BBR's 83GT - 552 BBF version 3.0 (at least)

[TheSilverBuick]

Nope. The crank trigger wheel on my Skylark is off an early 90's Ford Escort that used a VR sensor, but the hall sensor works like a champ. So I used the same sensor for the Firebird crank sensor on a DIYautotune steel trigger wheel and the same sensor now on my Skylark's front right brake rotor for a second VSS. Pretty durable sensors over all. The wire color is a bit funny for automotive use, but it's wiring diagram is on the packaging. iirc, black is sensor, green is ground and grey power.

The interesting thing about running two of them on one car is if for some reason the crank sensor gets trashed (by road debris, etc) I can remove the wheel sensor and install it at the crank. The odds of losing both sensors at once is pretty minimal, well unless I'm plowing through a deep sloppy mud puddle anyways. The wheel one is inside the rim shell.

[BBR]

Bill uses an LS1 sensor, which I just found out is also a Hall Effect. Any drawback to running one of them as opposed to the Cherry?

[TheSilverBuick]

Nope, the only thing you'd have to figure out is if it needs a pull up circuit or not. Bill may or may not know that part as the old EMS-pro I believe had a jumper for it and I wouldn't be surprised if the MS3Pro has something similar built in.

[BBR]

10-4. Might as well stay with the Cherry then. I like that it is threaded to easily set the depth.

[TheSilverBuick]

In my experience, the cherry sensor isn't very picky. Everyone has seen my wiring for sure, but I haven't had any issues setting the gap either. Usually when I'm pulling the engine or balancer I'll just loosen or remove the nut on the trigger wheel side of the bracket so the sensor goes in essentially to the same depth every time I re-install it from the back nut. A few times I forgot to tighten it down so the sensor wobbled it's way out the bracket, and eventually would have an intermittent miss that got worse with rpm. Go and look at it and the dang thing is like a 1/4" away or better from the trigger wheel. Engine still running, sort of.

[DanStokes]

Just to display my ignorance: Is the Hall effect sensor WAY different from my optical tach sensor? I'm guessing the answer is "yes" but it would be a good thing to have a tach signal to send to the dyno instrumentation. As it is, we do a calibration of dyno RPM to tach RPM and the dyno software uses that to roughly give engine RPM - I didn't order the RPM-out option on the phototach (that's what I get for going cheap). Anyhow, I was wondering if there's some sort of pulse train or analog output or something that we could steal from the optical pickup.

Dan

[Deaf Bob]

Dan, I'm not that technical saavy electrical wise, but ..I see no reason why you cannot take a wheel like these boys use and make a tach reading gizmo for your Benny... They read driveline rotations, wheel rotations.. So? Why not crank rotations.. But I will let these experts correct me.. I might be farting upwind

[BBR]

I have no idea. I am learning as I go.

Luckily I found my receipt so I was able to return the Ford vr sensor to O'Reilly's.

[TheSilverBuick]

The optical and hall sensors both output square wave (ON or OFF) signals, they just differ in how they get there. Hall sensors use a magnetic switch that opens and closes every time a ferrous tooth passes by. Optical sensors either use a reflectance or pass through pickup sensor and using a calibrated light source it detects when the light it blocked or decreases in brightness to trigger it's signal. Lots of OEM's use optical sensors in distributors, I think because they are not subject to magnetic interference from surrounding metal. Probably slightly less prone to electrical noise too.

Variable Reluctor (VR) sensors work on the electrical pulse wave generated from moving a metal object through a magnetic field. So the sensor is magnetized, and as a ferrous object/tooth comes by it pulls then pushes electron's around and that's what creates the wave and a signal conditioner is needed to process when the wave goes from high to low and say that's the trigger point. Sensor wise, these are electrically very very simplistic and rugged, and if the sensor is in a harsh environment the conditioner can be placed somewhere "safe". Historically these tolerate heat and vibration better than Hall sensors, but I think hall sensor technology has significantly reduced that advantage.

A cheap test light that works great for testing hall sensors is a simple LED, a 1k resistor and a bit of wire. I just soldered the resistor to one of the LED legs and then some length of wire to each leg from there. I've used this to troubleshoot a few wiring things because the low voltage threashold required to light the LED. When I had the junkyard sourced hall sensor for the cam sensor on the Firebird fail, this little thing made it easy to troubleshoot. Just hook it up to the sensor wire, ground the other side, rotated the distributor base and wen the tab was under the sensor it should have lit up but didn't. Same could be done on your crank. Using a breaker bar, turn the engine and it should light up with every tooth. Here it is in action testing my front wheel speed sensing off rotor casting tabs.

[DanStokes]

Thanks Randal. Monarch will retrofit my readout for $100 so I can get a 4-20 ma or 0-X (I forget the units) DCV out but it sounds like if I was Randal I could whip up a little box to steal the pulse from the optical sensor. Mine works on reflectance. Head scratch time - I never claimed to be any good at electronics and we had an electronics shop at EPA so I could call on them when stumped.

Dan

[BBR]

Cherry hall sensor is ordered! Can't wait to dig into this deeper!

[CDMBill]

Not that this helps at this point, but I switched over to the Cherry Hall effect sensor after my crank sensor issues at DW '14 and the LS events I took the car to in 2014. I already was using one for the cam position sensor and for the front and rear wheel speed sensors. Scott and I added the 1K pull up resistor on the Weather Pack connector so in the event I have to replace the sensor it's a simple swap. I'm using the Cherry on both cars now for all four spots. I was having mystery signal drop outs with the parts store replacement LS1 sensors after years of no issues with the original GM part. We swapped to my spare Cherry and the signal loss issue was gone.

Jeff Mc reports that they had some intermittent issues with the plug and pigtail version of the same Cherry sensor so they have stuck with the version shown in your picture with the four conductor wire permanently attached. I already had those on the 598" so I'm sticking with them, but I have the other version with the plug and pigtail on the wheel sensors as I killed one on the road with some kind of debris (road gator I think) getting into where that sensor lived.

I carry spares of each kind, but have yet to use one. The Cherry I use for the cam sensor has been on the car since I switched to the MS3X back in 2011 with no issues.

[TheSilverBuick]

I too have the 1k resistor up in the harness so if I had to swap the sensor I wouldn't even be messing with the resistor. The sensor pictured, and I use, has 3 wires, not four. I'm assuming it's a brain fart on the wire count.

[BBR]

Good to know! Thanks!

[BBR]

Boom. Speedy delivery! Now I need to figure out a mount!