Ok guys My 450r has an Lrd Exhuast and is jetted. I darg race a lot and need more speed. Can anyone reccomend some things to help me out thanks.

 

HRC cam. It primarily gives you top end. I presume you opened up the airbox???

 

Do you want more speed; ie. top end speed, or do you want to be quicker?
You can do all the engine mods you want and it won't make your quad faster, it will however make it quicker.
The only way to get a faster top end is to change the gearing, tire size or an after market rev box.
No matter what engine mods you do, the engine will only reach a certain preset rpm with the stock rev box.