My Evodash needs a speed sensor mounted somewhere. After discovering that my Duratec has one on the gearbox, I decided that it might be better mounted on the front wheel - no wheelspin to mess up the readings for 0-60 times, datalogging etc.

I would interested to see how people have mounted theirs. I was thinking about drilling the Cortina upright to accept the sensor (which is M10 I think) and using the hub bolts as the 'trigger'.

Any other ideas?

[Edited on 7-2-06 by RazMan]

I put mine on the prop shaft...well the magnets anyway!!

You don't want to have it mounted on a wheel, as said above the propshaft is a much better place for it. Think about it this way: -

If you're going round a right-hand corner at 50mph, and you have the sensor on a left wheel, your speedo may read e.g. 60mph - this is because the outer wheels travel further and therefore go faster. At the same time the inside wheels will be going at 40mph. (the differences aren't accurate but you get the idea).

Now, if it's on the prop shaft, then it'll usually be an average value of the left and the right wheels, which will give a more accurate representation of the actual speed.

HTH,


Sy

[Edited on 7/2/06 by gingerprince]

If you want to do it properly then you should have one on each of the front wheels and average them

I sandwiched a trigger wheel between one of my diff output flanges and its lobro joint.

it's not the horrible brass thing is it about 5/8 thick and about 4 inches long is it. I tried one of them but it was to big and awkward to mount so went for the 6 magnet system the pickup is about 1/4 diam and about 1 1/2 inches long mounted on rear upright theres a pic in the MK blade section of my photo archive
regards
tony

Used the big Brass thing, mounted it on a bracket mounted on the 3 gear lever bolts, then I made a toothed washer about 3" diameter, and spot welded on the propshaft in front of the forward UJ.............

Sorry, I should have mentioned that my car is a middy so no propshaft So a wheel pickup is my only option unless I resort to the speed sensor on the gearbox (if its compatable)

Yep, its the huge brass thing and it really is a pain to find somewhere right for it. There are no magnets involved though so I suppose it could be worse.

If I drill out one of the tapped holes on the upright that would have been for the splash plate, I should be able to wind in the M10 sensor to within a couple off mil from the hub bolts ...... but I'm worried it will weaken the upright with such a large hole. Maybe I ought to use the gearbox sensor after all The MK one sounds like a much better option although it is a different kind of (magnetic) sensor so will it be compatable?

If I remember correctly fitting the speed sensor to the front wheel is a bit of a no unless you have a certificate showing the accuracy of the speedo. This is because the SVA tester can't check the speedo during the test. The gearbox output would be the best way to go. Give the manufactures a ring they can probably help.

So the SVA man cannot test it on the rollers then? The calibration is done on the car and it is obviously different acoording to the setup (no of triggers, diameter of wheels etc) so I am going to use my gps system which seems to be more accurate than most car speedos (which have to read fast) Does that mean I can scribble out a certificate then?