Originally posted by Aggdaddy
If you're using 20% nitro and the Rossi Pixi Black 3 port straight out of the box (no modifications) The engine will not top out. You won't hear it scream down the straight-away like you're supposed to when it is properly tuned.
If you use 30% maybe. But I use 20% and I removed the shim, installed the turbo head that came with the engine, and installed a NovaRossi ultra cold turbo plug.
I just had a race last night. My temps were around 245 and under after a 5 minute heat. It moves like it should. I'm running with X12's and novarossi 3 ports.
Again, this engine is not the easiest to tune, so have patience and have fun.
For you guys running the Rossi engines, I would suggest you carefully read the following thread about engine shiming.
http://www.rctech.net/forum/showthre...g&pagenumber=1
I think in page 2 or 3 there is an explanation concerning this particular engine, done by Dennis Ritchey (Motorman).
But read all the thread, it's the best 101 on haed shiming i've found.
AFM