Fitting a tacho to a Perentie

[mick88]

Anyone fitted a tacho to their perentie?
If so what type?




Cheers, Mick.

[Mick_Marsh]

Very good question. I'd like to do the same thing.

[Homestar]

There would be 2 options as far as I could see.

Option 1 would be to convert the alternator so it has a 'W' terminal then run a tacho that can see that input - not sure what aftermarket tachos there are that will do this. The pulley ratios would need to be calculated.

Option 2 would be to use an aftermarket gauge (like a Murphy or Datcom unit) that picks up a signal from a mag pickup (speed sensor). Unless you have a hole drilled and tapped into the flywheel housing directly over the flywheel teeth, then this could potentially be a big job as you really need the engine out and the flywheel off to do this. You then just could the teeth on the flywheel and calibrate the unit. Our gensets use this style of sensing, usually into the control panel, but we do have some with gauges too.

Option 1 would be easier if you can find a tacho, option 2 will definitely work, but needs a hole drilled and tapped into the flywheel.

I'm sure there may be other ways - they are the 2 I know of.

EDIT - just having a think about it, a tacho like this - http://www.fwmurphy.com/uploaded/00-02-0260.pdf that is designed to work of a mag pickup may still work off the 'W' terminal, depending on its calibration range, but someone smarter than me would need to work out the pulses per RPM that comes out of the alternator with its pulley ratios.

[Homestar]

Option 3 - cheap and nasty RED LED 4 Digital Tachometer RPM Speed Meter NPN Hall Proximity Switch Sensor | eBay

Find a spot of the front pulley to glue a magnet to and make a bracket up to suit the sensor. It would work, but it would look like crap and be prone to mechanical damage.

EDIT - can anyone see these stupid links from ebay, or is it just me???

[Homestar]

This may be an easy solution - http://www.autometer.com/productPDF/608.pdf

http://www.autometer.com/cat_gaugedetail.aspx?gid=2602

Looks like around $140 USD

[Mick_Marsh]

I'd like a nice looking tacho like that Murphy one. The next question would be where do you put it?

[isuzurover]

I recall isuzu have a genuine tach. There are also aftermarket tachs which attach a sensor to nr.1 injector pipe to measure fuel pulses.

[rovercare]

http://www.aulro.com/afvb/technical-chatter/35192-tachometer-4bd1-2.html

[Bigbjorn]

I bought a genuine Isuzu tacho and sender from Zenith Engineering, the Isuzu industrial engine dealer in Brisbane. The sender replaces any one of the four threaded plugs underneath the injection pump.

[Bearman]

Here's where I mounted mine.The alternator photos can be found in the thread "alternator w connection". The three gauges on the dash top are from left, boost,egt and rpm.

[rovercare]

I'm still not sure why though, you can hold these things on the engine governer all day long without harm, I'd save the bucks and use it on diesel in it:D

[isuzurover]

I'm still not sure why though, you can hold these things on the engine governer all day long without harm, I'd save the bucks and use it on diesel in it:D

Likewise I have never seen the point of fitting one.

[JDNSW]

Likewise I have never seen the point of fitting one.

Likewise - I've thought about it, but then, thinking about the work and money involved, why bother?

For that matter, while they seem to be pretty much obligatory these days for anything with wheels, very few of them provide anything that is at all useful - spending the cost of them on an oil pressure gauge or a decent temperature gauge would seem more useful for most vehicles.

John

[mick88]

There would be 2 options as far as I could see.

Option 1 would be to convert the alternator so it has a 'W' terminal then run a tacho that can see that input - not sure what aftermarket tachos there are that will do this. The pulley ratios would need to be calculated.

Option 2 would be to use an aftermarket gauge (like a Murphy or Datcom unit) that picks up a signal from a mag pickup (speed sensor). Unless you have a hole drilled and tapped into the flywheel housing directly over the flywheel teeth, then this could potentially be a big job as you really need the engine out and the flywheel off to do this. You then just could the teeth on the flywheel and calibrate the unit. Our gensets use this style of sensing, usually into the control panel, but we do have some with gauges too.

Option 1 would be easier if you can find a tacho, option 2 will definitely work, but needs a hole drilled and tapped into the flywheel.





I'm sure there may be other ways - they are the 2 I know of.

EDIT - just having a think about it, a tacho like this - http://www.fwmurphy.com/uploaded/00-02-0260.pdf that is designed to work of a mag pickup may still work off the 'W' terminal, depending on its calibration range, but someone smarter than me would need to work out the pulses per RPM that comes out of the alternator with its pulley ratios.


Gav,
my vehicle is an FFR and has an hour meter fitted!
So....would it already have the required sender that could be utilised for a tacho?


Cheers, Mick.

[mick88]

I bought a genuine Isuzu tacho and sender from Zenith Engineering, the Isuzu industrial engine dealer in Brisbane. The sender replaces any one of the four threaded plugs underneath the injection pump.



Brian,
may I ask what the damage was?
(answer in dollars or litres will suffice ;) )


Thankyou!
Cheers, Mick.

[Aaron IIA]

Does your hour meter count operating hours or crankshaft rotations?
Aaron

[isuzurover]

Brian,
may I ask what the damage was?
(answer in dollars or litres will suffice ;) )


Thankyou!
Cheers, Mick.

Did you read the link rovercare posted?

[Mick_Marsh]

When I went for my HR license, the instructor had me changing gear based on the RPM of the motor as read from the tacho. I just think that would more suit my driving style rather than changing gears when it hits the rev limiter. It would probably make changing down easier when practicing double de-clutching.

[rovercare]

When I went for my HR license, the instructor had me changing gear based on the RPM of the motor as read from the tacho. I just think that would more suit my driving style rather than changing gears when it hits the rev limiter. It would probably make changing down easier when practicing double de-clutching.

Its called feel, I drove a 4BD1 LT95 in a rangie with no clutch for a few weeks, I was working bulk hours and it was the only moving vehicle at the time....no tacho

Just crank it in first low to get started, up through to 4th, shift on the fly to high range 3rd and into 4th

You certainly should not need a tacho

[Vern]

You can't shift from low to high on the fly, surely you know that:p

[Mick_Marsh]

You certainly should not need a tacho
Well, don't need but nice to have whilst practicing.
I don't have a tacho on the hybrid and the poor old LT95 is getting a thrashing.
That's why I need to practice.

[rovercare]

Well, don't need but nice to have whilst practicing.
I don't have a tacho on the hybrid and the poor old LT95 is getting a thrashing.
That's why I need to practice.

You have trouble changing gears on feel?:confused:

LT95's are full of feedback:)

If you feel you need something to work with, just use the speedo, the speed in each gear does not change, just like a tacho, its a fixed given, just ratio's

[Mick_Marsh]

You have trouble changing gears on feel?:confused:
Not on the Commodore.


LT95's are full of feedback:)
As long as it doesn't become full of broken teeth.


If you feel you need something to work with, just use the speedo, the speed in each gear does not change, just like a tacho, its a fixed given, just ratio's
I do that in the hybrid but I am finding it difficult to judge in the Perentie. It's all different. Different motor. Different gearing. Different sound.
I think a tacho will help. It's how I learnt in the truck.

[rovercare]

Not on the Commodore.


As long as it doesn't become full of broken teeth.


I do that in the hybrid but I am finding it difficult to judge in the Perentie. It's all different. Different motor. Different gearing. Different sound.
I think a tacho will help. It's how I learnt in the truck.

Just use speedo then, same info as tacho really, pick speeds for gear changes, although its soemthing that varies with road/wind conditions, so I still say feel:D

Good luck breaking teeth in an LT95

[DBT]

In a 4BD1 Perentie, on flat road:

1st gear to 20kph
2nd to 40kph
3rd to 60kph (-ish)

Hold a little longer when going up hill. Or a lot longer, if going uphill and you need to keep up with traffic. :(

Yours may differ slightly, but this will keep you from bashing the governor limit. And as a bonus your ears won't bleed too much either.

[JDNSW]

You can't shift from low to high on the fly, surely you know that:p
Speak for yourself!

John

[Aaron IIA]

You can't shift from low to high on the fly, surely you know that:p

I certainly can. I drove around for about a month without a working clutch. Start the engine in first low, change to high ratio, then work up the gears. To slow down, work down the gears to first, then change to low ratio. No tachometer necessary. Listen to the engine.
Aaron

[Mick_Marsh]

Listen to the engine.
Yep. That's what the instructor said how I'll be doing it as I gain experience, in the mean time, use the tacho.
I'm not sure whether you lot realise this but a 4cyl turbo diesel sounds different to a v8 petrol.

[Aaron IIA]

I have both a four cylinder diesel and V8 petrol. Can change gears in both of them with or without the clutch. It comes down to learning the sounds of the engine and the ratios of the gearbox.
Aaron

[Mick_Marsh]

It comes down to learning the sounds of the engine and the ratios of the gearbox.
Yep. That's what the instructor said and, in the mean time, use the tacho.

[DBT]

The biggest issue I have when jumping between vehicles is remembering not to flick the wipers on when turning. :censored:

Gear changes, not so much. Even switching between a 4 speed and 6 speed manual. Once you know the car, you rarely look at the tachometer, if fitted.

Drive only the Perentie for a week. That'll learn ya. :D

[isuzurover]

Just use speedo then, same info as tacho really, pick speeds for gear changes, ...

Exactly. When my clutch hydraulics failed I just worked out what speeds to change gears. Drove over 300 km like that...

[rovercare]

Yep. That's what the instructor said how I'll be doing it as I gain experience, in the mean time, use the tacho.
I'm not sure whether you lot realise this but a 4cyl turbo diesel sounds different to a v8 petrol.

Think I've had 3 4BD1's and dozens of V8 petrols with LT95's

Whats with the mental block that says you need a tacho? speedo, same deal:p

[mick88]

What ratio diffs do the Perenties have?


Cheers, Mick.

[BadCo.]

Google tells me 3.54 on the 4x4 and 4.7 on the 6x6.

What's the relevance of the question in this old thread?

[Outback]

Directly related to RPMs of the engine.

[Mick_Marsh]

Directly related to RPMs of the engine.
Odd, that. The faster the engine spins, the faster the wheel spins.

There was a thread elsewhere that mentioned diff ratios. It also referred to transfer case ratios.

I thought this thread was very interesting. It's full of diff ratios, transfer case ratios and gear box ratios.
http://www.aulro.com/afvb/military-land-rovers/208105-ex-army-110-gearbox-different-defender.html