Evo što sam našao na forumu http://www.volvo-forums.com/t18639-1997 ... -tracs.htm
Odgovara onome što su napisali Grim, Zox i Nenad (hvala dečki
) tako da mislim da je s ovim definitivno sve rečeno.* * *
1997 Volvo - Swapping ABS w/o TRACS to ABS w/ TRACS
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I currently own a 1997 Volvo 850 Turbo Sedan WITHOUT the Tracs option.
I have been led to believe that I can simply SWAP my current ABS module Without Tracs for an ABS module With Tracs. (I will swap with a 1997 ABS module With Tracs).
I will also obtain the Switch that installs in the Dash.
Is the SWAP as simple as this?
I have also been led to believe that the ABS sensors (that I currently have at my wheels) will work with the new ABS module With Tracs. That is, that my current sensors enable the Tracs option to work.
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The Trac's systems on these cars are pretty much worthless.
It only applies a slight amount of brake pressure if it detects slippage.
But I have it on the Yellow R and can burn the tires off in the rain with it on.
I can also spin them in the dry with it on as well.
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Yes, I have seen the swap done. Just need to change the ABS module. And as for the switch, the wiring, behind the dashboard is already there, just attach the TRACS knob and you're set.
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Dakle izvedivo, ali diskutabilne upotrebljivosti.
Na koncu proizlazi da bi mehanička špera bila jedino pravo rješenje za zimu i zagorske brege
Još budete na kraju Mrky-a nagovorili da ugradi tracs,a ja bum zadovoljno trljal rukice 
