What is vibration/shudder at 9000rpm??

[Ya Mahn]

I'll get this thing dialed in yet! I have a vibration at about 9200-9500rpm which translates into about a quarter-half throttle roll on? It feels like the track is ratcheting but a lot less intense. The track is tight, the primary supercharger pulley is within spec and the secondary pully is also in spec. It kinda feels like a shudder. Any ideas?

 

[obr]

Installed new drivers?

 

[Ya Mahn]

New track drivers? No there are less than 2000 miles on it but its a thought. I'll check them out

 

[4strokes are better than2]

probly stock driver they dont last long under boost

 

[woodsrider]

Check the bearings on your jack shaft and drive shaft.

 

[Ya Mahn]

Thank you for all the suggestions, I found out it was the primary belt on the supercharger was a bit loose causing it to skip at 9000rpm.