Using a Hall sensor for Crankshaft Position Sensor

With speeduino, there are some things that these ECUs do no do well with. Noisy sensors being the biggest depending on signal conditioners being used. But in my experience, the EMI susceptibility alone is a reason not go that route with a speeduino, especially with any high revs. Since the voltage magnitude changes depending on how fast the magnetic field changes, you start compounding the possibility of this happening.

Back to hall sensors. Ive had good luck with the Cherry and Honeywell hall sensors on pretty high revving engines.

The tabbed version sold by DIYAutotune is my recommendation and I believe it requires very little modification to fit the stock location. The alternative, would be to go to a DSM CAS. They're easy to diagnose, easy to set up, and surprisingly durable.

The VR issue really only comes up when using a 60 tooth wheel, but that's not too hard to get around with a simple 5k ohm resistor.

But yeah, Hall sensors are great when kept cool. I think the GT101 sensor is decent in that regard.

culberro said:

The VR issue really only comes up when using a 60 tooth wheel, but that's not too hard to get around with a simple 5k ohm resistor.

But yeah, Hall sensors are great when kept cool. I think the GT101 sensor is decent in that regard.

Click to expand...

The few speeduino's that I've played with seemed to have trouble, and give me headaches with VR sensors, and you're probably on to something with tooth count being the big player as well as revs. The last one I played with was set up an old formula 1000 gsxr based engine, and above 8k it was all over the place with lots of weirdness from both cam and crank signals, and it could have really been any number of things. We decided to change the original VR sensors to hall sensors for both cam and crank, and the problem was solved. I did try the resistor method, but it didnt seem to be an end all solution and wasnt all that stable above the 7k mark.

740atl said:

Klracing sells a crank pulley with a trigger wheel mount. https://shop.klracing.se/sv/artiklar/multiremhjul-vevaxel-16v.html

I know this isn’t for a hall sensor but if you don’t have the room in back, why not in front?

Or why not go with a yoshifab cas setup?

https://yoshifab.com/store/billet-redblock-dsm-cas-adapter.html

Click to expand...

Slight hijack, any disadvantage of the CAS setup over the flywheel triggering besides a few more moving parts?

From Yoshifab site: It also is much more stable than a crank trigger setup in Mega Squirt.

How and why?

Mueller said:

Slight hijack, any disadvantage of the CAS setup over the flywheel triggering besides a few more moving parts?

Click to expand...

They're just susceptible to alignment issues if you remove them or twist them, just like an oldschool distributor.

I like crank trigger and wasted spark because it's dirt simple and much less likely to screw up when doing t-belts or hectic service work (like on a race car).

When I talked with Josh about the crank trigger "issues", he was having problems with actual spark timing being unstable and not being able to rev high. He was attributing it to crank flex. I don't buy it.

The few crank trigger setups I've done (using the stock VR sensor) all rev over 8k rpm with the rally cars. No issues with crank flex or high revs on those. Super stable spark as well
The instability is pretty well documented when using MS, and it's REALLY easy to fix so it's not an issue.

IMHO it allows instant sequential ignition without the need for a second trigger... for example using the 60-1 crank and a single tooth wheel on the distributor (stock 240 dizzy with all but one tooth cut off) which works well, it's just that getting a dizzy in and out of underneath a 16v head becomes troublesome.

The sequential ignition also allows megasquirt (at least MS3x) to identify which cylinder is knocking as opposed to giving a general 'hey bud you're engine is knocking' warning.

The other day I was doing a crank sensor on an E90 BMW (a 328xi, to be exact), and I thought "I wonder if that would fit a Redblock crank sensor bracket"
It does, with a couple regular M6 washers under the bolt hole, and ends up an acceptable distance from the flywheel. The sensor is at an angle to the mounting position (about 45 degrees) so I tested it to see if I still get a nice square wave with it mounted at an angle (which it would be in a redblock or whiteblock compared to its original application). It does. BMW sells an adapter harness that adapts the weird little connector on the sensor to a D shaped AMP connector common on German cars, and THAT connector uses regular JPT terminals. You can de-pin it and put the pins in a 3 pin male JPT housing which will plug in to the Volvo CAS harness connector. Obviously you need to then make sure the ECU side is set up properly to give +5v to +12 to the sensor, use the shield as sensor ground.

Here are pics of the testing. Anything more than about a 70 degree angle to the direction of rotation and it stops outputting nicely, but that won't be a problem.

Which sensor is used in the Volvo ABS on the front wheels? How accurate is it?

244tiCanuck, great work!