Nitrous is probably dollar for dollar the best temp performance upgrade that can be done. That car is never going to be a screamer but that doesn't mean it cant give you some nice performance.
Nitrous is safe (both for the engine and yourself) when done properly. However, given the nature of it and your money situation, if you cant afford to replace/rebuild the engine, you cant afford to use nitrous. Thats just my opinion anyways.
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