trip computers ?

[grainger]

hi

anyone have any thoughts about getting a trip computer like david vizzard mentions in his a series book, i bet it would be a great way to drive more economically. any idea where you can get something like this ?

cheers
grainger

[Matt]

You could use a push bike speedo prehaps?

[Cam]

Just get a vacuum gauge and drive in the 'green' segment:

[Peetee]

Just get a vacuum gauge and drive in the 'green' segment

Pah. You're not catching me driving everywhere at 15mph.

[Relfy]

um... whats a trip computer?

[Pyoor_Kate]

'tis a device which calculates such things as MPG, Total travelled in a trip, average speed [last X mile], average speed over the trip, and other similar things.

The Yaris I rented in Ireland had one, and I had great pleasure in watching it go spare every time we stopped (35mpg....31mpg...20mpg....10mpg....0mpg. Accurate, but useless! )

As to whether they're any use, I dunno, I just considered it an odd toy; and quite depressing (the average speed always remained staggeringly low).

[Kevin]

um... whats a trip computer?

Its a floor mounted PC that you can trip over (sorry couldn`t resist it)

[Stig]

hi

anyone have any thoughts about getting a trip computer like david vizzard mentions in his a series book, i bet it would be a great way to drive more economically. any idea where you can get something like this ?

cheers
grainger

They did fit them in some of the posher A-series Metro's so if you're lucky enough to find one in a breakers...
Never actually seen one, but it's mentioned in the Haynes manual.

[grainger]

really ? thats definately worth looking out for. thanks

cam, i might just do that, (would my brake servo affect it ?) but i would really prefer a more measured reading, so i can see im doing 40 mpg or whatever while im doodling round peacefully ... until some nob cuts me up and i drop gears and go chasing up his behind, i could see the consumption rising and i would say to myself ... " is it really worth it ? ... course its not ! " .. ...

cheers
grainger

[Cam]

(would my brake servo affect it ?)

Nope! Not at all.

while im doodling round peacefully ... until some nob cuts me up and i drop gears and go chasing up his behind, i could see the consumption rising and i would say to myself ... " is it really worth it ? ... course its not ! "

Well, you can get that with the gauge.

but i would really prefer a more measured reading, so i can see im doing 40 mpg or whatever

Bit expensive though and I think they work off a few sensors such as the Lambda sensor on modern cars....... So it might prove difficult to easily get one to work with a Moggy.

My mate's BMW M3 had one on the computer next to the gearstick and when he floored it it used to drop down to about 7MPG!!!

Might be worth checking out such places like Demon Tweeks or the such like. If they do Mini ones, then I'm sure they could perhaps be adapted for Moggies!

[Kevin]

Bit expensive though and I think they work off a few sensors such as the Lambda sensor on modern cars....... So it might prove difficult to easily get one to work with a Moggy.

Id go with a Vacuume guage they are only about £15 - £20.

[lowedb]

The old mxxxo hle's had 'economy' guages which were just a vacuum guage by another name. Basically the less you open the throttle, the more vacuum and the more economically you are driving. Cheap and simple, which is why they did this.

Proper trip computers actually measure fuel used, and speed / distance. Older cars with carbs used to have a flow meter for the fuel, and a pickup in the speedo cable. These days the engine management computer knows how much fuel it's injecting, and the ABS knows speed / distance, and the 'trip computer' (now usually just a bit of software inside the instrument pack) calculates the various info.

So, you could probably get a trip computer but there's a fair bit of work fitting one to a mog and calibrating it. I'd go with the vac guage as well!

[rayofleamington]

I had great pleasure in watching it go spare every time we stopped (35mpg....31mpg...20mpg....10mpg....0mpg

Ah yes but that's old hat - my late 80's Volvo could do all that. The modern equivalent tells you how many litres of fuel per hour you are burning when you are stationary, and will also tell you that you are doing a zillion miles per gallon when engine braking (as they cut off the fuel).

[Kevin]

and will also tell you that you are doing a zillion miles per gallon when engine braking

So not much use in a Moggie then....................

[rayofleamington]

So not much use in a Moggie then....................

nah - because even if you installed a cut off switch for the fuel pump it would still run the engine for another 30 seconds anyway

[JustinMinor1000]

So, you could probably get a trip computer but there's a fair bit of work fitting one to a mog and calibrating it. I'd go with the vac guage as well!

The mog is pretty well placed for a home brew trip computer or just a MPG display. There is no need to fit a sensor to the fuel lne as you can simply count the times the fuel pump pumps. Then if you look at the low tension people they cab supply a "Universal" speedo impulser. Program a basic stamp with an LCD display and bobs your Aunties live in Lover. Calibration is comparitively simple just a one litre graduated jar on the fuel line to the carb (pic counts the pulses) and either calculated or number of pulses in 10 miles say. Also you could make the output average over ten minetes so no spurious figures.

It would be interesting to build the hardware if only because you could do lot's of other funcky stuff with it such as water temp display and even better intelegent fan (assuming you fit ann electric fan of course.

[Cam]

Counting the clicks from the fuel pump is not really a reliable measure of the fuel used, as temperature and pressure make it a bit non-linear.

And I think programming a PIC (although dead easy to some) is probably a bit too awkward for general Moggy owners!! Buying a gauge is far simpler!

You COULD build a fairly complex trip computer incorporating loads (I considered it years ago for my Mini based on a 6502 MPU) but apart from it being an interesting thing to do, it's expensive and not that practical.

[grainger]

ps ... i only have one outlet from my manifold, can you fit a junction pipe for a vacuum gauge maybe ... ?

the idea of homebrewing a bit of electronics isnt totally beyond me (maybe you could do the maths for mpg, average speed etc. with analog computers, rather than digitally, somehow, using op(erational) amps, as simple integrators ?)

cheers
grainger

[Cam]

can you fit a junction pipe for a vacuum gauge maybe ... ?

Yep, no problem. You can usually find them in scrapyards on Metros or other BL offerings.

(maybe you could do the maths for mpg, average speed etc. with analog computers, rather than digitally, somehow, using op(erational) amps, as simple integrators ?)

VERY possible and quite easy too! Just create a F/V converter using an op-amp and drive a uA meter. That's basically how rev counters work anyway! A few more discrete devices and you are away!

I'm all for analogue, but digital is a bit more stable over a much larger temperature range.......

[Multiphonikks]

'tis a device which calculates such things as MPG, Total travelled in a trip, average speed [last X mile], average speed over the trip, and other similar things.

The Yaris I rented in Ireland had one, and I had great pleasure in watching it go spare every time we stopped (35mpg....31mpg...20mpg....10mpg....0mpg. Accurate, but useless! )

As to whether they're any use, I dunno, I just considered it an odd toy; and quite depressing (the average speed always remained staggeringly low).

Aye, it's in the radio panel... *mumbles rude words*... Actually, I quite liked the Yaris... But then, when I had one it was only just after I passed my driving test...