The V8 Owners Forum -

Hotwire Tune resistor wire colour and ohms rating.
Hope this helps,

NO resistor Limp Mode.

RED 180ohm - Australian 3.9 cat.

GREEN 470ohm - UK non cat.

BLUE 1800ohm - Gulf states 3.9, or Europe & UK 4.2 non cat.

WHITE 3900ohm - Europe & UK 3.9 (or 3.5 Disco) Catalyst

Thanks Tony, as I am not using a cat I would think the green one would be the one to go for ?
Its all a bit of mystery though as I cant grasp how a resistor fuels the engine under various load conditions !
Regards
Ian

Just had a look on ebay and there is a blue one and a white one on there from the same place at 20 and 25 quid - but alas no green one !
Regards
Ian

If one knows the resistance value (which Tony has kindly provided), a trip to Maplin to buy a suitable resistor is by far the cheapest way to do it. Then you just have to wire it in.

The resistor doesn't directly affect the fuelling. The ECU reads the resistor value, and selects a fuel map / other operating parameters depending on the value. The spectrum of resistor values will be divided up into bands, so the exact value doesn't matter.

This is a normal technique to enable selection of more than two values on a single input wire. If there were only two maps, one would have link / no link. But more than two, and you do it like this.

Chris.

So

If you put in a variable resistor that changes between the min and max above

Could you literally change the map on the go by turning a resistor?

Ian

I don't see why not. Only that the ECU probably reads the resistor once when you turn the ignition on, so map switching 'on the fly' may not work. You might have to stop the car first.

Chris.

koopsterman wrote:Just had a look on ebay and there is a blue one and a white one on there from the same place at 20 and 25 quid - but alas no green one !
Regards
Ian

How much?!!

Maplin is your friend...http://www.maplin.co.uk/p/metal-film-2w ... stor-d470k

44p...