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Speedo sensor - how many bolts needed?
Banana - 4/2/17 at 08:39 PM

Does the speed sensor from a 929CBR need more than one bolt head/reference point to get its pulse from?

I've just fitted mine today, and attached one single bolt head to the outside of the flange adaptor for the prop.

Im getting a reading of 3mph when im doing about 20mph.

Im yet to calibrate the Speedo Healer, but just wondering if one pulse point will be enough to get a decent reading?

If i add another point, will it need to be evenly spaced from the other?

Looks just like this


[Edited on 4/2/17 by Banana]


CosKev3 - 4/2/17 at 09:48 PM

Is this using the standard CBR sensor?

I know with aftermarket sensors/dashes you get a more accurate reading a higher amount of pick up points,for example Koso say 4 minimum upto a maximum of 60.
I use the 6 bolt heads on the rear driveshaft where it bolts to the output flange on diff and mines bang on


Banana - 4/2/17 at 10:02 PM

Yep standard CBR sensor.

Im pretty sure it will need more of them, but is it crucial for them to be evenly spaced?

I'll go to the rear if this doesn't work, just I've already made the bracket.

[Edited on 4/2/17 by Banana]


mark chandler - 4/2/17 at 10:21 PM

I needed 9 to get close on 919 clocks without a healer.


Banana - 4/2/17 at 10:34 PM

Thanks. How have you done yours?


watsonpj - 5/2/17 at 03:12 AM

If you want to get a decent result it will be better to understand the value you have going at 60 or 70 if you can this will give you less error when you work out the final solution.

ie 3mph =20mph
but 70mph might only equal 9mph due to the additional scaling. How are you measuring actually speed.

then if you need to now how many bolts is just simple maths.

you need it tp
20/3=6.667

so you need 7 bolts evenly spaced.
2 will read 6
4 will read 12
6 will read 18 and
7 should read 21 and therefore overread by 5% the legal requiredment is that it reads speed +0% to +10% I believe.

but I really would try to get the difference at a much high speed first to check.

I tested mine (magnets) by putting them in the right spots and using lots of sellotape to hold them in place. They can be any slugs of ferrous metal to test it in your case.

Pete


DW100 - 5/2/17 at 01:22 PM

If you don't place them evenly you could end up with a propshaft balance issue.


Banana - 5/2/17 at 08:36 PM

Well i decided it would be easier to just rewire and go from the diff output bolts, instead of trying to evenly space bolt heads on the prop.

Now i am getting no reading at all. (Not driven it above 30mph, but i surely should have a some reading)

Beginning to loose patience with this.. Continuity fine, 12v fine - i even rewired with heavier gauge wire. Still naff all.

Last night i got a reading (see the opening post) so i know the sensor works.

Is there anything wrong with this? Apart from being filthy..




[Edited on 5/2/17 by Banana]


Banana - 5/2/17 at 10:33 PM

Has anyone a suggestion as to why this doesn't work?

Sensor wiring is correct, and sensor was working yesterday.

Dirty bolt heads or wrong material maybe..?



[Edited on 5/2/17 by Banana]


mark chandler - 5/2/17 at 10:59 PM

It will not like the shape of those, either mount to sensor horizontal pointing at the face of the bolt or bend some L shaped tabs of metal and stick behind the bolt so the sensor sees a nice square ede.


Angel Acevedo - 5/2/17 at 11:26 PM

quote:
Originally posted by mark chandler
It will not like the shape of those, either mount to sensor horizontal pointing at the face of the bolt or bend some L shaped tabs of metal and stick behind the bolt so the sensor sees a nice square ede.



Ditto...
I was browsing the web looking for Trigger Wheels and some examples of homemade trigger wheels had small Sheetmetal Tabs Bent to act as teeth.
You mey use Tab Lockwashers oriented in such a way that the tab acts as the teeth.
HTH
Weel not exactly.
But you´ll get the point...
https://forum.autosportlabs.com/viewtopic.php?t=2682&sid=b6d3a27f3298e4004bf6f77e30abdfdc


Banana - 6/2/17 at 10:31 AM

Yes! That is a great suggestion, thanks.

Although by the look of it, i will only be picking up half of the bolt head as the sensor will foul on the rubber boot..

If this doesn't work, i will try some tabs behind the heads.

Cheers guys.


Angel Acevedo - 6/2/17 at 03:44 PM

REviewing your picture, also make sure that the Bolt or whatever you are using as teeth covers the full face of the sensor head, not necessariy the Full plastic head.
This is, the sensor head may be a small circle in the middle of the housing.
On your picture, there´s a good third of the head off the bolt you are using as Trigger.
Regards
AA


ReMan - 6/2/17 at 04:17 PM

I'd got it in my head that the Honda sensor needs magnets, not normal metal, but I may be wrong

Don't know how much range the speedo healer has to repair, theoretically one may be enough, but as said, more is better certainly at low speed I'd have thought


Banana - 6/2/17 at 06:28 PM

I see what you mean, but if i move it more central, then i i will will have to lift it higher to go over the boss/hub. Therefore creating a larger gap between sensor and pickup point.

Im going to try and fit horizontally as suggested.



quote:
Originally posted by Angel Acevedo
REviewing your picture, also make sure that the Bolt or whatever you are using as teeth covers the full face of the sensor head, not necessariy the Full plastic head.
This is, the sensor head may be a small circle in the middle of the housing.
On your picture, there´s a good third of the head off the bolt you are using as Trigger.
Regards
AA


Angel Acevedo - 12/2/19 at 03:20 PM

Banana.
Did you ever got to fix this?
I am doing wiring and have provisions for two sensors.
The one supplied with my Acewell ant the one on the gearbox.
Acewell sensor is not installed yet and the one in the gearbox apears broken and maybe need replacement.
Thanks.
AA