Speedo Correction

[sl33ek]

Hi guys,

I've had bigger wheels fitted for a while now (stock to 18s) and didnt think anything of it. Anyway during a highway trip I made sure I stuck to around the 110km/h speed limit but my friends who were following me were telling me I was speeding, doing 120 (double demerits), and it hit me that its because of the wheels.

Just want to know if anyone has had their speedos corrected, is this a DIY job? if not who does it in Sydney? Approx cost as well.

Thanks!

[B0oStEr]

If your tyres are the correct profile they should be the same rolling diameter as the stock tyres and therefore not affect the speedo reading.

If they are oversize I think there is an electronic kit (Jaycar?)that can vary the speed sensor output to correct the speedo.

I could be wrong.

Do a search.

[sl33ek]

Ok I did a search and picked up a few threads about it. This thread seems to sum it up.

http://www.skylinesaustralia.com/forums/in...wtopic=1461&hl=

Looks like its pretty involved for a DIY job

Has anyone got theirs corrected by a specialist in Sydney?

[blind_elk]

Maybe your friend's speedo reads over the real speed (which is the usual level of inaccuracy of speedos).

If you have fitted the correct replacement 18" tyres, then the speedo reading should not have varied significantly. Ask the tyre place to show you the manufacturer's specs on the tyres you fitted compared with the tyres you replaced.

[cowie165]

I DIY'd in my 180SX and would be happy to help if I can.

Perhaps you could duck in to JustJap and have a look at an R33 cluster and see if it has the trim pot so you can adjust yourself.

With hindsight though, if I faced the same problem again, I would just go and buy the correct profile tyres.

Cheers dude, good luck sorting it

[m&m]

Is the speed displayed on a Commander h/set accurate?

Mine reads about 10km lower than speedo at 100kmh.

[MR R33]

when i bought my nismo 300km/h speedo it was out by half eg when i was doing 60 it would show 120. i bought a digital speedo corrector from jaycar and it did the job. you have to build it yourself but i just took it to an autoelectricain, the only one who could do this as i asked around. if you want pm me and i will give you the details of the guy.

btw im in sydney also.

dave....