View Full Version : Rocket Chassis Black Front End Setup.

07-26-2010, 11:33 PM
Im Still Having Trouble With My Rocket. Its Good Early In The Night And Early Heat Races But When It Slicks Off It Turns To Junk. It Has No Side Bite And No Drive Off The Corners. 650 Lf 300 Rf 133 Stack Lr And 225 Rr Even Had A 250 Rr. 275 On The 5th Coil 2nd Hole From The Back, And A 4oo On The 6th Coil. I Have Ohlins Shocks Set On Slick Track Setup. I Start The J Bar At 8 1/4 And I Take It Up As High As 9/3/4 And It Will Not Plant The Rr Tire At All. Even Tried The Straight Bar As Well???? Im Out Of Ideas Of Things To Try??? Please Help

07-27-2010, 12:50 AM
check your ballspine...sounds like it is jammed up..will cause the car to do all that you have listed

07-27-2010, 08:04 AM
If its that slick move the J bar up to 9.75" and put a 300lb spring on the RR.

Make sure your bars on the RR are all the way down, both, to take the drive and indexing out with the 300lb spring.

Also, you may try a 350 RF, the black front ends IMHO like a bit stiffer spring, if your not on a bump stop. Otherwise you lack fwd bite with a light spring. Blue fronts are different.

One last idea, some guys like the LR shortener bracket for the LR top rod, some guys dont. give it a try. It helps get the car up on the bars faster and easier, plus it tightens the car up faster. As with anything thou there is a trade off, you will loose grip on the big end of the straights usually, grip wont last as long.

Just some ideas.

07-27-2010, 08:06 AM
check your ballspine...sounds like it is jammed up..will cause the car to do all that you have listed

What he said, and make sure you have enough droop travel on the LR. 13.5" to 13.75" from the frame rail, down to the axle tube.

07-27-2010, 08:17 AM
Is this car up on the bars or flat, and does it change from up to flat ,as the track loses grip.

07-27-2010, 10:17 AM
That's way too much adjustment throughout the night on the j-bar. going up an inch and a half is altering what you have going on to an extreme. Try getting the car tighter for early, so you aren't taking such a big swing at it for the feature when it slicks off.

Agreed though with above posters it sounds like something is bound up to me if it's that bad.

07-27-2010, 11:39 AM
i only have about 12 inchs of lr drop right now??? i have room to add more. the car does get on the bars.

07-27-2010, 11:49 AM
What is currently limiting your travel?

07-27-2010, 12:44 PM
went through the same deal on a 07 black front rocket... the car was to the extreme on everything to find drive and side bite...checked the ballspine(it was jammed up) and the car was trying to leave the track like a rocket it was so tight..only thing u could see from the drivers seat was blue sky and stars

07-27-2010, 12:59 PM
right now the dummy shocks is limiting the travel. it dont have an extension on it and its in the bottom holes on the bridcage??? i think if i get more travel back in it it has to help with some of my problems... and my drive shaft we are running a reg brinn trans and a 35 1/2 inch drive shaft

07-27-2010, 01:05 PM
you need to have at least 13.25 of drop on the lf rear... the slicker it is the more you can throw at it, agree with an earlier post about the 300 spring..awful light for a black front car, not saying it is wrong

07-27-2010, 01:56 PM
i had a 400 then went to 350 then to 300 and honestly i really cant say that it helped much at all might be because of the l/r travel thanks every one for the helpful ideas and theings to try i really appreaite then help jp

07-27-2010, 02:57 PM
If You Move The R Bars Down Why Would You Go To A Stiffer Spring? Just A ?

07-27-2010, 04:12 PM
Fix the droop before you do anything else. 12 inches isn't even close to where it needs to be. The extra 1.5 inches adds up to alot of dynamic wedge, which will tighten you off the corner. I almost guarantee this is the biggest issue with your car. Good luck..

07-27-2010, 08:54 PM
had a car with 12 1/8" of drop that wouldnt stick for nothing went to 14" of drop last week and the car stuck and was about a second faster

07-27-2010, 09:19 PM
Dummy shock bracket should be in top birdcage holes closest to axle tube, then flip the bracket so the shock bolt is also closest to axle tube.You can also move the dummy shock bracket to the drive shaft side of the birdcage to give you a little more. Pay close attention to the birdcage to ensure it doesn't "cam-over", then you have gone too far :eek: One more thing, bar locations can limit the drop. Good luck.

07-29-2010, 04:50 PM
ok well we fixed the drop problem we have about 14 inch of travel now. we where also thinkin about changing from running the short lr bottom rod to the long lr bottom rod??? what would this do???

07-29-2010, 08:28 PM
A 600 spring on the lf will make the car way to lose on exit I would soften it to at lest a550 you can add more compression to the shock to stiffen the lf and it won't kill the car getting off the corner

07-29-2010, 08:34 PM
your left front spring aint goin to change the car a much at all from center off. most of the weight will probably be off that corner on exit.

07-29-2010, 08:42 PM
We have run the black frount rocket for a while it dose just as he said works great as long as there's mositer in the track but as soon as it starts to dry out it's way to lose if the lf is to stiff it transfers to much waight to the rr lossing up the car on exit you can change e ery thing else on the car but if it's transfering to much waight to the rr it will allways be hard to tighten up

07-29-2010, 10:07 PM
i have a 275 on 5th coil now if i go up does that help forward traction and how high should u go befor it hurts u

08-01-2010, 05:16 PM
put u a 400 in u will be find
i would not go above a 450

500 left front
400 right front win the track gets dry slick u can go to a 375
225 left rear
200 right rear
put the fifth coile in the last hole at the back
raise the right rear botton hole up one hole win it is dry slick

09-11-2014, 01:48 PM
What would your recommendations be for valving on all the shocks?

09-12-2014, 12:16 AM
getting the 14 inches drop is major. dropping the lf spring is major took a lot of convincing from a friend on here to drop mine and to find that extra inch of drop but itl lite a fire. to get 14 nch drop you may have to do some finagling. check and double check that your axle tube isn gonna hit your shock. you don't want a bent shock in the first 5 laps of your new setup. I had to fab sme spacers and extension for my left rear front shock to get it right so don't be surprised if your axle hits it just depends on your bird cages and bar placement. I will say this if your in the top hole top rod and bottom hole bottom rod your gonna have issues if your in center index on birdcage. check and make sure you don't need a purpose bent bottom l/s 4 bar rod. depending on your rod locations you might. don't wanna break that on the first lap either. seen it happen every year.

10-14-2014, 10:17 PM
why dont you take that 133 off the LR?

save the racers
10-15-2014, 11:19 AM
Brought back to life from 2010 hope he has his issues worked out by now