Does changing valves give any performance upgrade ?

lets say if any of those would fit:

RACEMASTER VALVES
http://www.manleyperformance.com/honda-valves.html




sorry if its a stupid question , I dont know anything about this stuff.

 

On other brands maybe, but not on a Honda/Acura. Honda/Acura does a lot of research on their heads. It there was performance to be had by changing valves I'm confident they would have found it. Honda/Acura already uses multi valve, forged alloy construction, VTEC, etc.

 

The short answer is no.

The only thing that will give more horsepower is changing the volumetric effiency of the motor. Valves alone won't do that. Changing the SIZE of the valve opening, porting & polishing the head and intake, new cam (you've already got VTEC) will. Now you're talking major bucks for machine work and engine work. Also kiss your warranty goodbye.

I think you may be mistaking pure racing mods for something that's easy to do for the street. Racing valves are designed to handle sustained high RPMs and very high heat, things you are VERY unlikely to encounter in street driving.

If you want to mod the car, there are lots of other ways to see performance increases at much lower cost, both in terms of $$$ and reliability.