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Common / ConnectingRPMSensors

Connecting the RPM pickup

* If you connect a "high level" signal to the "low level" RPM input, you will damage the DL1
* Never connect anything directly to the high tension / high voltage output of the coil, this will almost certainly destroy the DL1

In this section you can learn how to connect an RPM to the Data Logging Units. Information will also be given on connecting the RPM to your vehicle. Please check the RPM connections carefully. Due the power output of the ignition system, it is possible to damage the data logger unit if it is connected incorrectly. Damage caused by incorrect installation is not covered by the product guarantee.


For more information on the DL1 connectors for different models here:

DL1 MK1 and MK2 - DL1 SPORT - DL1 MK3 and CLUB - DL1 PRO and DL1 WP

The DL1 can be used with either a "high level" input or a "low level" input for maximum flexibility. In both cases, the maximum frequency is in excess of 1kHz so even if you are detecting on the king lead of a V8 with a distributor then the maximum is >12000rpm.

If you are detecting the RPM using the high level pickup, then it should be connected to the DL1 on its "RPM High Level (rH)/Spark In" and "RPM High Level Ground (rG)/Spark Gnd" inputs. Alternately, the DL1 can detect RPM from a low level source by connecting to the "RPM Low Level (rL)/RPM [5v]" input. This is suitable for connecting to RPM outputs from an ECU or Tacho signal. This input requires a minimum input of 5v to trigger it, but it is protected up to the battery voltage (15v).

Because the number of different ways that you can connect the DL1 to RPM sources, there are no "standard" leads shipped with our products - if you require a particular lead for you application, then please contact

Please be aware that it’s simply impossible for Race Technology to answer questions like:

  • has my ECU got an RPM output, and is it suitable
  • which wire should I use on my coil pack or sensor

We just don’t have access to that type of information. If you are unsure then the Internet - particularly car user forums - is a great resource that we would refer you to use.


For more information on the DASH2 connections, click here.

The DASH2 can be used to connect to “Low Level” RPM inputs. This is suitable for connecting to outputs from and ECU, Tacho signal or hall effect sensor. Connections are to “Engine Speed Input” and a ground connection. If you require a high level input we recommend using a DL1 data logger which can then transmit the signal to the DASH2.


For more information on the DASH2 PRO connections, click here.

The DASH2 PRO can receive both “high level” and “low level” RPM input signals for maximum flexibility. Please ensure you connect the correct signal type to the correct input connections, as an incorrectly connected high level signal can damage the unit.

Connection methods

Type of RPM pickup connectionInput UsedReliability.
*=Bad, *****=good
Ease of installation.
*=difficult, *****=simple
Guaranteed available
including during over reving etc
Additional notes
Dedicated tacho output from ECU or ignition box (not a feed to a coil pack)low level*********yes 
Clip attached to an HT lead on a distibutor or "remote coil pack" distributorless systemhigh level***noRequires care and maybe experimentation to get a 100% reliable signal
Attached to a coil on a distributor systemhigh level*****no 
Attached to a low power signal on a "remote coil pack" or "coil on plug" systemlow level******no 
Attached to a high power signal on a "remote coil pack" or "coil on plug" systemhigh level*****no 
Connected to the switched side of a fuel injectorlow level*******no 
Using a wheel speed sensor to detect RPM directlylow level******yes 
Output from a flywheel pickuplow level*********yesmust be a hall effect sensor (not an inductive pickup), and only suitable for installations up to about 20 teeth
Output from a camshaft pickuplow level*********yesmust be a hall effect sensor (not an inductive pickup)
Page last modified on June 24, 2015, at 06:29 AM