Moderators: jsmcortina, muythaibxr
I've started too many threads with the key words cutting out with no resolve.billr wrote:I gotta say... the 36-1 wheel is one of the easiest to get right. If you have problems with that, then 129+1 might be even worse. How about starting a fresh thread, with your MSQ/MSL and short description of the problems. A tooth-log, too, if your MSL shows a lot of sync-loss.
Not quite, I would be using the OEM trigger, which should be free of noise susceptibility being designed by an EE.elaw wrote:I completely agree. At the most basic level, if you're having noise problems with one trigger wheel and sensor, it's pretty unlikely the situation will improve with two wheels and sensors!
The only way I can see things improving is if the location of the 36-1 wheel (presumably on the damper) forces you to put the sensor or wiring in an electrically noisy location and the tri-tach turns out to be better because it's location (presumably on the flywheel) is different. But that's a big gamble... a much better bet would be to determine the source of the noise and deal with it appropriately.
Well, as you might know, my VR is running within a few inches from the alternator. The alternator is behind the cooling fan for air-cooled 911's. I cannot physically move the VR away from there since the alternator and crank are so close together.prof315 wrote:The factory triggering may have been designed by an EE but here's the catch....So was the conditioning circuitry in the factory ECU and they were designed to work together. You aren't using a factory ECU with that exact circuit, you are using a generic conditioner.
That might be your explanation right there... alternators (and their wiring) can emit pretty powerful magnetic fields. Have you ever tried a Hall sensor instead of the VR? They can be less sensitive to external interference.Tippy wrote:Well, as you might know, my VR is running within a few inches from the alternator. The alternator is behind the cooling fan for air-cooled 911's. I cannot physically move the VR away from there since the alternator and crank are so close together.
That's too bad because from a triggering perspective, it would be a great option. Is there any chance of getting a reasonably-priced used one and having it lightened?Tippy wrote:My only for sure option is to change out the FW to the uber expensive 90-98, which is very heavy too.
Hall has crossed my mind, but then I'd need magnets on the trigger wheel, no? Or can some read just ferrous metal? Going to Googles now...elaw wrote:That might be your explanation right there... alternators (and their wiring) can emit pretty powerful magnetic fields. Have you ever tried a Hall sensor instead of the VR? They can be less sensitive to external interference.Tippy wrote:Well, as you might know, my VR is running within a few inches from the alternator. The alternator is behind the cooling fan for air-cooled 911's. I cannot physically move the VR away from there since the alternator and crank are so close together.
That's too bad because from a triggering perspective, it would be a great option. Is there any chance of getting a reasonably-priced used one and having it lightened?Tippy wrote:My only for sure option is to change out the FW to the uber expensive 90-98, which is very heavy too.
Of course in general swapping a flywheel isn't nearly as easy as swapping a crank sensor...
So the ones from DIY would work with a 60-2 flywheel WITHOUT magnets?elaw wrote:No, a Hall sensor in the most generic sense would require magnets, but they make ones now designed for this exact purpose that don't... actually the sensor has a magnet in it. Wow that was a jumble of words but hopefully you understand!
Either of the two at the top of this list would work fine: https://www.diyautotune.com/?s=hall
...and actually they'd work with the 60-2 flywheel too. I think there are some here that would disagree, but I think Hall sensors are much easier to work with than VR... they're less finicky. The only downside is they require power so if you have an existing cable with only 2 conductors it would need to be replaced with 3-conductor.
Thank you Eric! I have a braided sheath that I am going to try from work first to see if I make a difference first before doing Hall. My EE coworkers use it to block noise with it on ad hoc, quick setups.elaw wrote:Absolulely! Assuming you can get the sensor to fit where it needs to go, of course.
If you're curious, here's a datasheet for a similar sensor: http://www.littelfuse.com/~/media/elect ... et.pdf.pdf
Hey Dennis,Dennis930 wrote:Tippy,
I am running an Electromotive 60-2 wheel and their VR sensor from my old crankfire set up. I have no issues with it. I did have to tweak the R52 and R56 pots on the V3.0 board at first. The wire itself is coaxial and is routed along the left side of the fan shroud and under the intake manifold to the left corner of the engine. The coaxial is carried on to MS3 via a 22 pin Weathershield connector, with the cable provided in the DIY MS3 wiring harness I bought when wiring the system. I also have 6 LS2 (514) coils mounted along the outside of the 3.2 Carrera intake runners for twin plug ignition that could be another source of EMI. Maybe the newer higher amp alternators with the built-in regulator are more noisy in your case.
