When the speedo is converted to MPH (using the cheap method), does the odometer and trip counter continue to rack up the distance in km or does it start using miles?

I have just had mine done & seems to be clocking in MPH.

cant be 100 % sure though but will keep an eye out!

The "cheap" method robs one in three of the electronic signals from the speedo sender, so everything that is run off that signal will be running at two thirds, which is an approximate calibration from km to miles.

 

Couple of points that were made to me when I did it at first (and the reason why i eventually went for uk clocks)

 

It is not an exact figure, so you may need to get your speedo recalibrated

 

The idea of robbing everything of one third of the speed signals, including the ecu, worries me, if the ecu doesnt know what speed you are doing, how can it accurately assess the amount of fuel you need?

 

There is a 33ohm resistor on the back of the speedo which you can change for a 20ohm one which does the same thing, but only at the speedo cluster end. But to be honest i found it sat easier in my mind to change the clocks for uk, and to have the limiters removed at the ecu

 

HTH

 

hugh

The ECU I don't think uses the speed signal for anything, auto box might though?

The steering definately does, feels way too light with converter chip and the HICAS gets the wrong signal.

Originally posted by John Dixon

The ECU I don't think uses the speed signal for anything, auto box might though?

The steering definately does, feels way too light with converter chip and the HICAS gets the wrong signal.

I never thought that much about it, but it sounds quite bad really as i have a auto box, i dont know if i have the hicas though?

93 tt import

I brought my convertor about £80 from mjp on traders forum. After reading all the letters i rung him to check about mine.

He said his kit converts trip & oddometer to miles & is only wired to bypass ecu so no bad effects!

Go for his one as mine seems fine!:D

You will have HICAS on a TT.

AFAIK, all converter chips affect all the signals. The pulse signal from the speed sensor to the speedo head is the one you change, and the circuitry that modifies the signal to go to the steering etc is on the back of the speedo head, so there is no way to leave that signal untouched.

I stand to be corrected, but that's how it looked from the diagrams and tracing the tracks on the board.

Yep, unless you get one of the convertors with the 1:1 output also, then you will end up with a very strange feeling car. As John said it screws up the HICAS and PAS, also the autobox if you have one. The ECU doesn't need the signal for fueling - fueling is not related to speed ;) Again, as John said, the speedo is the first 'port of call' for the speed signal, so to make the speedo read correctly, all the other devices will be working at 5/8ths speed too. The units with a 1:1 output as well, involve finding where the speed signal leaves the clocks, to go to the rest of the systems and splicing it in there.

 

This makes no sense at all LOL

 

CheerZ,

 

Andy

Finding where it leaves is easy, problem is I don't think it's the same sort of signal. It goes through some circuitry, I was guessing it changes the pulse to a 0-X volt analogue signal for the other units.

I must admit you lot know a lot more than me with al your pulse signals & that.

But the car seems to drive well & mike from mjp is a good guy who also knows his stuff.

I know when we done the car it ment splicing in at the speedo end with some soldering, perhaps this new way sorts it as i cant see people selling minior things like that if it focks up steering,gearbox etc?