Rocket Blue violent bouncing back and forth

**PushinTheLimit** · 10-09-2013, 07:30 PM

Originally Posted by 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.

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** · 10-10-2013, 09:10 AM

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** · 10-10-2013, 09:56 AM

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** · 10-10-2013, 10:52 AM

**PushinTheLimit** · 10-10-2013, 10:54 AM

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** · 10-10-2013, 10:58 AM

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

**PushinTheLimit** · 10-10-2013, 01:36 PM

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** · 10-10-2013, 05:09 PM

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** · 10-10-2013, 09:25 PM

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

**TALON75** · 10-11-2013, 03:06 AM

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.

**PushinTheLimit** · 10-11-2013, 08:21 AM

Originally Posted by 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

For that 14 1/4", is that tip to tip, or is that center hole to center hole? If it's tip to tip, it's right on 14 1/4"... if it's center to center, it's 13 3/4". Also, my J-bar is sitting in the bottom hole on the right side of the rear end.

I didn't get to measure anything else last night as we were working on some starter issues. Thanks for all the help so far everyone... it's been very informative for me.

**7uptruckracer** · 10-11-2013, 09:01 AM

The stabilizer measurement is center to center any heim or tube measurements will be center to center so 14 1/4 could be your problem there if you lengthen it it will push it farther away . And by j bar measurement he means lateral location of the rear end which you measure from your upright 90/10 bracket to your RR inside frame rail your 90-10 bracket bolts to the top of your rear end it's the pair of somewhat triangular ears on the top measure from the outside of the right bracket to inside of RR frame rail but I suspect you might have found it with the stabilizer arm on the lift bar

**PushinTheLimit** · 10-11-2013, 09:33 AM

Thanks so much... then yeah, but lift bar is 1/2" to 3/4" too far to the right. I'll adjust it to 14 1/4" and that should adjust the rear end back to the right instead of so far left. I had a couple of guys comment on my last race that the rear was tucked in really far left in the car.

**Lizardracing** · 10-11-2013, 09:33 AM

It's a good idea to wrap the chain with tape to keep the links from getting tangle up. I like the chain used on swing sets that's has the plasitized rubber coating. It's cheap enough and easy to work on too because it doesn't leach glue that duct tape can after repeated heat cycles and car washes.

**7uptruckracer** · 10-11-2013, 09:43 AM

You tucking the LR is a product of your bar angles and with the fact you were on slick track shock settings you were probably hiking really far with no limiting chain. So don't worry about that get your Lateral Location Checked. Get your Lift Arm Stabilizer arm the right setting. Even back out your shock settings to suit your track conditions and set your chain and you should notice a big difference in drivability. Really Really make it a point to call Rocket tell them you'd like a Setup Book for your Chassis and they will mail it to you! We don't mind giving you this info but its all in there!

**PushinTheLimit** · 10-11-2013, 09:44 AM

Thanks Lizardracing, I've had a couple of guys mention that about the chain. I'll make sure and take care of that too.

**PushinTheLimit** · 10-11-2013, 10:41 AM

Originally Posted by 7uptruckracer

You tucking the LR is a product of your bar angles and with the fact you were on slick track shock settings you were probably hiking really far with no limiting chain. So don't worry about that get your Lateral Location Checked. Get your Lift Arm Stabilizer arm the right setting. Even back out your shock settings to suit your track conditions and set your chain and you should notice a big difference in drivability. Really Really make it a point to call Rocket tell them you'd like a Setup Book for your Chassis and they will mail it to you! We don't mind giving you this info but its all in there!

Yes, thank you for all your suggestions. I called Rocket a couple days ago and they are sending me a book, so it should arrive any day. Probably not in time for my race this weekend, but I got on off weekend after this one... so I should have some time to sit down and read through it and get familiar with the setup. The track I'm going to this weekend will be starting tacky, but slick off most likely by feature time and is much larger than I race on last weekend.

I'll update this thread on Sunday how the car performed and see how all the changes did for it. Thanks again everyone... you've been a huge help.