^^^And if you care about being competitive... If you do, you have to push your car to the edge of the rules in any class to really be competitive. If you really don't care, then the world is your oyster and you should do whatever makes you grin.
Even on my bone stock (well, K&N filter - woo-hoo) engine and Azenis, I still find very few situations where I could really do with a bunch more power. As opposed to a bunch more grip that is.
Don't waste another minute waiting on parts, or anything else. Just get out there and start racing! You will suck at first, and you will be slower than many other cars, but the only thing you will regret is not starting earlier...