Speedo calibration

[Adam]

Swapped a SRi speedo into my GSi clock set today.
But noticed that the SRi speedo has a different calibration number than the GSi one.
GSi-w1810
SRi-w1849

My original speedo in the car was also w1810.
So the SRi is different.

Is this going to make my nova speedo even more unreliable? Lol
I dont want to go through a speedo cam doing what i think is 29mph when im actually doing 45.
:thumb:

[Stuart]

Tyre size (or even better measure the centre of the hub to the floor)
Gear box cluster (F10/13 C/WR)
FD Ratio #
please.
And i assume you have a rev counter (although these are a little unreliable)

[Adam]

195/45/15
F10
3.74 or 3.94 cant remember which.

Yes i have a rev counter.

[Stuart]

3.74 fd

3rd gear 30mph = 2250Rpm

3.94 fd
3rd gear 30mph = 2350Rpm

gnats cock of a difference with the FD's lol

[Adam]

Lol
What do the different W .... numbers mean?
Something to do with the FD ratio?

[Stuart]

Close Ratio or Wide ratio.... im not sure there was a close ratio F10 lol

[Adam]

So could the SRI clocks, w1849 be off a F13CR?
And so it shouldn't affect my speedo that much if the FD aren't that much different.