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The mkiv Supra Owners Club

UK spec Speedo


Nic
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Did the UK spec have the digital odo featured on the pre-facelift J-Spec or did it have a physical old skool rolling numbers unit inside the speedo, like the facelift J-Spec?

 

pre-face lift and UK spec are practically the same, only small differences are the symbols on the R/H side dial (fog light etc..)

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They are exactly the same fit and mean you don't need to convert the speed signal in a J-Spec, as the UK speedo automatically turns it into miles internally.

 

I installed one as well as altering my Odo to display and clock-up in miles, so there's no need for any kph-mph converters. :)

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Mike,

 

Are you sure about that, I seem to remember that the signal for the speedo goes from the Odo which is why, when you instal a converter at the Odo end(do not under any circumstances fit any of the fleabay converters that are fitted at the speed pick up at the gear-box), the speedo automatically reads in miles per hour................giving you a speedo that reads up to 180MPH.

 

The reason your conversion "worked" is because you installed the Odo with the UK speedo. Fitting a UK speedo and leaving the KPH Odo in place will NOT give you an MPH speedo!

 

The only change necessary to make to the speedo is to fit the little "MPH" transfer over the "KPH" on the head.

 

If there are any lingering doubts about this contact NCS-Systems, who market "proper" converters(not the fleabay cr*p), at 01509 670 707 web page http://www.nce-systems.com

 

I bought my converter from them and I now have a 180Mph speedo, which is in keeping with it being a "performance car".

 

Rgds

George

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Are you sure about that, I seem to remember that the signal for the speedo goes from the Odo which is why, when you install a converter at the Odo end the speedo automatically reads in miles per hour................giving you a speedo that reads up to 180MPH.

The reason your conversion "worked" is because you installed the Odo with the UK speedo. Fitting a UK speedo and leaving the KPH Odo in place will NOT give you an MPH speedo!

The only change necessary to make to the speedo is to fit the little "MPH" transfer over the "KPH" on the head.

If there are any lingering doubts about this contact NCS-Systems.

I bought my converter from them and I now have a 180Mph speedo, which is in keeping with it being a "performance car".[/Quote]

 

Almost - but not quite. The original speed signal from the gearbox splits behind the dash. One feed goes to the speedo directly and the other to the Odo.

 

The speedo feed is totally separate and hence a UK speedo will register Mph without any speedo converter.

 

Because you are not altering the other feed to the odo will still be interpreted into km. For most people this is not a problem, as it keeps the odo on one unit of measure, so you can claim it as an accurate reading.

 

The re-transmitted speed signal from the odo (which is what you're thinking about) goes to the ECU, CC, Active Spoiler and PPS. Leaving that unaltered means these will operate as designed, because they are getting a signal that is un-corrupted by a converter.

 

Part of the installation of any (good) converter is the provision of a separate 1:1 signal feeding this wire (pink) to keep all these functions normal.

 

If, however, you do want the odo clocking in miles, then you can either wire a converter into the odo (in which case you might as well wire it into the speedo as well and not bother buying a UK one in the first place!), or you can convert the odo to read in miles by

 

1. Swapping 2 resistors on its circuit board (this switches the odo to clock up in miles and also makes the display say 'miles' instead of 'km')

 

2. Reset the odo to display the adjusted total in miles (I used NCS to do this funnily enough). If you do this you are legally bound to inform anyone buying the car that the mileage has been tampered with.

 

This leaves you with a car that has no aftermarket wiring knocking about, which displays MpH on a UK 180 MpH face, clocks up in miles with a correct reading (in miles) on the odo and leaves un-touched the CC, PPS, Active Spoiler and ECU feeds. :)

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  • 1 month later...

I'm with you on this one Mike.I too totally removed my speedo converter and fitted a UK spec speedo, and performed the UK spec odometer mod.

 

My MPH readings are now accurate and i have have no problems what so ever. :)

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