NOS1290
Expert Class
Posts: 103
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posted October 23, 2006 04:28 PM
High Speed Enrichment - How does it work?
I have been mapping my '01 1290 for 2 years with a datalogger, and have always noticed that the air/fuel starts to drop around 4th gear. If the map is tuned at 13.5:1 in 4th, it is usually running almost 14:1 in 2nd or 3rd. I usually adjust for 4th gear conditions (13.5:1) every time I go to the track.
My understanding has always been that the MAP sensors tell the computer to add fuel as the speed and manifold air pressure builds. I dont exaclty know what the GPS (gear position sensor) does. I don't think it pulls timing or changes fuel like it does on the Busa, but I'm not certain.
Recently (this week) she started leaning out in 4th gear a bunch, instead of going a bit rich. ?? I added a bit of fuel to keep 4th at 13.5, but now I'm WAY rich (11:1)in lower gears. I need to debug this but don't know enough about the design. How does it work?
-Is the ECU looking at gear position.
-Can you trick the GPS into showing 4th gear all the time.
-Can a pressure sensor go bad and not throw a code?
Has this happened to anyone and they actually have been logging it?
  
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thekaz
Needs a job
spell chequer is bustimicated
Posts: 2909
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posted October 23, 2006 05:04 PM
quote:
I have been mapping my '01 1290 for 2 years with a datalogger, and have always noticed that the air/fuel starts to drop around 4th gear. If the map is tuned at 13.5:1 in 4th, it is usually running almost 14:1 in 2nd or 3rd. I usually adjust for 4th gear conditions (13.5:1) every time I go to the track.
My understanding has always been that the MAP sensors tell the computer to add fuel as the speed and manifold air pressure builds. I dont exaclty know what the GPS (gear position sensor) does. I don't think it pulls timing or changes fuel like it does on the Busa, but I'm not certain.
Recently (this week) she started leaning out in 4th gear a bunch, instead of going a bit rich. ?? I added a bit of fuel to keep 4th at 13.5, but now I'm WAY rich (11:1)in lower gears. I need to debug this but don't know enough about the design. How does it work?
-Is the ECU looking at gear position.
-Can you trick the GPS into showing 4th gear all the time.
-Can a pressure sensor go bad and not throw a code?
Has this happened to anyone and they actually have been logging it?
not sure about the other stuff but for sure the sensor can become slow or sticky without setting a code. it happens on vehicle map sensor ALL the time
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ridgeracer
Pro
Posts: 1309
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posted October 23, 2006 08:55 PM
 Edited By: ridgeracer on 23 Oct 2006 21:57
I've been looking at the ECU software and I can tell you that the ECU most definetly uses the gear position inputs in calculating the final injector value. So far I have found 6 different sections of the code that use the gear position to select which map data set will be used in calculating intermittent variables that effect injector timing.
I am not at the point yet where I can tell you that given a set air temp/pressure and gear setting the A/F is adjusted plus or minus X amount. But I did notice something interesting looking at the raw Map data.
It appears that map makes some unique adjustment for 4th gear. 4th may not be the best gear to use as your refrence. Other gear data shows that 5th and 6th also get special treatment.
To your other question, it is very easy to trick the ECU into thinking it is in 4th gear (or any gear) all the time. Here is a rough idea of what you need to do. This drawing is for 6th always but could easily be made for 4th always. It gives the basic idea.
http://www.olympus.net/personal/mbially/zx14-gear-5.pdf
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NOS1290
Expert Class
Posts: 103
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posted October 24, 2006 12:47 AM
Kind of interesting since most of us dyno tune a bike initially in 4th (or 5th). Has anyone noticed a difference in wiring the bike in a higher gear setting. Its one of the first things you do to a Busa, but thats to get around speed limiter and to get full ignition advance.
Still baffled as to how to debug this problem. Need to look at the pressure sensor(s) in the tail and the airbox first.
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psycho1122
Pro
Posts: 1608
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posted October 24, 2006 06:06 AM
NOS1290; Question......What type of snorkel are you running?
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You say PSYCHO like it's a BAD thing!!
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Johnnycheese
Pro
Posts: 1008
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posted October 24, 2006 06:24 AM
just remember a 12 has two sensors for pressure. one for atomsphere and one in the air box for pressure
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Builder and tuner of some of the fastest N.A. and P/A Hayabusas and ZX12 /14 in Texas
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thekaz
Needs a job
spell chequer is bustimicated
Posts: 2909
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posted October 24, 2006 07:29 AM
quote:
I've been looking at the ECU software and I can tell you that the ECU most definetly uses the gear position inputs in calculating the final injector value. So far I have found 6 different sections of the code that use the gear position to select which map data set will be used in calculating intermittent variables that effect injector timing.
I am not at the point yet where I can tell you that given a set air temp/pressure and gear setting the A/F is adjusted plus or minus X amount. But I did notice something interesting looking at the raw Map data.
It appears that map makes some unique adjustment for 4th gear. 4th may not be the best gear to use as your refrence. Other gear data shows that 5th and 6th also get special treatment.
To your other question, it is very easy to trick the ECU into thinking it is in 4th gear (or any gear) all the time. Here is a rough idea of what you need to do. This drawing is for 6th always but could easily be made for 4th always. It gives the basic idea.
http://www.olympus.net/personal/mbially/zx14-gear-5.pdf
hey ridge doesn't brain hurt alot from holding all that kind of awesome info & skills inside it 
It is a great graph but why fourth gear ?? The four gearset isnt that much taller than any other ??
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shiphteey
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Posts: 2529
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posted October 24, 2006 07:39 AM
Maybe its all in my head but 4th gear is REALLY when the 12 starts to wake up and walk a busa (right after the 1/4 mile).
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dougmeyer
Needs a job
moderated
Posts: 2713
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posted October 24, 2006 10:05 AM
4th gear is about when the ram air pressure starts to be significant.........
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psycho1122
Pro
Posts: 1608
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posted October 24, 2006 12:24 PM
quote:
4th gear is about when the ram air pressure starts to be significant.........
This is also where you will start to loose ram pressure if you are using the Hans or other type of snorkel that has too large an opening. This will promote the ECU to lean you out.
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You say PSYCHO like it's a BAD thing!!
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NOS1290
Expert Class
Posts: 103
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posted October 24, 2006 05:06 PM
I use the stock ram air system with the resonators in place. Never saw a difference with or without. I think I'm geared to pull about 154 in 4th at 12.3k (extended). I have always previously seen the motor richen up a bit in 4th, but now it leans out.
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TRNorBRN6001
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Posts: 2021
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posted October 24, 2006 06:49 PM
Hope Entropy Data Logs his air box pressure at the Texas Mile. Should be interesting. It would also be interesting to see the difference between Hans and OEM at 200mph.
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TFA 200MPH CLUB MEMBER!
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psycho1122
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posted October 25, 2006 06:27 AM
Oh yeah! It is very interesting!! 
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zrexpilot
Expert Class
Posts: 470
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posted October 25, 2006 07:12 PM
You cant just tie gear wires together and trick the ecu into thinking it in another gear. A given gears output voltage is zero, and not in gear is a given voltage.
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ridgeracer
Pro
Posts: 1309
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posted October 26, 2006 07:22 AM
All you need to do is unplug the gear selector and jump the correct gear wire to ground (on the plug attached to the wire harness)
See the pdf file in my post above for an example schematic
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supra5677
Pro
Posts: 1279
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posted October 26, 2006 07:40 AM
anybody try the larger flowing 04-05 injectors when tuning and see any difference?
How do we get are bikes to make peak power at 11625, like many zx11's do with jetting and muzzy exhaust? EVERY chart Ive ever seen for the 12r table tops between 10,000 something to the limiter.. Is this a fuel thing? Or ECU thing?
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thekaz
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spell chequer is bustimicated
Posts: 2909
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posted October 26, 2006 08:09 AM
quote:
You cant just tie gear wires together and trick the ecu into thinking it in another gear. A given gears output voltage is zero, and not in gear is a given voltage.
actually you can becuase the ECU is simly looking for a ground path or 0v on a specific wire to tell itself what gear it is in. So if you ground sixth gear for example the ecu will ALWAYS think the bike is in sixth.
Ridge's wiring diagram is a simple solution for these ZX12's that use a ground switching gear selector
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entropy
Moderator
Posts: 8671
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posted October 26, 2006 10:27 AM
THIS is a VERY cool thread!
First thing i'm gonna do is start having the dyno guy do 5th gear pulls.
I will be logging MAP at the mile, but i have my OEM snorkle on (not Hans). The Hans doesn't provide the rigidity for the nose that the OEM one does.
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TRNorBRN6001
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posted October 26, 2006 10:33 AM
I hear that, especially when your low and pop the fender!
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psycho1122
Pro
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posted October 26, 2006 11:07 AM
I have seen 4 more peak H.P. on the dyno in 5th vs. 6th gear... 
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NOS1290
Expert Class
Posts: 103
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posted October 26, 2006 03:28 PM
Any ideas on why the enrichment circuit is NOT working. Again, the motor is getting leaner at speed; not richer as designed. I was going to look at GPS sensor and the two air pressure sensors for defects. I suppose the muzzy fuel pump could be defective. Not sure how to check that without buying a fuel pressure sensor and logging it.
BTW Supra, in my experiences the fuel injectors are not the limiting factor on these motors. The heads and cams are. My motors power levels off and stays flat from 11400 all the way to 12450 (extended ECU) on stock injectors. The cams on these motors are tiny.
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zrexpilot
Expert Class
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posted October 26, 2006 04:55 PM
quote:
All you need to do is unplug the gear selector and jump the correct gear wire to ground (on the plug attached to the wire harness)
See the pdf file in my post above for an example schematic
I can see that working. The very first shcematic. the rest will not work. You tied all gears in to sixth so sixth would always be recievng voltage while 12345 wil be getting no voltage. So the ecu will think its in 12345 gear.
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zrexpilot
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posted October 26, 2006 07:38 PM
actually now that I think about, not even the first schematic will work. The ECU does not have any input voltages from any gear's so it will think it is in all gears, this will do nothing but screw it up and probably go into failsafe mode, or who knows what.
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zrexpilot
Expert Class
Posts: 470
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posted October 26, 2006 08:02 PM
quote:
quote:
You cant just tie gear wires together and trick the ecu into thinking it in another gear. A given gears output voltage is zero, and not in gear is a given voltage.
actually you can becuase the ECU is simly looking for a ground path or 0v on a specific wire to tell itself what gear it is in. So if you ground sixth gear for example the ecu will ALWAYS think the bike is in sixth.
Ridge's wiring diagram is a simple solution for these ZX12's that use a ground switching gear selector
But it also looking for a voltage from the other gears that it is not in.
So when it's in 6 th 12345 wil have a voltge to the ECU and 6th will be zero.
Those diagrams will not work.
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ridgeracer
Pro
Posts: 1309
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posted October 26, 2006 08:31 PM
I must disagree with you. If you look at the internal ECU circuit you will see why.
http://www.olympus.net/personal/mbially/ecu_internal_gear.pdf
Inside the ECU the six gear input lines go to a resistor voltage divider network that reduces the gear selection to a single voltage that is read by one of the CPU's analog channels.
If none of the six gears is grounded then resistor R414 pulls the signal to +5V or 100% which the ECU software reads as no gear selected condition. If however the bike is in first gear then the voltage is divided by the resistors R407 (390 ohms) to ground and R414 (1000 ohms) to +5V. The voltage to the CPU will be somewhere between 5V and ground depending on the ratio of the two resistors.
V = (390 / (1000 + 390 )) x 5 = 1.40V
The gear voltages at the CPU pin, 1st to 6th are:
1.40
2.00
2.62
3.08
3.40
4.25
As you can see the ECU was designed to work with all but one of the gear lines disconnected.
BTW the neutral signal is a seperate digital input signal. I noticed in the ECU software that it Neutral is the fail safe condition. The bike is considered in Neutral if the Neutral line is pulled to ground OR no valid gear is selected.
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