Using a zener diode to defeat the 186 mph limit
- Thread starter FloydV
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cougar694u
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Ordering a microprocessor that will read analog voltage and supply analog voltage to the ECU. Also, I'm probably going to make a gear indicator out of 6 LED's (0 for N), so you can use peripheral vision to see what gear you're in.
Read the shop manual. It says in the abstract, "Go ahead, mess with my GPS signal IN ANY WAY and off to fail/safe you go". If you install anything in between a sensor, the first electrical ping will hit the resistor/diode/tre and not the sensor values... Boom, f/safe. Wait till the loop ends with the other 2 wires getting pinged to add the signals and boom, 6fixed... Why? Each of the 3 GPS wires receive the same... the same 6fixed. That means the 186-plus signal runs the 6fixed. The 400 plus rpm signal also runs the 6fixed. Anything else tied into the GPS that uses it, runs on the 6fixed and so on. Care to follow the, ABSOLUTE theory the book says it does on the 3rd wire, or do you want to keep pulling out clutch assembies and soldering diodes to the broken bake...
Nope, sorry. no 5th map has been here since 1999. Modify the GPS, you get 6fixed only. Only the people who do not follow the abstract of the shop manual can only come up with a 5th map in their theory. It's not how the book says the bike works.
How can I walk the theory to it's conclusion in the shop manual, but for some reason, there are tons of ways to set this 186 break-out predicament. Follow the theory. Pull the GPS sensor harness connector apart. Go out and ride your 186plus and your 400rpm plus, PLUS, you get to run in the digital 6fixed, until you replug-in the sensor to return to your 5th and every other map (in the analog files) that is used when the GPS is not tampered with.
I have to know how the bike works in the abstract. I'm going to work the book theory and the clutch theory against each other. We do not have all the answers as to how this computer stuff works. For me to walk the theory in the eyes of the clutch mod, I use the shop manuals theory, then begin thinking, "in the abstract". Think Suz is going to tell you trade secrets of their computer system? I could care less. I watch the bike and how it functions. I read the manual and it reproduces the practical right there in the book. As long as the bike follows the (CODES) abstract in the shop manual (the abstract being the exact language in each square that is the written in the abstract telling you, "Since 1999, the only map ever held in place was the triggering of the 6fixed, or the book is incorrect''.
I cannot answer why hard codes do not trigger. The abstract can say, "Well,well, look at that, not a code. Oh crap, I almost missed the "practical". I felt the difference messing with that wire... let me look in the book... yep it says right here in the GPS c31... I feel 6fixed is what I feel. Let me unplug that and make sure....
If I'm not making sense of the theory in the book, show me in the abstract how the mod holds 5th. Show me how the industry standard (6fixed) since 1999 is still in use on the Busa today as well as the ZX-14, and I'll take a 'theoretical' guess that the other bike brands use the same standard issue 6fixed for their GPS equipped.
BA, What are u doing up so late?
See the special flavor butter making machine working up there? Come back in 15 minutes, I'll have the little guy squirt sam butter on yer popcorn. Or, wait around and watch him butter... Oh yeah, there he goes.... OH MAN!... he missed the tub... machine is down for a few hours before it's up and running again...
Can you call in late this morning, BA?
cougar694u
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This was the only part I understood, the rest seemed like fragmented thoughts & sentences.
With a micro controller, I can have it listen on all three wires and copy everything that's going on and send signals to the ECU that match what it's expecting, then when it picks up 6th gear, mimic what it sent for 5th gear.
Is there any way to monitor the ECU to see what gear it thinks it's in and see if it activated the failsafe?
hayabusa99b/w
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cougar694u
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The shifter positioner shaft inside the motor is grounded, so which ever land it touches is grounded. I think the black wire is there to make sure the sensor's there and not unplugged.
Since it has a center pin, the Black wire is ALWAYS grounded because it's the center land on the GPS. In Neutral, the Blue shorts to ground. So, in each gear, it grounds the Red wire with different resistances that the ECU measures.
The resistance between the different lands on the red wire when grounded are as follows:
1st = 560 Ohms
2nd = 820 Ohms
3rd = 1.5K Ohms
4th = 2.73K Ohms
5th = 6.79K Ohms
6th = 14.97K Ohms
I looked for a pattern, as far as a multiplier, but didn't find one.
**EDIT**
I forgot to add, that with this setup, the PICAXE won't work. (edited, I meant the controller, not diode).
Since it has a center pin, the Black wire is ALWAYS grounded because it's the center land on the GPS. In Neutral, the Blue shorts to ground. So, in each gear, it grounds the Red wire with different resistances that the ECU measures.
The resistance between the different lands on the red wire when grounded are as follows:
1st = 560 Ohms
2nd = 820 Ohms
3rd = 1.5K Ohms
4th = 2.73K Ohms
5th = 6.79K Ohms
6th = 14.97K Ohms
I looked for a pattern, as far as a multiplier, but didn't find one.
**EDIT**
I forgot to add, that with this setup, the PICAXE won't work. (edited, I meant the controller, not diode).
cougar694u
Registered
I did quite a bit of testing these last few days. In Neutral, the red wire (on the GPS side, pink on the harness side) has 5v on it. I measured each gear and they were close enough to the OP's values.
Now, in order for those values to hold true, the ECU supplies 8.25v with a 650 Ohm resistor in line. I used a PCB/electrical simulator to test it. It has the resistor in line so that if it shorts, it's not a direct short, and is actually more resistance than 1st gear, and therefore won't fry the ECU or that circuit.
A 10k, 11k, or 12k resistor attached from the red wire to the black wire (or any ground) will do what we're after. The 12k will make it about 4.42v; the 11k = 4.39v; 10k = 4.37v. I'd probably go with the 10k or 11k because of extra resistance presented by the oil and contact surfaces of the GPS (which may be marginal). However, this setup throws off the values slightly for each gear, but I believe them to be in tolerance (which I may be wrong).
Now, I removed the resistor and put in a 5v zener diode & 2.75k Ohm resistor across the black & red wire (see attached) and the values for first through fourth were on line; 5th was slightly low at 4.18v; but 6th was at 4.4v. I tried a 3k resistor and it put 6th at 4.43v and 5th at 4.20v; 2.5k put 6th at 4.37v and 5th at 4.14.
In the attached, you see the GPS (SW1 at the top) with 6 positions (didn't have 7 for N, but it's a different wire anyway). It's currently measuring voltage there in 6th gear with the zener diode and 2.75k Ohms resistor. R1-R6 represent gears 1-6, and they all connect to a common (ground). You can use the black wire, the chassis, or any other ground, but I had to create a loop, and used a battery in the diagram with 40 Ohms resistance (that's what I measured between the blue & black while in neutral). It starts at B1 and goes to R7, which is basically the signal from the ECU, then to the switch. You can see where i hooked the diode & resistor from the common to the red/pink wire.
When in Neutral, both the 10-12k resistor and the zener diode showed about 4.6v. While reading the FSM, it says that as long as the ECU sees voltage > 0.6v for 3 seconds, it won't throw the code.
The resistor must go between the red/pink wire and the diode. If it goes between the ground and the diode, it throws off first & second.
This is the simple way. The harder way is to build a relay that opens the zener diode circuit when the blue wire is grounded. I'll work on that later...
**EDIT**
Using a 4.3v zener diode with no resistor caused some pretty wack values in the simulator (2-6 were like 2.4v, 1 was like 1.9v).
Now, in order for those values to hold true, the ECU supplies 8.25v with a 650 Ohm resistor in line. I used a PCB/electrical simulator to test it. It has the resistor in line so that if it shorts, it's not a direct short, and is actually more resistance than 1st gear, and therefore won't fry the ECU or that circuit.
A 10k, 11k, or 12k resistor attached from the red wire to the black wire (or any ground) will do what we're after. The 12k will make it about 4.42v; the 11k = 4.39v; 10k = 4.37v. I'd probably go with the 10k or 11k because of extra resistance presented by the oil and contact surfaces of the GPS (which may be marginal). However, this setup throws off the values slightly for each gear, but I believe them to be in tolerance (which I may be wrong).
Now, I removed the resistor and put in a 5v zener diode & 2.75k Ohm resistor across the black & red wire (see attached) and the values for first through fourth were on line; 5th was slightly low at 4.18v; but 6th was at 4.4v. I tried a 3k resistor and it put 6th at 4.43v and 5th at 4.20v; 2.5k put 6th at 4.37v and 5th at 4.14.
In the attached, you see the GPS (SW1 at the top) with 6 positions (didn't have 7 for N, but it's a different wire anyway). It's currently measuring voltage there in 6th gear with the zener diode and 2.75k Ohms resistor. R1-R6 represent gears 1-6, and they all connect to a common (ground). You can use the black wire, the chassis, or any other ground, but I had to create a loop, and used a battery in the diagram with 40 Ohms resistance (that's what I measured between the blue & black while in neutral). It starts at B1 and goes to R7, which is basically the signal from the ECU, then to the switch. You can see where i hooked the diode & resistor from the common to the red/pink wire.
When in Neutral, both the 10-12k resistor and the zener diode showed about 4.6v. While reading the FSM, it says that as long as the ECU sees voltage > 0.6v for 3 seconds, it won't throw the code.
The resistor must go between the red/pink wire and the diode. If it goes between the ground and the diode, it throws off first & second.
This is the simple way. The harder way is to build a relay that opens the zener diode circuit when the blue wire is grounded. I'll work on that later...
**EDIT**
Using a 4.3v zener diode with no resistor caused some pretty wack values in the simulator (2-6 were like 2.4v, 1 was like 1.9v).
cougar694u
Registered
I scrounged a 6.2v zd out of a power supply I had laying around and combined it with a 2k Ohm resistor (measured at an actual 1.953k Ohm).
According to the simulator, it'll yield these voltages:
1 = 1.81
2 = 2.33
3 = 3.10
4 = 3.68
5 = 4.18
6 = 4.39
Now to take it home a build it on the breadboard with the GPS and see if simulated is close to actual.
According to the simulator, it'll yield these voltages:
1 = 1.81
2 = 2.33
3 = 3.10
4 = 3.68
5 = 4.18
6 = 4.39
Now to take it home a build it on the breadboard with the GPS and see if simulated is close to actual.
cougar694u
Registered
okay, that circuit with the 6.2v zd & resistance didn't work (which I expected), so I requested some samples from fairchild, and they're sending me 3 4.3v zd's.
FLZ4V3A DIO ZENER 0.5W 4.07-4.23V SOD80
FLZ4V3B DIO ZENER 0.5W 4.22-4.38V SOD80
FLZ4V3C DIO ZENER 0.5W 4.35-4.52V SOD80
I have a feeling that this won't work since the ECU looks at resistance, but there's only one way to find out...
FLZ4V3A DIO ZENER 0.5W 4.07-4.23V SOD80
FLZ4V3B DIO ZENER 0.5W 4.22-4.38V SOD80
FLZ4V3C DIO ZENER 0.5W 4.35-4.52V SOD80
I have a feeling that this won't work since the ECU looks at resistance, but there's only one way to find out...
cougar694u
Registered
After testing, the above listed ZD's dropped the voltage too much, even the 'C'. I also had BZX79C4V3, which is a 4.3v ZD, that I tested. It also dropped voltage too much, but with 2k Ohms resistance, it was right on the money. Since it did have the 2k Ohms resistance, it lowered the voltages slightly 1-4, a little more in 5th, and capped 6th to appear like 5th.
I also tested the 12k Ohm and the results were almost exactly the same as the ZD. I may try to get my hands on a 4.7v ZD to test with and see if it alone works.
I also tested the 12k Ohm and the results were almost exactly the same as the ZD. I may try to get my hands on a 4.7v ZD to test with and see if it alone works.
Just a thought.... Could a subminiature relay circuit be tuned to close at the higher 6th gear position voltage and send the 5th gear resistance via a fixed resistor to the ECU?
Would the neutral position still cause a problem? Could the neutral light circuit be used to disable the relay circuit when the bike is in neutral?
Would the neutral position still cause a problem? Could the neutral light circuit be used to disable the relay circuit when the bike is in neutral?
cougar694u
Registered
I thought about that, but here's what I think might happen (this is just speculation):
If you have some relay or controller monitoring for any voltage above 4.45v and ground through 6.79K Ohms resistance whenever it does find that, then the wire you're monitoring (red or pink) will drop to ~4.38v. When it drops to the 5th gear voltage, it will deactivate the relay, which will then provide ~4.7v and activate the relay, thus putting you in a death loop until you're physically back in 5th gear.
And yes, when in Neutral, it will activate the relay, but you could have it deactivate when the neutral wire is grounded.
I'm sure there are ways around it, and yes, I'm thinking of them, but until I have something worth bring up, they'll stay in my melon.
If you have some relay or controller monitoring for any voltage above 4.45v and ground through 6.79K Ohms resistance whenever it does find that, then the wire you're monitoring (red or pink) will drop to ~4.38v. When it drops to the 5th gear voltage, it will deactivate the relay, which will then provide ~4.7v and activate the relay, thus putting you in a death loop until you're physically back in 5th gear.
And yes, when in Neutral, it will activate the relay, but you could have it deactivate when the neutral wire is grounded.
I'm sure there are ways around it, and yes, I'm thinking of them, but until I have something worth bring up, they'll stay in my melon.
Good point cougar....
I guess if I were really interested in this mod, I would simply try installing a single pole, double throw thumb switch near the handgrip.
Position 1 would be stock
Position 2 would just disconnect the the sensing wire and run it through a 6.79k resistor to ground
Sorta like a nitrous switch for 6th gear
I guess if I were really interested in this mod, I would simply try installing a single pole, double throw thumb switch near the handgrip.
Position 1 would be stock
Position 2 would just disconnect the the sensing wire and run it through a 6.79k resistor to ground
Sorta like a nitrous switch for 6th gear
cougar694u
Registered
More or less, that'd be an easy route, and is basically the concept of a 'switchable' TRE. I explained this in the "Since 1999 A Busa codes to c31 6Fixed, Why the clutch mod will do nothing" thread, but don't even bother to read through it, as you may lose some IQ points.
You could also use the switch in any gear to tell the ECU it's in 5th gear.
You could also use the switch in any gear to tell the ECU it's in 5th gear.
Yea, I have been kinda following the "since 1999" thread and no offense to 2Busa but where is he getting the picture that the GPS is a god-like component married to the ECU? Does the GPS actually have logic circuitry in it (can it read and/or convey digital info from/to the ECU) or is it simply a resistor bank connected to switches on the shifter?
cougar694u
Registered
It's a resistor pack with multiple lands. When shifting, the rod inside grounds a different resistor for each gear. It's that simple, nothing else.
cougar694u
Registered
Made the circuits and they're ready to test.
From left to right:
Zener Diode with 2k Ohm resistance; MGPS Simulation (should be 4.67k, actual was ~2% less); 12k Ohm resistance; 5th gear simulation (should be 6.79k, actual was 6.64k, or 2.2%)
Now I need to get on the dyno.
I should also note that it's a 4.3v ZD, where next week I'll order a 4.7v and test before going to the dyno.
View attachment Image003.jpg
From left to right:
Zener Diode with 2k Ohm resistance; MGPS Simulation (should be 4.67k, actual was ~2% less); 12k Ohm resistance; 5th gear simulation (should be 6.79k, actual was 6.64k, or 2.2%)
Now I need to get on the dyno.
I should also note that it's a 4.3v ZD, where next week I'll order a 4.7v and test before going to the dyno.
View attachment Image003.jpg
Cougar,
I've been away for a while. What have you decided?
If you think you have the final answer, how about a schematic (or step by step) to build the "ultimate" de-restrictor?
It seems to me that you are close to a solution. I'd love to build your answer. If I can build and duplicate your results, I'll make more than one and give the extras to members to try. It would really be nice to have an electrical solution and know the reasoning behind it, and to be able to see the components and not someone's buried-in-epoxy secret that might or might not work as expected.
