what trigger wheel?

[Blue 12]

the following picture shows 2 oem options for a Kawasaki ZX-12R crank trigger wheel (VR). the 8 tooth wheel is for the 2000-03 with a 16 bit ecu and the 04-05 has a 32 bit ecu. (all yrs use a single tooth cam trigger also VR)


the 8 tooth wheel is obviously easier to get the cam trigger between teeth, but is the higher tooth count a better option to use with a MS3x?

my previous experience with MS was running ms2 with the 8 tooth wheel with a tooth cut off and no cam input (wasted spark batch fire) i still have some missing tooth wheels that i can use if thats a better option. I want to run full sequential with the ms3x.

btw i rev to 13000



also for what its worth, the cam trigger position was moved for 01 and on. im not sure if there was an odd issue, but some engineer or team decided it was a good idea.



Ive never had an issue with the 00 position with several bikes with oem ecus. the crank trigger is on the right side of the motor and cam trigger is on the left side on the exh cam.

[CRSTune]

I'd run the 24-1 tooth wheel. Missing tooth code is different than non-missing tooth. With missing tooth, the cam signal is only used to detect phase and is ignored after full sync. You can also revert to semi-sequential if you have issues with the cam sensor (just like you did cutting off 1 tooth of the 8 tooth wheel). You'll also have finer ignition resolution as well with the 24-1.

[Blue 12]

heres a reference of where the sensor is located. sorry about quality, old pic.

TDC lines up with the split in the engine cases



I dont think i had any issues with this with ms2, but someone told me that i could only have been running about 10 degrees of advance with that no matter what i had programmed, and that i should have cut off a different tooth. any truth to that?

[dontz125]

No. The MS2 tracks the crank position pretty much every tooth. Once you have the #1 tooth angle determined and entered, you can run 180deg advance. (Won't accomplish much, but you CAN run that much advance! )

[Blue 12]

I found this in the manual, wondering what they consider high rpm???

A note about VR sensors and missing tooth wheels If using a variable reluctor type sensor with a high tooth count (usually 24 or more teeth), missing tooth wheel, you may experience a loss of sync at high RPM. If this happens, the first thing to try is to put a 10K resistor in parallel with the VR sensor; this can often improve operation with this particular input.

also wondering if this is still an issue with the jb performance vr conditioner board?

i can easily run the 8-1 wheel if it is a better option for 13000 rpm (factory rev limit was 11600)

[dontz125]

The MegaSquirt was based on a V8 car engine, so high RPM is anything much past what we'd consider idle ...

As the frequency of pulses increases, the coil charge in the VR sensor 'pumps up', and may not drop down to the detection threshold before the next tooth arrives. Using a series resistor and/or a shunt resistor helps limit or dissipate the induced magnetic field.


Edit: The jbperf Dual VR board does NOT have shunt resistors installed. Sorry, Jean.

[grom_e30]

i run a gsxr with a 24-2 wheel on the crank up to 14,000rpm on my microsquirt i did have to use the shunt resistor as i had signal problems about 11k and this uses pretty much the same vr conditioner as the dual vr board

[racingmini_mtl]

Th jbperf Dual VR board has shunt resistors installed, with solder jumper pads to select them into the circuits.

No it doesn't. You have to add the shunt resistor if you need one.

Jean

[Blue 12]

So when they say Parallel with the sensor, they are meaning join VR+ to VR- with the resistor correct? (not parallel with the vr+ wire)

[grom_e30]

yeah for the max based vr conditioners (ms3 pro, microsquirt, dual vr board) the resistor goes between the vr + and vr - wires

[Blue 12]

So Ive had several dyno pulls and several combinations of added resistors, parallel and inline and no matter what i do, I loose sync at about 11500 rpm. reason 2. rpm drops right to zero in the log. everything else is good.

wondering if the missing tooth on my wheel is "missing enough"? maybe its hard to read at high rpm and cutting a little bit out would help define the edges???



edited to remove pic of something that was not used

[SwedCharger-67]

I'm slowly starting to open the throttle more and started experiencing a sync loss at higher rpms when testing the burnout capabilities (rpms don't say much... ...old style V8 with 36-1 wheel and VR-sensor and Hall cam sync).
- Tried decreasing the VR air gap to the tooth wheel...seems to make it worse
- Now increased the VR gap significantly, engine starts normally, but not tested the burnouts yet.
- No resistor so far loading the VR sensor.

Maybe it's easily tested to make the gap slightly bigger?

[grom_e30]

my gsxr 24-2 is almost identical to to you 04-5 wheel with the gap being filled in and that was fine at 14,500rpm, maybe post the tune file and some logs to go with

[Blue 12]

i decided to just test the theory of "less teeth will make the problem go away" and so far so good. i turned my 24-1 into a 12-1 and i went to 12800 without issue. thats just about as high as i want to push this engine(turbo pistons are heavy), so i wont be doing anymore tests with a 24-1 in the near future.

[billr]

Have you tried the 24-tooth wheel with the "filled" tooth that is followed by a deep gap? That is the config that makes sense to me, from my experiments using a scope. It is the transition from "no-target" to "target" that gets flaky, signal amplitude varies there.

[Blue 12]

all of my tests with the 24-1 wheel were like you see it in the pic in oem configuration, no modifications. (the wheel beside the 8 tooth wheel in the pics). every test had sync loss at 11500. i have no idea why adding some resistance didnt raise the rpm that the sync loss occurred at, as i thought it was due to increasing voltage, the modified 24-1 wheel ( i cut every other tooth off ) became a 12-1 wheel, and it revved higher without sync loss. it was running fine at idle after the dyno pull. i shut it off, cleared the log and was about to call it a day. wanted to hear it run again, it would not restart. i finally found what i thought was a problem with a bad crimp on the vr wire. i had connected some shielded motec wire to an oem plug. wiggling this connection would blip rpm on the laptop with the bike not running. i replaced this wiring today. i ran oem wires from the plug to the db37 and simply slid a sheath of shielding over top, grounding it at the ms. the bike seemed happy, fired up and i was going to do a dyno run, it shut off and has presented the same problem of not picking up the rpm signal during cranking. i swapped the sensor with no change, bypassed the vr board and absolutely nothing gets picked up, no blips or any signs of life from the vr sensor. reconnected jb board, just a few blips of rpm here and there, nothing that is enough to get the bike running.

[billr]

Ha, I'm confused and going in circles. I thought you cut half the teeth off a 24-1 (as shown in picture) and ran it as a 12-something for most recent try. Also, it seems you deleted the picture of the "deep tooth" 24-1 wheel, the one I was discussing and think would work best...

PS: Why not use an AC voltmeter to get a clue as to what the VR amplitude is when revved up?

[Blue 12]

the picture i deleted was a trigger wheel for a zx14. it is not directly compatible with my zx12r, i was just talking about how its missing tooth area was deeper than the zx12r missing tooth area. to clear things up 2000-03 zx12r used an 8 tooth (non missing) trigger wheel. 2004-05 used a newer faster ecu and had the 24-1 wheel in the pics still in this thread. its a direct swap onto my 2000 zx12r crankshaft. i was using this wheel as i wanted to run missing tooth code. the problem was i had sync loss at 11500. i then was wondering if the reason could be that the missing tooth area wasnt very deep, and may be confused for a tooth at high rpm. the zx12r was discontinued in 2006 and replaced by the zx14, which has the 24-1 wheel with the larger cutout for its missing tooth area. possibly a better design??? more engineering into it? not sure. next dyno tests were with the 24-1 wheel turned into a 12-1 wheel. 2 runs without sync loss above 11500. i thought it was fixed. now it doesnt want to run

19449492_10158766179395004_301931628_o.jpg

[Blue 12]

when cranking the motor over with the starter im getting 2.2-2.3vac

[billr]

What wheel was your sensor originally for, the 8-tooth or the 24-1 with "filled" gap? I would use the (unmodified) 24-1 with the exact sensor it had OEM, and would use the mainboard CKP input.

I take it you don't want to discuss why I feel the zx14 wheel is a better choice, correct?