We have this question being asked all the time on J-body.org... since most of the uplevel Cavalier and Sunfire cars came with the 2.4L...
Here's the J-body.org answer:
http://www.j-body.org/faq//80/
There's three ways I know of though...
1. Disable the VSS. That's the Vehicle Speed Sensor.. it's on the tranny. I'm not going to be more specific than that... if you can't figure it out, you probably shouldn't be going that fast.
2. Have someone (J-body Performance, RSM Racing, etc) reprogram your PCM with a higher speed limiter. They can't remove it, but they can raise the value on it to 255 km/h. That's plenty fast. Costs about $500 US.
3. Replace PCM with an aftermarket computer. It won't have the limiter
The only reason I know how to remove my speed limiter... is because I have to. I run nitrous... and with 15" slicks, due to the smaller tire, the car thinks it's going 108+ mph at the end of the quarter mile. (Even though it's only trapping at 100 mph)... BTW, that's a 13.8..
If I hit the limiter on the bottle... boom
oh, and yes.. I only do it ON THE TRACK. It would be stupid and frankly pointless to do it anywhere else.
...j