One Barnett clutch spring (to replace one of the stock springs) are good for at least 150 rwhp, two Barnett springs will cope with 250 hp. If you clutch are worn, but not worn out, you can fix it temporarily by adding another thin steel plate. If your steel plates gets warped, don't try to fix them, get new ones. If you have ever used synthetic motor oil in your bike and the clutch starts to slip, replace the oil with a good mineral oil such as Castrol GTX 20W-50 or similar. To cure your slipping clutch you can sandpaper the fiber plates which removes the hard black residue. Clean the fiber plates thoroughly to remove any grinding material/debri.
When you reassemble the clutch basket, make SURE that the clutch basket gears are lined up with BOTH the generator AND crankshaft gears. You'll bust one or all sprockets if you're not careful when you torque the clutch hub nut.
I'm currently using the gsxr1100 diaphragm spring clutch in both bikes with two Barnett springs and when it's a bit worn I just add another stock spring or an extra steel or add one thin spring spacer. The Bandit can use the 90 gixxer clutch by replacing everything except the backing alternator/oil pump sprocket since the gixxer and Bandit don't have the same oil pump gears. I'm also using the WUSS diaphragm lockup clutch which is a must with more than 250 hp. I also got the BDE 4-spring lockup but hardly use it as the clutch lever feel aint what I like or are used to. Never ever buy anything else than the Suzuki OEM clutch plates. Vesrah and Barnett might seem to be a cheap and good choice as a replacement but they're too grabby for dragracing a no-bar bike.
ZIP file containg Brock Davidson's BDE clutch cushion kit (updated 2011-06-20)