M tune install.
#16
I will have mine installed soon... currently my car is about halfway back together after a rod bearing / oil pan gasket replacement... decided to do ball joints and rework my engine harness while I'm in there, so it's taken a little longer than expected. Hopefully my kit will arrive soon so I can tie all the wiring through the snorkel before putting the harness back in.
#18
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Exactly the case.
In order for the processor in the DME to understand analog inputs, there is an IC called an ADC (analog to digital converter). This IC takes a 0-5 volt signal and outputs a 0-255 digital value to the processor.
This ADC has 8 channels, or 8 inputs/outputs if you prefer. In factory form, 7 of these are used: AFM, Battery Voltage, AIT, Coolant, Altitude Sensor, Idle/WOT switch, FQS. There is only one unused channel. This channel reads the input from pin 28 on the DME. The factory wiring harness simply ties this to ground, and the DME never really uses it. By making use of this unused channel, we can add functionality to the DME without sacrificing any of the normal ADC inputs.
Moreover, this unused channel has a voltage bias applied to it. The DME typically does this in order to read resistance based sensors, such as the AIT or coolant temp. However, a MAP sensor is not a resistance based sensor, rather it outputs a voltage signal. To keep the two voltage signals from conflicting the voltage bias needs to be removed. Cutting resistor will open the voltage supply circuit, allowing the MAP sensor signal to be undisturbed - this is a necessity.
Simply put, there is really only one way to skin this cat.
In order for the processor in the DME to understand analog inputs, there is an IC called an ADC (analog to digital converter). This IC takes a 0-5 volt signal and outputs a 0-255 digital value to the processor.
This ADC has 8 channels, or 8 inputs/outputs if you prefer. In factory form, 7 of these are used: AFM, Battery Voltage, AIT, Coolant, Altitude Sensor, Idle/WOT switch, FQS. There is only one unused channel. This channel reads the input from pin 28 on the DME. The factory wiring harness simply ties this to ground, and the DME never really uses it. By making use of this unused channel, we can add functionality to the DME without sacrificing any of the normal ADC inputs.
Moreover, this unused channel has a voltage bias applied to it. The DME typically does this in order to read resistance based sensors, such as the AIT or coolant temp. However, a MAP sensor is not a resistance based sensor, rather it outputs a voltage signal. To keep the two voltage signals from conflicting the voltage bias needs to be removed. Cutting resistor will open the voltage supply circuit, allowing the MAP sensor signal to be undisturbed - this is a necessity.
Simply put, there is really only one way to skin this cat.
#21
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Gents, I am grateful to anyone willing to put time and effort into these mostly forgotten cars, and fear my comment did not come across as intended. I did not by any means intend to imply that Josh did anything other than his own work -- I have zero basis to suggest that, and am sure he has worked tirelessly on this. It was an off the cuff reaction when I saw how similar the two MAP sensors get installed. I'll delete it out of respect to my 944 brethren and vendors...
#22
Three Wheelin'
What the deuce is it with almost everyone who has a first gen MAF kit, also has their cars in pieces?!!
Rogue, any idea when the retail kits will be released? I'm guessing you're waiting on results from guys who have the kit right now. But with lots of guys in the field with their cars down, I'm guessing it won't be very soon (next month or two) before we see the retail kits?
Rogue, any idea when the retail kits will be released? I'm guessing you're waiting on results from guys who have the kit right now. But with lots of guys in the field with their cars down, I'm guessing it won't be very soon (next month or two) before we see the retail kits?
#23
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Apparently those of us with our cars all tore apart right now are the same people who kept up with Joshua's recent progress with his MAF kit and jumped at the chance to get on the pre-order list. It's all about timing and taking quick action.
#24
Three Wheelin'
So now people who have their cars together, and could be giving feedback to Josh are waiting around for those with their cars in pieces. That's sounds like bad timing to me...
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Yep, pretty much all the kits in the first round went to people who either aren't common rennlist posters, or people in the middle of their projects...
I will be able to do another round very soon
I've also picked up a 944NA, so I can finish the SD-Tune kit, and am working on finishing the piggyback... Even if I'm quite, it doesn't mean I'm not working on stuff
I will be able to do another round very soon
I've also picked up a 944NA, so I can finish the SD-Tune kit, and am working on finishing the piggyback... Even if I'm quite, it doesn't mean I'm not working on stuff
#27
hard to give feedback on a product when you don't even have possession of said product yet.. I think you need to relax.
#28
Wax On, Wax Off
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What the deuce is it with almost everyone who has a first gen MAF kit, also has their cars in pieces?!!
Rogue, any idea when the retail kits will be released? I'm guessing you're waiting on results from guys who have the kit right now. But with lots of guys in the field with their cars down, I'm guessing it won't be very soon (next month or two) before we see the retail kits?
Rogue, any idea when the retail kits will be released? I'm guessing you're waiting on results from guys who have the kit right now. But with lots of guys in the field with their cars down, I'm guessing it won't be very soon (next month or two) before we see the retail kits?
#29
Three Wheelin'
Anyways, I'll have to go have one of these . That ought to calm me down.
#30
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Don't worry too much... even us guys with our "cars in pieces" don't have a kit yet. Only the pre-release testers have M-Tune installed in their cars. There hasn't been any time lost yet, but the timer will start counting soon b/c I've heard that my kit is "in the mail".