Ok so for the past few days I have been going back and forth in my mind on what to do swap my motor or build up the D15 everyone said swap it was very clear. But I think I am going to just build the D15 and put nitrous on it. I mean I dont plan to make a super fast 1/4 mile car I just want to race some friends. So I am asking is there any good upgrades for the D15 Like for Ex. Throttle body or Head or anything thats not obvious like exhaust and intake? Thanks alot.