You can't and have no reason to do so. This car wil run over 100 mph and the speed is computer comtrolled.
You take it to a Volvo Dealer and they plug in a laptop and reprogram some parameters on the ECU in the truck.
There isn't a governor. There is a REV limiter that cuts fuel pressure back at a preset speed. You would have to reprogram the computer to override it.
Change the parameters in the engine ECM
The speed sensor on a 1999 Saturn SL1 is under the transmission. It is below the fittings for the transmission cooler lines.
Speed limiter on the 01 is 107. I don't know if the 99 is any different.
128 MPH limited157 THIRD GEAR LIMITER REMOVED
See link below:
You want to blow up the engine? It is there for a reason. Go to a speed shop and see if you can get a replacement chip like they have for Mustangs.
The starter for a 1999 Saturn is on top of the transmission under the air filter box. Remove the filter box for easy access.
You must remove the Timing chain cover and engine girdle.
The speed sensor is mounted in the top of the rear differential on a 1999 F150. Remove the wires, then unbolt the sensor to remove it.
Remove the instrument cluster then replace the bulbs. = =