If you cut the speed sensor wire before the ECU and after the speedometer, then your speed cut will be gone. You still have your speedo because the speed sensor sends it there first, then to the ECU. Your tach is not related at all so it doesn't affect it. I have had mine cut for almost a year now with no ill effects. I had to cut it because my speed sensor is the wrong one for my engine/chassis combo (S13/S14) and so it was reading twice the speed and I would hit the cut off at ~60MPH. Use this information at your own risk.importmyth01 wrote:I bought an hks sld (speed limit defencer) and installed it and nothing changed I still top out at 98.7 in 4th gear at about 6.5k rpms. It states on the box that its meant for s13s but maybe its just me yellow wire with green stripe is speed sensor right?? what happens if you just cut the speed sensor wire??