Thread: Tacho feed and other gauges on 4BD1 Defender

The 4BD1T is so reliable you don't need to monitor anything

But seriously.
#1 is EGT. This is by far the most important for a turbo. I run an Auber Instruments EGT which is excellent.
I also have a VDO 2" boost guage and a VDO Temp guage and sender (to replace the crap OEM one).
All the rest are stock.

I originally wanted to fit a tacho, however There really is no point. The rev range is narrow enough and the engine loud enough that it isn't needed .

The idiot light for oil pressure is set fairly high, so I haven't found the need for a guage.

In the future If I were to fit anything else it would be:
Low coolant alarm
T-case and gearbox temp
Oil Temp

If I was building a new vehicle I would look carefully at the Madman EMS setup.

Originally Posted by Lotz-A-Landies

Q 1. Does the standard alternator on the 4BD1 have an impulse terminal that could be used for a tacho feed like on the V8s and TD5 alternators and what is the relationship between the alternator speed and the crank speed?

On the 4BD1T's the alternator does. I presume they are all close for pulses/rev at idle. If not you can buy a VDO 2" tacho which has calibration or buy a Dakota Digital tacho converter to allow you to calibrate it. I've just bought one of these for my work car, about $US110 incl postage to NZ.

Additional gauges, boost and EGT if you tweak it in any way (why wouldn't you?).

Any alternator can be modified for tacho output. It's simply one wire soldered to a diode/stator junction. Accuracy not guaranteed unless your pulley ratios match the OEM or you have a converter as Dougal says.

Originally Posted by bee utey

Any alternator can be modified for tacho output. It's simply one wire soldered to a diode/stator junction. Accuracy not guaranteed unless your pulley ratios match the OEM or you have a converter as Dougal says.

Yes, I need to do this on my work car. Anyone here done it?

I used to like VDO gauges, but lately I am finding that the plastic housing cracks away from the face, even though it is protected from the UV.

Only an issue if you have a habit of keeping cars for several decades (which I do).

Originally Posted by Lotz-A-Landies

I used to like VDO gauges, but lately I am finding that the plastic housing cracks away from the face, even though it is protected from the UV.

Only an issue if you have a hbit of keeping cars for several decades (which I do).

That happened to my temp guage recently. JohnR on here owns Lionel otto instruments, who fixed it for me at a reasonable price.

Fit a madman ems, don't worry about a tacho, it has an engine speed governor

Originally Posted by Dougal

Yes, I need to do this on my work car. Anyone here done it?

Only on Bosch alternators as these are all I normally fit to Land Rovers by choice. The principle is exactly the same with other alternators though, you need access to the stator-to-diode soldered junctions, fit a new wire tag and extend outside.