Race Technology

Hi,

I've recently installed a dash 2 (nothing else) into my kitcar (not iva'd yet).
I've been having a problem with the wheel speed sensor, it's a bolt type hall effect sensor from demon tweeks.

I've done some maths and as I installed the sensor on the prop shaft I get too many pulses (13952) max is 12000.

I installed 2 tabs so I only get 2 pulses per rotation rather than 4 and entered 6976.

I tested the speedo and it was giving roughly the correct reading but when I got to 25mph it stopped registering any speed at all.

Is there a simple solution to this as I seem to solve 1 problem and create another?

Cheers, Steve

A) Check the bolt head spacing and the size of the bolt head. Closer is better as is bigger.

B) you really only need 1 bolt.

Hello,

If you are using the sensor as an RPM pickup, you must check that you have a big enough "target" to trigger from, most of our RPM inputs need at least a 1mS pulse to trigger from. Given a pulley diameter of "D" (in mm) and a maximum RPM, then the minimum target size (in mm) can be calculated from "RPM x D / 20000".

Alternatively you can use one of our pulse dividers that will convert the signal into a 50% duty cycle.
http://www.race-technology.com/content. ... &cat=30606

Kind regards,
Support (K)

For what it's worth, I have M8 bolts which have a head of about 8-10mm across (from memory) on a 120mm diameter bolt circle. The signal looses it at around 100-110 MPH. Which is around the 1mS limit described in the equation above (Thanks!)

So I need bigger targets.