand alone sensor should read 950-1250 ohms at room temperature.
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