What does the Super Nitrous do in CSR Racing 2?

I have been playing CSR2 for a little while, and have recently defeated the Tier 1 leader, KJ. However, afterwards he challenged me to a race where I wager the gold I won from beating him for his car. I chose to take him up on it, and then I was told I'd have no hope without first getting Super Nitrous - which costs real money. So I brought it and managed to win the car from KJ.

What I want to know is, does the Super Nitrous stay, and if so what does it do... Or is it only for the races where you're racing for the cars of those you have beaten?

Solution 1:

From my experience with these kind of racing games on mobile devices it is almost assured that this super nitrous boost is not permanent and only lasts a short amount of time. I couldn't tell you the specific amount of time but many similar games last around 10 minutes or for that specific race.

Edit

After looking through a lot of posts on reddit about the super nitrous it will only last for the boss races, and that is it. After that it goes away meaning you'd have to buy it again for future boss races.

Wiki states about super nitrous:

Boost nitrous is a more powerful, special nitrous that can only be obtained during a high stakes boss race. The agent will ask the player to buy it, noting that the crew leader will be a lot harder. It does cost real money and the player may choose to decline. However, it is very powerful.

Source: http://csrracing.wikia.com/wiki/Parts