HKS didn't work out they are model specific.The person I talked to told me about Split Second web site
www.splitsec.com and they make frequency clamps and voltage clamps.The speed sensor on a saturn has 10 volts or more,the sensor is permanent magnetic variable reluctance,transmits 16 pulses per revolution and has a resistance of 700-900 ohms.I was asked to call back and talk to there owner and designer on Wed this week.Is it the fuel pump that is cut or the ignition that is cut when speed limited is activated? Thanks again Chris