my t maxx 3.3 has the resonator pipe. i noticed the nitro 4-tec with the 3.3 has a blue resonator pipe. heres what traxxas says about the pipe i got-

the Resonator dual-chamber Maxx pipeprovides an average peak torque increase of 16% over the standard Maxx pipe, and a 10% increase in total power across the whole range. Full mirror polish adds that final touch.

and the Resonator™ Blue-Anodized Aluminum Tuned Pipe
The Traxxas Resonator aluminum tuned pipe is precision-engineered to maximize power output from the TRX 3.3 Racing Engine. The silicone stinger cover provides extra safety. Improved top-end power, enhanced bottom-end punch and smooth, linear power are the combined result of the laser-etched Resonator tuned pipe and the extreme horsepower of the TRX 3.3 Racing Engine.

i dont want it just because its blue,lol. if its equal to mine then i wouldnt get it. but if its better than the one i got, maybe i would upgrade it.