The Logical Device to Fit - if you have an Overdrive

Logic overdrive devices.

I have read with some amusement all the too-ings and fro-ings on this subject with some correspondents making it all sound desperately difficult.

What is the background? Well, when Revington TR was called TR Spares Southwest in 1982 ish, I designed a device to allow me to change gear and overdrive at the same time specifically with racing in mind but obviously I found that the device was a fantastic improvement on all cars both road and competition. I called this device a ’Logic Overdrive device’ (sound familiar?)

Initially the device was constructed of basic electrics but has since been redesigned and is now fully electronic.

RTR1001K

RTR1296NK

RTR8436

So how does it operate and how do you fit it? There is no need to remove the gearbox tunnel, the box of tricks and all the other fittings that come in the kit (which comes with full instructions), is wired into the existing wiring from the gearbox tunnel upwards to the switch and original relay (pre CF CR TR6 cars). A flick switch RTR8436 is used to operate the system and in the case of TR4-6 the original switch can be modified to become a flick switch (Meaning momentary operation with self-return). The modus operandi is this: Whatever gear or state of overdrive the car is in when the ignition is turned off, the overdrive will be off when you turn on the ignition again. When overdrive is required (in an overdrive enabled gear of course), flick the switch. When a non-overdrive gear is required from an overdrive gear, flick the switch. If a fast change is required from say 2^nd overdrive to non -overdrive 3^rd , just move the gear lever to 3^rd and the logic device will disengage overdrive for you as you pass through the gear shift gate. This applies to any gear change up or down the gearbox where the start point was an overdrive gear.

We recommend a light on the dash to identify the overdrive state.  And it is worth noting that both negative and positive earth devices are available.

Two types of kits are available RTR1001K which is a basic unit suitable for both positive and negative earth and RTR1296NK, RTR1296PK which provide a facility to dim the indicator lamp independently for both day and night. The ‘N’ and the ‘P’ in these part numbers indicates negative and positive earth variants.

To find out prices and more, just click on the part numbers above or type these part numbers into the search box on our website www.revingtontr.com 

That is the history and I can confirm these units have been sold by their thousands and continue to work faultlessly in many applications (not just TR’s) around the world, so now there is no need to go searching for components to build a device that may or may not work, it has all be designed for you and been field tested in thousands of cars for the last 30 years.

J. Neil Revington