Nismo Speedo

[skygo2xs]

Hi all,

My V35 has a Nismo 280km/h speedo, with the gps, the speedo is out by between 6 - 14 km/h. I recently removed the speedo and took it to an instument specialist who was unable to do anything with it to calibrate.

Anyone have any ideas or experienced this problem?

Thanks

[rs73]

does ur car has after market rims and t7res? if so, what size?

any after market lsd?

I used to have a 300km/h speedo on the old gtst and it was out by about 10km/h but that's because I have after market rims, and the car has 4:3 diff instead of std 4:11 diff

[chook]

This is the only speedo corrector I have found that works with Nissan's unique AC speed signal.

http://www.jaycar.com.au/productView.asp?I...mp;form=KEYWORD

http://www.gtr.co.uk/forum/111435-speedo-c...ed-r33-gtr.html

[dannyw]

This is the only speedo corrector I have found that works with Nissan's unique AC speed signal.

http://www.jaycar.com.au/productView.asp?I...mp;form=KEYWORD

http://www.gtr.co.uk/forum/111435-speedo-c...ed-r33-gtr.html

I am always worried and conscious when changing to new tyre sizes, but does it mean now with this item, i can buy any tyre size i like, then correct the difference(required by road law)? Or is the item also illegal to be used, just like wrong tyre size with more than 5% difference in reading? (which i hope not)

[chook]

nothing illegal about it, corrects in 1% increments. Its a bit confusing to program it, but works perfectly once setup correctly, there are better commercial units around, but none i know of work on Nissans.

[n15m0]

first things first.

What tyre profile are you running currently. Most speedos read inaccurate because you are running the wrong tyre profile hence upsetting the factory overall diameter. Nothing much to do with aftermarket wheels.

QLD laws state that your OD cannot vary by more than +- 15mm. Over or above this you will get significant inaccuracies with your speedo, either reading too fast or too slow.

Here is a useful calculator you can use to determine if you are within factory specs.

http://www.1010tires.com/tiresizecalculator.asp

[Oaksey]

Within 6-10km is normal, I think the ADRs say it has to be within 10% Yes as has been raised many times this is stupid because your speedo could read 100 and you are actually doing 110, it would meet ADR but you would still get a fine. Thing is basically all speedos overstate your speed. I think TT/ACA did a test once and Jeep Cherokees speedos said 120 when they were doing 110.

That said, I guess if it was out by as much as 10km/h it would be annoying.

Edited April 22, 2009 by Oaksey

[PhilKenSebben]

Yeah you gotta love the way a car can be up to 10% out and ADR will pass it, but the cops will happily fine you for less than 10% over the speed limit. hmmmm.

Like all the defect rules that exist yet when a prominent organisation suggested that a police Honda motorcycle, due to it's non-symmetrical excess mass (sirens, lights, etc) was unsafe above 130 km/h, it was ok.

Or that "there's no such thing as safe speeding, every k over is a killer", yet police will reach huge speeds to get to a bank that's been robbed of it's fully insured money, but that's acceptable.

Almost as if they're screwing us.....

[rs73]

since most factory speedo are around 4-6% overstated from the factory, when changing rims n tyres you could probably do a bit research and maths and try to get a tyre size that's about 5% larger than factory diameter, that should bring the accuracy up to about 1% between speedo and actual travel speed

[skygo2xs]

thanks everyone for the input, my car had the factory 18's when I got it and the speedo was out pretty much as it is now. I presume the diff etc is standard as the car appears so. I changed the wheels to 245/40/18 = lower profile from the 45. This made the speed out by probably 1 more km/h.

ill have a look at some of the ideas in the links given and see how I go but yeah, up to 14 km/h is frustrating.

thanks

[BLISTC]

dont waste your time or money mate.

just dont speed!

[chook]

dont waste your time or money mate.

just dont speed!

huh ?... I think the whole point is to correct the speedo so he doesnt speed.

[skygo2xs]

yeh thats right, the speedo isnt giving a true indication of the speed. After speaking to the instrument tech, I think a speedo corrector device wont work as the speedo is controlled by the vehicle Canbus which the V35's have.

[chook]

You could intercept the signal before this, between the gearbox sensor and the canbus.