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Speedohealer Calculation
001Ben - 27/8/08 at 08:28 PM

I have just purchased a speedo healer to adjust my speed in my kit.

Does anyone know what the calculated value is for the following :

R1 engine (2001)
3.54 Diff
205/60/13 tyres

charlierevell - 27/8/08 at 08:47 PM

Do you have GPS? Would make it very easy!

001Ben - 27/8/08 at 09:01 PM

no i dont have GPS but was thinking that I could borrow a tom tom from someone at work with it on.

Johneturbo - 27/8/08 at 10:11 PM

Just follow someone through a 30mph speed camera, then you'll know your doing 25mph

Paul TigerB6 - 27/8/08 at 11:43 PM

i just had a go using the online calculator and got -29.5%. Does this sound about right to others???

02GF74 - 28/8/08 at 07:15 AM

as I am sure you know, speedo healer reads frequencey of pulses in (from sender) and scales them either up or down (to the speedo).

You do not give any information about the sensor you are using nor any information about the speedo, which make it quite difficult to come up with an answer.

to calucalted pulses from sendersee here

you then need to know what the pulse reqirement of the speedo is - usually it is number of pulses in 1 mile.

knowing the two numbers will give you a scaling facter that you then need to look up in the data sheet for the healer and configure the switches.

Paul TigerB6 - 28/8/08 at 08:10 AM

quote:
Originally posted by 02GF74
You do not give any information about the sensor you are using nor any information about the speedo, which make it quite difficult to come up with an answer.



Ben cant get on here while in work but i've been doing most of the wiring so will answer.

I'm afraid you have really confused me with this. I thought it would be a pretty simple question for someone with the same setup - ie standard R1 engine (with the standard speedo sensor), an Escort 3.54 axle, 205/60/13 (R888's) and standard R1 clocks. I thought a Speedohealer was only used to convert the output from a standard bike sender to a set of standard bike clocks anyway??

I had no idea that the number of pulses would be needed when just trying to take into account the different gearing (I tried to get as close as I could using the sprocket counter on the Speedohealer site) and tyre size.

Anyone help??

[Edited on 28/8/08 by Paul TigerB6]

02GF74 - 28/8/08 at 08:49 AM

I am answering a generic speedo healer principles.

the sensor will be take off the gearbox final drive and supply pulses to the speedo.

the pulse frequency is dependent on how fast the outpust shaft is spinning and the speedo is calibrated according to factory sprokects and wheel diameter.

change any of those and the speedo will not read correctly.

this is wha you have done by putting on a diff and using car tyres.

therefore to get correct speedo reading a healer converts pulse frequncy from the sender to another frequency to the speedo.

now that you have told me a bit more about the set up, I see I was wrong about speedo pulse input - no need to know that.

knowing the rear tyre diameter and number of teeth on both sprockets it should be possible to work out the ratio of adjusment.

Paul TigerB6 - 28/8/08 at 09:18 AM

Well the 2000 service manual says the sprockets are 43/16 (Speedohealer site defaults at 42/16 so i've just recalculated as i didnt change this last night) which is 2.688:1. The manual also confirms the standard tyre for the bike as 190/50/17.

Using these figures and changing the tyre size on the Healtech Speedohealer website online calculator to 205/60/13, and the sprockets to 60/17 (3.53:1 - near enough to the 3.54 diff) gives a correction figure of -33.1%

Does this sound about right anyone?? The car is having a rebuild so doesnt get an SVA to check it out.

Jubal - 28/8/08 at 09:33 AM

Here's what I did. I took the theoretical top speed of the bike in 6th at max revs, and using the readily available spreadsheet on here, calculated the top speed of my car in 6th at max revs, using the parameters like wheel size, diff etc. The scaling factor is the percentage difference between the two. Very simple and will be quite accurate.