wheel speed sensor trigger wheel

milt · Joined: 26 Dec 2009 Posts: 4 Location: Virginia

We have a DL2 with DASH2 and using the hall effect wheel speed sensors from Race Techology. Having some difficulty with finding an adequate trigger wheel for our application (Porsche 914). Probably will need a sprocket style wheel fabricated. Hoping someone could make recommendations on what would be optimal as far as tooth height, tooth spacing and target thickness. I saw the diagram on the knowledge base and could not figure out these particular parameters. Our max speed should be aroung 158 revolutions/minute, based on a tire diameter of 23 inches and vehicular speed of 130 MPH.

Thanks,

Milt McPherson

osborni · Joined: 07 Dec 2007 Posts: 234

One bolt head per rev should be enough. No need for a tooth wheel. I use that and it has enough resolution above ~45 mph or so to pick up ABS applications.
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BMW 2000 MCoupe

milt · Joined: 26 Dec 2009 Posts: 4 Location: Virginia

Thanks osborni. We don't have ABS and really looking for wheel lock up during braking or differentials between wheels on the same axle to determine if we are having loss of traction (track car). We basically got the wheel speed sensors and have not felt we had a handle on all the other data to use them but since it's winter and we are trying to get ready for the spring races, I thought we would try to get everything right.

Milt

milt · Joined: 26 Dec 2009 Posts: 4 Location: Virginia

O.k. not much help yet so I'll try this. Looks like I can use the air vents on the front rotors for the front wheels and I can use the bolt heads for the CV joints on the gearbox for the rear. The front will have like 100 tooth spacings/revolution and the rear will only have 6 spacings/revolution. Can the DL2 be set up to adjust for the difference?

Thanks,
Milt

osborni · Joined: 07 Dec 2007 Posts: 234

You can do some math with a user defined function to scale them.

You might want to check the sampling rate capability for the frequencies. IIRC, they are about 100hz. So a 100 per rev might be too much....
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BMW 2000 MCoupe

milt · Joined: 26 Dec 2009 Posts: 4 Location: Virginia

Thanks again osborni. I'll go ahead and mount the sensors and then see if my son can adjust the DL2 for the frequencies. At least now I know we can sample different frequencies. I'll also investigate the front rotors to see if another lower frequency opportuniy exists.

Milt

osborni · Joined: 07 Dec 2007 Posts: 234

I mount my front speed sensors through the brake duct backing plate and pick up a bolt head on the back side of the wheel bearing flange.
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BMW 2000 MCoupe