Speed sensor

ASF72
Posts: 2
Joined: Wed Apr 13, 2011 9:13 pm

Speed sensor

Postby ASF72 » Thu Apr 14, 2011 11:02 am

Hi all,

I have a dash2 with the speed sensor supplied from RT, speedo is accurate up to say 90mph then just goes to zero after that until I slow down again, I'm using one pick up point.

Please help.

Nino

osborni
Posts: 497
Joined: Fri Dec 07, 2007 9:08 pm
Location: USA, Michigan

Postby osborni » Fri Apr 15, 2011 5:12 pm

Check the clearance between the sensor and the bolt head. You may also need to get a bigger target.

Basically what happens is the target passes the sensor faster than the sensor is able to read it. It appears and is gone before the sensor can change states.

I ran into this same issue before. The clearance is critical as is the size of the target.
BMW 2000 M Coupe

ASF72
Posts: 2
Joined: Wed Apr 13, 2011 9:13 pm

Postby ASF72 » Sun Apr 17, 2011 12:15 am

Thank you for the reply,

Any ideas on sizes of the target area and for gapping?????.

Rob Stevens
Posts: 36
Joined: Sun Oct 31, 2010 9:36 am

Postby Rob Stevens » Mon Apr 18, 2011 7:51 am

50/50 gap to steel and around 6 to 8 targets per revolution works for me

osborni
Posts: 497
Joined: Fri Dec 07, 2007 9:08 pm
Location: USA, Michigan

Postby osborni » Mon Apr 18, 2011 3:44 pm

What rob said.

The bolt head I have is about 1/2" long and the air gap is about 1mm.

I did some math that suggests a target of about 1" would allow a greater than 130-140 mph speed before the sensor misses the target. That't on a 120mm (~4.7") wheel bearing flange diameter.
BMW 2000 M Coupe


Return to “Sensor-related questions”

Who is online

Users browsing this forum: No registered users and 41 guests