Head

[Maitre_Te_Te]

I know polish intake on old head with carburator is not a god idea because the carburator is not the best for to do a good air/essence mixture. This is for this the turbulance are good for th do a good mixture. But now, tje injector is directly on the intake valve an do a good spray, then polish do a good flow for best mixture intake in cylinder. But it's sure to porting intake for to do a bigger porting this is not good on N/A beacause you reduce the mixture speed/flow. (like a presure produce with the same water flow in different pipe)

This is not just matematical because if you see a dyno sheet, the hp on yaris is at her top at 5600 rpm and after, hp go down. If I unlock the rev limit, thne engine in matematical can go at 8000 rpm but in reality with physic, the engine can't. Honda can go at 8000 RPM because her engine have maybe 13:1 compression and her disign is the best for high RPM. Yaris it's design for the torque, not hp at 8000rpm. What I think, with a best compresion, I will go search more HP at more rev (maybe 6200) at the top of HP at rev limiter.

Sorry again for my english! this is hard to explain.