no ur stuck with either trying to get more air/fuel into the engine with either forced induction or nos, u can make ur car more efficient with headers, lightened flywheel, better clutch, or make it work easier so it'll crank out a little more power with lightenning internals, u can possibly get a more aggressive crankshaft with larger lobes to crank out more power but i dont know where u'd begin to get started all think of what u want for ur car and start making a plan. cars are expensive, 900 bucks won't take u very far if u want a big power increase, unless u go with nos but then ur getting dangerous if u want alot of power, and ur losing dependablity but hey if its a tradeoff ur willing to take go for it