i cant seem to get the truck to leave right.most of the time it feels fine but whenever i go over 10 lbs of boost the truck bounces violently and probaly is on the verge of breaking something if i dont let out. any ideas on how to stop this.Tires, clamps on springs.etc?

Launch with less boost or RPM, controlling axel wrap will limit the jumping if you do break traction though. Bars, springs, ect control it. Also doing things to keep from breaking traction will help. Air down tires ect. You running on the stock shocks? They suck. If your nose is raising fast and hrad you need to control that too.

What tire pressure are you using?

If a car hooks the tires 100% it will never hop. It's the slip and release that causes misbehavior.

If you haven't already, drop the PSI to about 30 on the fronts, and 40 on the rear.

Yeah Im Running Stock Shocks And I Think Im Getting To Anxoius When The Lights Drop. Im Gonna Try To Clamp The Springs And I Got To Get Some Different Tires. Ive Been Running The Buckshots And I Think There Killing My Time.

As the rear end of the truck lifts up because of all the torque being transferred to the rear axle, the shocks extend to their max extension. As the truck continues to raise, there's no more shock and the result is the bucking, or hopping.
Some companies offer shock extenders that are used in drag racing as well as wrapping a U-bolt around the springs, like you said.

Think about the torque getting applied to your rear end, tires are tring to turn one way so that makes the rear end wana do what?

Whats happening here is......You launch hard and the pinion wants to rotate up, your springs flex in an S type shape, you break a bit of traction and unload the tires and that stored energy in your spring unwinds itself, pinion goes down, you catch traction pinion goes up, violent cycle, bad for traction and bad for parts. Your leaf spring truck will tend to squat on launch, this is bad too in a 4x4. Weight comes off nose, front tires break traction, back tires break traction(starting the wheel hop) and bring on the bunny hop! Some cars have such hard anti squat that they can top out the shocks and when you do that it will break traction but this isnt whats happening to you.

If you dont break traction you wont hop! Not breaking traction is how you go fast.

Start small on boost and work your way up. Its better than starting big and breaking something.

For 285 tires, what should I run for air pressure? I seen the 30/40 psi mentioned by McRAT, didnt know if it would be different with bigger tires

I have been at 31 front 26 rear, running 305/70/16s but they are designed for rock crawling and have fairly strong sidewalls, when i was running higher pressures 60s were down, but they should be adjusted for track conditions

Yeah Im Running Stock Shocks And I Think Im Getting To Anxoius When The Lights Drop. Im Gonna Try To Clamp The Springs And I Got To Get Some Different Tires. Ive Been Running The Buckshots And I Think There Killing My Time.

The tires are hurting u since u only have half as much rubber on the road.

Get some fairly wore out BFG or other street tread to race w/.

I get the bouncing when I launch too. I'm running very worn out BFG M/T's with about 60 PSI. I know, I know too much air. Guess I'm gonna have to splurge and get a set of slicks.

try clamping the springs, i have heard that helps....

Caltrax makes some nice traction bars also.....:)

Ok......found a new bouncing at track. Rancho's set to the softest setting instead of hardest. Instead of a quick violent hopping I get a few feet out and the truck hops hard, sets down and does it again, hped about 3-4 times and made it past the 60'. Much slower than wheel hop from the axel wrap.

Controll weight transfer, controll axel wrap.

too much air in the tires can also lead to bouncing/hopping/shuddering on launch

I run 35-45psi in the front and 25-35psi in the rear with the 285 BFG AT's on 6.5" wide PYO rims. Wider rims with the same tires may require more air pressure.

Atleast clamp the springs.
I am running Cal Trac bars and have no wheel hop anymore.

I think "wheel hoping" will eventually break something.

do you have your torsion bars raised? That will make the front hope

Its it in 2 or 4wd? and if you 4 do the front tires squeal?

Where would a person find caltrax traction bars??

I think alot of it is in the tire pressures .The 4 times we went to the track we never had any bad hopping and we left hard.Caltracs can be found on trippins web page or mike L's.We didnt have the stock shocks i think they were rancho's.NLDP

Its clicky in my sig for Trippin or call Mike L at 310 674 4400