Rocket Blue violent bouncing back and forth

[PushinTheLimit]

I have a Rocket Blue. PPM had two different chain kits, one that went around the bearing, and the other around the axle. I ordered the one that just went around the axle for now. Any measurements would be very helpful... thanks everyone!

By the way, pardon my ignorance, but what is underslug? That's a new term to me.

[fastford]

I have a Rocket Blue. PPM had two different chain kits, one that went around the bearing, and the other around the axle. I ordered the one that just went around the axle for now. Any measurement would be very helpful... thanks everyone!

By the way, pardon my ignorance, but what is underslug? That's a new term to me.

underslung means you have a frame rail/ tube running front to back under your axle tube, ive never run a limiter chain on an under slung chassis, i make sure that with the lf rear at full drop and the right side jacked up, the left shock is not bottoming out, essentially your using the frame as a limiter. a chassis that is not underslung has nothing below the axle and you really need a chain or you could destroy a shock . also on my underslung chassis i wrap a piece of roll bar padding around the lower rail to help cushion the impact. also i saw where some one is making a thing like a spring rubber to put there, been meaning to check on one, good luck

[PushinTheLimit]

Ok, now I understand. This car isn't an underslung chassis. I also called Rocket Chassis and have them send me their setup book. Hopefully we can get my car ready for this Saturday and I will update this thread with the changes I made and how it worked.

[Len72P]

If your shocks are built for slick tracks and adjusted slick , you probably have very little rebound on the left front and left rear. Even if you go to the larger track , hot laps might produce same effect , maybe less violent. I would get ready to add rebound. Also your corner entrance can effect chassis badly. If you are letting it drop off the bars , then turning , them nailing the fuel , wuppy , hang on. Ensure you are entering on the fuel and brakes before getting off fuel. You must be on the fuel or the brakes and turning at same time or you will drop off the bars. Also tighten up compression on left rear behind to help keeping it on the bars.

[grt74]

there sounds like there could be a couple of things going on,ill bet that if you put the car on jack stands and put a jack under the rr and raise it like the car is in the corner the lr birdcage is over indexing(just 1 thing that came to mind)also like some of the other guys have said it will kill your lr shocks over time,so that being said i would never run the car without a chain limiter and it is a very useful tool,now once you put a chain on it,if the car looses forward drive youll have to find it somewhere else,i would work there 1st if the car is good at your home track

[PushinTheLimit]

If your shocks are built for slick tracks and adjusted slick , you probably have very little rebound on the left front and left rear. Even if you go to the larger track , hot laps might produce same effect , maybe less violent. I would get ready to add rebound. Also your corner entrance can effect chassis badly. If you are letting it drop off the bars , then turning , them nailing the fuel , wuppy , hang on. Ensure you are entering on the fuel and brakes before getting off fuel. You must be on the fuel or the brakes and turning at same time or you will drop off the bars. Also tighten up compression on left rear behind to help keeping it on the bars.

I think you just nailed it. After watching the video again, I was letting off the throttle before the turn, turning in, then I would brake before I got back to the throttle again. So that probably got it off the bars then I shocked the suspension so bad that I over extended the LR shock. Makes sense to me.

The track I'm going to this weekend is most likely going to start off a little tacky and then dry up and blow off to be somewhat dry. So I figured I would set the shocks about in the middle between a tacky and dry setup and then adjust from there for the heat and feature races.

[PushinTheLimit]

Something else I noticed when I was looking under my car last night, the lift bar (I think that's what it's called) is hitting one of my lower chassis bars. The very tip of it looks like it has been digging in and has slightly bent that chassis bar. I don't know if that was done in the past before I bought it, or if I did it racing the other night. When it's on jackstands, the end of the lift bar is right against that chassis bar... when I jack up the rear, it pulls away from that chassis bar, but not by much.

Is that normal for a Rocket? Looks to me that the front of the lift bar should move slightly left even an inch and that would solve the problem... or would it?

[7uptruckracer]

The lift bar comes off your rear end and is the long bar with a series of holes that your 5th and 6th arm mounts to and on the rocket it has a heimed tube that is about 11 1/4 inches long that connects to the right side of the lift arm and to a chassis mount the sets your side to side measurement on your lift bar. I'm not sure what bar it could contact it either will hit your driveshaft on the left side and I hope not your inner rail on the right side if that what your referring to if it is let us know and we will get you the measurement I think its 11 1/4 it could have broken something in the part and made it hit it maybe wrap the spot in tape to check for a rub this week. Let us know we will get you measurements

[PushinTheLimit]

[PushinTheLimit]

The first picture is with the rear sitting on jackstands and the second one is with a jack under the rear. It pulls away from that chassis bar a little, but it is nowhere near the driveshaft as you can see it in the background.

[powerslide]

At ride height is the lift arm straight w/ the bar above it that the 5th coil and 6th coil mount to?

[PushinTheLimit]

I'll check tonight when I get home... I'll also set the car down and take a picture of where the lift bar is and post it on here.

[7uptruckracer]

The helms that mount it could be screwed to far out or magnets not level check your pinion angle too! Your lift bar should be 36-44 inches and your stabilizer from that lift bar to chassis is 14 1/4. And your chassis drop on a non under slung is 12 7/8 to 13 1/8 from top of axle tube to bottom of rail with car elevated on the blue fronts

[let-r-eat]

What are the top and bottom bar lengths? Someone has messed with something.

[TALON75]

Check your jbar measurement also, the rearend may be too far to the left pointing the liftarm too far to the right. might just need to lengthen the stabilizer bar that is connected to the midpoint of the liftarm, either way it should not hit that tube at all.