well, if you have youre mind set on buying the nova a ofna 053 pipe might give it a small increase in mid power you probally wont be dissapointed. if I was competing I would want every advatage I could get and theclocked works .21 5b is faster than the nova.I didnt know really to much about .21 sised engines until I read this thread. and I wanted to thank supertib for the pro advise.