I've been messing about with sweep picking since january , i still can't nail it. like teh part in the intro solo of 'one' (metallica) i can play it but its not fast enough. Also children of bodom and ynwi sweeps give me trouble as well. Problem is that I can play arpeggios but they don't sound fast enough.
the ones i've beenm practicing with are

Basic (1) (2) From 'one'
-1-------1-|-
--2-----2--|-
---3---3---|-
----4-4----|-
-----------|-
-----------|-

---14----19------14----------------------15 14----
15---------------------------15---------------------15--
-------------------------------------16-------------------14


Paul gilbert style string skipping
-8-7-8--5-----12-10-12-10---------|---------9-5----------
-----------6-------------------9---|---------------7--5-
-------------5---------------------8--|-8-5---------------
----------------------------------|---------------------7--5


Children of bodom (don't worry an easy one) These three are done quick @ 230bpm so it should take 2-4 seconds to play this. It takes me 8
T
-17----20----19-15--24-19-15---------------
---16----17-----------------------17------------
-----17----16------------------------16---------
-----------------------------------------17P14--
-------------------------------------------------17
------------------------------------------------

these are some easy ones but i can't nail the speed.
I can include another 8 by Yngwi but the post would b 2 long. how can i improve my speed.