theconrodkid
|
| posted on 19/12/06 at 04:48 PM |
|
|
speedo
got my eye on one of these speedo,s https://www.pmtuning.co.uk/index2.htm (rxin)
it mentions wheel dia from 1-2.5 meters,my wheels are 1.8 meters in dia.
i cant put the sensor on diff pinion as it will be spinning too fast and make speedo read fast,only option i can see is to put sensor on a back
wheel/brake drum.
surely this will give a lumpy reading at low speed,any clever ideas on how to do it,where to mount magnet etc? 
[Edited on 19/12/06 by theconrodkid]
who cares who wins
pass the pork pies
|
|
|
|
|
BenB
|
| posted on 19/12/06 at 05:06 PM |
|
|
Unless I'm being really stupid why not magnets on the front wheel with the sensor attached to the wing stay bracket?
|
|
|
02GF74
|
| posted on 19/12/06 at 05:14 PM |
|
|
quote:
Originally posted by theconrodkid
got my eye on one of these speedo,s https://www.pmtuning.co.uk/index2.htm (rxin)
it mentions wheel dia from 1-2.5 meters,my wheels are 1.8 meters in dia.
i cant put the sensor on diff pinion as it will be spinning too fast and make speedo read fast,only option i can see is to put sensor on a back
wheel/brake drum.
surely this will give a lumpy reading at low speed,any clever ideas on how to do it,where to mount magnet etc?
[Edited on 19/12/06 by theconrodkid]
the linky doesn't show the speeod.
and that is bollock, a 2 m diameter wheel?  you're looking at dumper trucks, a 6 ft man is 1.85 m tall.
re: following post, putting on front wheel - how do SVA test that? As far as I know, they have 1 roller so unless you have FWD, can't see how
you can do it.
|
|
|
BenB
|
| posted on 19/12/06 at 05:16 PM |
|
|
Do they mean circumference?!?!
2*pi= roughly 6, so a 2M circ wheel is 2 feet diameter...
|
|
|
flange nut
|
| posted on 19/12/06 at 05:17 PM |
|
|
The problem with using the front wheels is that at SVA time the tester can't check the speedo accuracy. You have to have documentary proof that
it's accurate. If your cars been through the SVA then no problem.
Geoff
|
|
|
theconrodkid
|
| posted on 19/12/06 at 05:23 PM |
|
|
sorry thats circumference is 1.8m according to my trusty tape measure and it has to be taken from a driven wheel or it cant be checked
who cares who wins
pass the pork pies
|
|
|
02GF74
|
| posted on 19/12/06 at 05:27 PM |
|
|
quote:
Originally posted by theconrodkid
sorry thats circumference is 1.8m according to my trusty tape measure and it has to be taken from a driven wheel or it cant be checked
I knew that really 
I think it is a non starter - it is for mopeds and these have wheels the size of coat buttons; if it were ther other way round, you could get away
with 2 magnets and put in 1/2 the circumference measureent.
One possiblility is a PIC to modify the pulses - what is max speedo reading? (it has to show at least what you car is capbable of for SVA)
nd why are you set on this one?
(still not able to see it via the linky)
|
|
|
theconrodkid
|
| posted on 19/12/06 at 05:43 PM |
|
|
click on "koso range" and its RX1N,cheap and does all the functions
goes to 223 mph....should be adequate
[Edited on 19/12/06 by theconrodkid]
who cares who wins
pass the pork pies
|
|
|
BenB
|
| posted on 19/12/06 at 05:50 PM |
|
|
On my first SVA test I presented the car with a bike speedo driven from the front wheel and they said they'd accept it as long as it seemed to
be accurate on a drive round the car park..... Probably not what most examiners would do but hey.... Else if you've got IRS, you could mount a
sensor onto one of the lower rear wishbone bolts...
|
|
|
theconrodkid
|
| posted on 19/12/06 at 05:58 PM |
|
|
ive got a live axle so no chance of that,my first sva tested it at about 4 speeds and i had to twiddle with it to get it right.
could put 2 magnets on and use KPH screen and adjust so that its reads right just says KPH?
who cares who wins
pass the pork pies
|
|
|
paulf
|
| posted on 19/12/06 at 08:20 PM |
|
|
Could you fit the sensor through the brake backplate and a magnet on the hub flange somehow? .I considered doing it when i fitted a bike speedo but
ended up using the front wheel as i didnt need to worry about the SVA.
Paul.
|
|
|
theconrodkid
|
| posted on 19/12/06 at 08:29 PM |
|
|
as the magnet is being fitted to steel/iron,both being magnetic,will the sensor know where the magnet is?
who cares who wins
pass the pork pies
|
|
|
SixedUp
|
| posted on 19/12/06 at 09:29 PM |
|
|
quote:
Originally posted by theconrodkid
as the magnet is being fitted to steel/iron,both being magnetic,will the sensor know where the magnet is?
Yes.
Cheers
Richard
|
|
|
02GF74
|
| posted on 20/12/06 at 09:15 AM |
|
|
going back to 1st post; the wheel diameter corresponding to the numbers quoted are 397 - 573 mm.
A 195/50 R15 wheels comes in at 576 so you would be under-reading by 0.5 percent.
So you could just get away with it, fit a lower profile tyre, e.g. 195/45 or smaller tyre.
About the sensor/magnet thing and cast iron(?) drums.
Depends on the sensor type, if it is reed switch then I think it should still work - the cast iron isn't going to "suck" the flux
away - the magnet will still should be able to pull the reed switch closed since one end of the magnet is still open to air (you need to put a
ferromagentic metal across both pots to "short it out" .
|
|
|
theconrodkid
|
| posted on 20/12/06 at 07:11 PM |
|
|
ta for the info,ill be on the blower in t morning.
who cares who wins
pass the pork pies
|
|
|
.jpg)
