Guys,

 

How easy is it to convert from KPH to MPH?

 

Also, if the car has eighteens on it how much will the new speedo be out?

 

Cheers

I recently did it, it was tricky but not too bad.

 

Is yours the standard 180 km/h jap speedo or 120mph?

I have a 120 MPH speedo - and want to do the same. At bruntingthope I manages to go off the clock right round to 3PSI lol

It is the Jap one.

 

btw that picture of Clarkson, scary :eek:

 

I recently did it, it was tricky but not too bad.

 

Is yours the standard 180 km/h jap speedo or 120mph?

lol, yep sounds like me, well you'll need a new face plate first. i don't know if zcentre sell them? anyone?

 

I got mine off the for sale section here, had to put a small slit up to the hole to slip the the shaft of the speedo needle through. You should really take the needle off holding the shaft in position with a pair of tweezers but i didn't have the balls to do it :P

It is the Jap one.

 

btw that picture of Clarkson, scary :eek:

 

hehe couldn't help but put it on :D

 

Well if it's already a 180mph speedo all you have to do is change R10 on the circuit board on the back for a 2.2k Ohm resistor (small blue one ask at maplins) and job done.

 

If you do a search for it you'll find a detailed articale on how to do it somewhere on here with photos

3 options for this. Chance the face to a 120mph calibrated one, but this obviously limits you to 120 on the clock, with stock ecu you will still be stuck at 112 too.

 

Next up is an electronic convertor. Pretty easy to fit these, will convert it to 180mph, and increase the speed limit to 180mph too. However, it makes your steering lighter, your HICAS to work wrong and autoboxes sometimes go a bit mad with them on.

 

Finally you can do some techy electronicy stuff with the speedo to somehow recalibrate it to 180mph, while not affecting any of the other systems.

 

Oh and you could also just buy a set of UK clocks but these are rare and expensive.

there is a pair of uk clocks with carbon fibre surround in the for sale section

 

http://www.300zx.co.uk/forums/showthread.php?t=78832

Fasten a solar powered calculator on the dash and enter speed then divide by 1.6.

 

Total cost about £10! :rofl:

Also, if the car has eighteens on it how much will the new speedo be out?

No affect. When you fit bigger wheels, you fit lower profile tyres to keep the same rolling radius.

 

Fasten a solar powered calculator on the dash and enter speed then divide by 1.6.

 

Total cost about £10! :rofl:

An excellent idea...expect for one flaw.... what would you do at night !

I've a speed converter on my NA and a gps speed trap device (roadpilot) and the speed reading on the (now) 180mph dials is spot on up to 80+ then marginally fast thereafter.

 

Also I've driven NA's without and with converters and to my knowledge they don'y affect the steering - I wouldn't know about the HICAS.

 

Fitting one is quite easy, do a search for Speed converters and you'll find a wiring diagram from Z World (I think). Follow that. And the dial backs can differ from the pictures posted on the Forum, so splice into the wires as these are the same from year to year (in my experience).

 

I bouch a converter from cbr (thanks very much) for £40 delivered.

 

Good luck

 

Jack

An excellent idea...expect for one flaw.... what would you do at night !

A bright interior light!

If you're handy with a soldering iron, then take the clocks out and change the R10 resistor. The Jap spec clocks have a 33K ohm one in, replace it with a 20K one and hey presto the clock reads MPH.

 

There are a couple of Pots on the clocks as well, one will adjust the speed at which the bong noise (sorry can't think of any better description) comes on and the other adjusts the speedo accuracy, so if you find it's still out by 5% or so, you can adjust that pot.

 

I have a few spare 10K resistors if you want one.

 

Gaz

If you're handy with a soldering iron, then take the clocks out and change the R10 resistor. The Jap spec clocks have a 33K ohm one in, replace it with a 20K one and hey presto the clock reads MPH.

 

There are a couple of Pots on the clocks as well, one will adjust the speed at which the bong noise (sorry can't think of any better description) comes on and the other adjusts the speedo accuracy, so if you find it's still out by 5% or so, you can adjust that pot.

 

I have a few spare 10K resistors if you want one.

 

Gaz

 

 

Thought it was a 20K resistor?

Thought it was a 20K resistor?

 

Yes it is sorry, bit of a slip on the keyboard there, well spotted.

 

I have a few 20K resistors should anybody want one.

 

.

Crap i did it again didn't i? i'm obsessed with 2.2k ohm resistors lol yes 20k is the right one :D

Does the resistor replacement also remove the 112mph speed limiter like the little speed converter box does??

10 + 10 = 20

Does the resistor replacement also remove the 112mph speed limiter like the little speed converter box does??

 

Don't think so but a chipped ECU will :)

aww well i donr the resistor trick tonight and it works great but yes i have a speed limit again :(

 

anyone point me in the direction of a chipped ecu? or another way to remove the limiter

?

hi all

new on here and a zx virgin or was till i bought one can anybody help with a wiring diagram or wire colours for the speed chip come delimiter i have the red and black that are the power grey and yellow for speed and a green one but not sure where this goes.

look forward to any info on this

Just so people know, I have done the resistor mod now, and the results were WAY out, reading 100mph at 70. Anyway there is a small potentiometer on the top of the PCB, you can make a hole in the plastic above it (i did it in situ by stabbing the soldering iron through :p), you can then calibrate it while driving by turning the screw, probably best to have a passenger do it though ;). Results after this were accurate.

aww well i donr the resistor trick tonight and it works great but yes i have a speed limit again :(

 

anyone point me in the direction of a chipped ecu? or another way to remove the limiter

?

have a word with John Dixon from here, he will sort you out for a good price.

K.Wales,

 

Have a look Here

 

Think this is what you are after.

 

Colin

Or do the proper conversion and fit a set of UK clocks - http://www.300zx.co.uk/forums/showthread.php?t=91320 ;)