So I bought a Dodge Challenger '70 and I bought a few upgrades but I get stuck in 4th gear at like 130 mph but with my upgrades I have like 600 something horsepower so I should be going alot faster. But it's like the car revs up to the red mark, and revs down a little and then back up again. But do I just need to get rid of something or buy somehing else?