speedohealer R1 on 15's
Dillinger1977 - 26/9/06 at 07:38 AM
Has anyone got a speedohealer correctly calibrated to an r1 on running on 15 inch tyres?
im guessing theres a value that it applies to the normal r1 speed sensor to correct it, so if anyone has got the same setup as me I should be able to
use their settings.
I cant remember the profile of the tyres at the moment but its the ones that come on the halfords Team dynamics pro race pack. I'll check later
and update.
cheers!
[Edited on 26/9/06 by Dillinger1977]
nitram38 - 26/9/06 at 07:45 AM
You will also need your diff ratio details,
Dillinger1977 - 26/9/06 at 07:59 AM
whoops, forgot about that.
3.36 diff!
smart51 - 26/9/06 at 08:31 AM
Mine is set at -31.4% for 195/50/15s, a 3.62 diff and a 4XV engine.
With a 3.38 diff I'd have to set it to -26.5%. Your engine is a 5JJ isn't it? it may have had a different final drive ratio.
Check your tyre size and I'll work it out for you. I don't guarantee that my calculations are right but I passed my SVA with it. On a
recent track day I saw 110 MPH on the clock at 11000 in 5th. That engine speed should give 105 true MPH according to my calculations which is a 4.8%
error in the right direction.
zxrlocost - 26/9/06 at 09:10 AM
erm must be me I jut followed a car down down the road at 60 for a few miles
read what my speedo was reading then calibrated it on there website
Dillinger1977 - 26/9/06 at 09:53 AM
quote:
Originally posted by smart51
Mine is set at -31.4% for 195/50/15s, a 3.62 diff and a 4XV engine.
With a 3.38 diff I'd have to set it to -26.5%. Your engine is a 5JJ isn't it? it may have had a different final drive ratio.
Check your tyre size and I'll work it out for you. I don't guarantee that my calculations are right but I passed my SVA with it. On a
recent track day I saw 110 MPH on the clock at 11000 in 5th. That engine speed should give 105 true MPH according to my calculations which is a 4.8%
error in the right direction.
yeah mines a 5jj, I hadnt considered the engine type and gearing.. Looks like theres probably too many variables meaning that the chances of finding
a similar setup are extremely slim!
Am i right in thinking that I could turn up to the SVA with it uncalibrated, and just do it while its on their rollers?
otherwise i'd have to do the follow trick which is a bit dodgy. (testing things like brakes and speedo when you arent allowed on the road is
tricky.. :O )
[Edited on 26/9/06 by Dillinger1977]
nitram38 - 26/9/06 at 09:59 AM
They allowed me to recalibrate my digital spa speedo. The tester even calculated the % of adjustment needed.
Mine worked on tyre circumfrence so all I had to do was add or subtract the % from the starting measurement.
Coose - 26/9/06 at 10:43 AM
Using the primary (1.581:1), 6th gear (1.115:1) and final drive ratios (2.688:1), plus the standard rear tyre circumference (74.95"
I worked out
that a 5JJ R1 is geared to do 176mph at 11750rpm (the redline).
Thus,
((11750/1.581)/1.115)/2.688 = 2479.71 rear wheel rpm
2479.71 x 74.95 = 185855.98 inches per minute = 2.933 miles per minute = 176mph.
Now, if you divide by the bike the rear tyre circumference (74.95" and multiply by the car rear tyre circumference (71.24" for 195/50-15)
and multiply by the bike final drive ratio and divide by the diff ratio you get: -
(176/74.95) x 71.24 = 167.288
(167.288 x 2.688) / 3.38 = 134.712 mph @ 11750rpm.
To get the percentage reduction in speed to calibrate your speedo healer, add these figures into this simple calculation: -
(100/176) x 134.712 = 76.54%
It's as easy as that! What I would do if you want to be more accurate is find a 190/50 - 17 bike tyre and measure the circumference and replace
that figure in this calculation, along with the actual circumference of your own rear tyres.
Hope this helps to get you started! 
nitram38 - 26/9/06 at 10:47 AM
I have bought a veypor speedo/dash for my next project.
So much simpler!!!!!!!!
Dillinger1977 - 26/9/06 at 11:03 AM
blimey Coose, thats thorough!
excellent guide, much appreciated!
Coose - 26/9/06 at 01:04 PM
Well there's no point taking a stab in the dark when the figures are there for you!
Also, as far as I can see all gear ratios are the same on a 4XV too if that's any help?
amalyos - 26/9/06 at 08:58 PM
quote:
Am i right in thinking that I could turn up to the SVA with it uncalibrated, and just do it while its on their rollers?
[Edited on 26/9/06 by Dillinger1977]
I downloaded the Speedohealer software onto my laptop, then took it with me to the SVA. They let me set it up on the rollers. i.e they told me their
reading against mine, then I plugged it into the software and changed the ratio.