My speedo has packed up in my jap n/a. Odometer still working. Still nothing when chip removed (back to kmph). Reckon speedo head must be knackered ?? I have found a British instrument set that came out of a TT. Will that go straight in and read right without the chip ? do I still need the chip to delimit ? Thanks a lot .:helpsmilie:

My speedo has packed up in my jap n/a. Odometer still working. Still nothing when chip removed (back to kmph). Reckon speedo head must be knackered ?? I have found a British instrument set that came out of a TT. Will that go straight in and read right without the chip ? do I still need the chip to delimit ? Thanks a lot .:helpsmilie:

 

 

Will fit straight in, will work WITHOUT the delimiter and read miles per hour, however the top speed limit (112 mph )will still be in place, changing the chip in the ecu will sort this.

 

Jeff TT

Thanks Jeff. I would prefer to just put another Jap speedo head in my binnacle because its very low mileage and has also had a brushed ally front fitted. Cant find one. Have resoldered mine but still no joy. Any ideas buddy ?

im selling a jap tt one

So, let me get this right...........

 

A set of UK clocks fitted to a JDM car will read MPH but not remove the 112 MPH limiter?

 

A 'chip' off eBay installed will convert the JDM speedo to read MPH AND 'remove the 112 MPH limit?

 

Or is there another chip I'd need to replace?

So, let me get this right...........

 

A set of UK clocks fitted to a JDM car will read MPH but not remove the 112 MPH limiter?

 

A 'chip' off eBay installed will convert the JDM speedo to read MPH AND 'remove the 112 MPH limit?

 

Or is there another chip I'd need to replace?

 

The Jap spec car is limited to 112mph.

The 'chip' convertor off ebay or anywhere else converts the JDM speedo to read MPH by simply taking the speed sensor input and reducing it by approximately a 1/3rd. By doing this the main ECU is tricked into thinking the car is going 1/3rd slower than it is hence not limited to 112mph. This is because the speed sensor feeds the clocks 1st then the clock tells the ecu how fast the car is going!!

So really the car is still limited, but not at 112mph because the ECU thinks you are only going around 75mph! The car is still limited, but at a higher real value.

 

Fitting UK clocks just means no convertor chip is needed. The speedo reads correctly, but more importantly tells the ECU the true speed. So the car is still limited to 112mph.

A proper reprogrammed EPROM that fits in your main ECU is the true way of delimiting the car, the limit can be raised to the programmers discretion.

By using the UK clock method, the PAS ecu and auto ECU if applicable will also get the true information and behave correctly.

(PAS is speed sensitive, using the jap clock chip converter feeds the PAS ecu 2/3rds real speed and makes it lighter than it should be, I think the autobox ECU also uses a speed signal to help the changes).

Edited August 4, 201015 yr by turbocraigy