Spring height question for billet or Rocket Bonehead

[Rocket_Racer]

I have a black front end Rocket and due to my shock having a reservoir at the top (rules mandate not external canisters) I have to use a 8 inch spring to get the car down to ride height. What is the best solution to this problem. I know I'm not supposed to have a shorter spring on the left front, but I'm not sure how to remedy the situation. I would put a 8 inch spring on the right front but I'm sure that would coil bind. Should I move the shock mount on the frame...use a drop lower on the LF...or not worry about having a 8 inch spring on the LF and a 10 inch spring on the RF.

[MasterSbilt_Racer]

I am neither one of those gentlemen, but it doesn't matter.

[JB151]

I know I was not the person you asked, but I had this same problem on a set of C2P shocks. I had PPM make me a lower with a 1" drop in the shock mount. It fixed the problem and I was able to run a 10" spring.

[billetbirdcage]

Contrary to popular belief spring hieght has no effect on the performance of the car as long as it is on a slider or coilover. The pivot point of the slider or coilover is the important part. So with that being said a 2" spring will perform the same as a 14" spring (if the rates are truely the same and side deflection of the springs are the same - latter most likely not true) but you have to deal with coil bind. Use the shortest spring you can without binding the coil (leaving some safety room) as this will allow for less wieght with the spring.

Do not move the upper mount! You would be changing the place the spring is pushing on the frame and vice versa, however this could benefit or hurt the car but it can change the car.

No problems with different length springs on any corner of the car. You can use a 10" on the RF and the 8" on the LF, but you may get into coil bind with either corner depending on rate and roll of the car. So you may need to use those lengths but use a extended travel spring like the Swifts or the Integra MX springs (maybe others also - less coils per inch which allows more travel before coil bind) or you will need to use a dropped lower mount lower control arm. You can look at this thread for dropped lowers as it will lower the shock mount 3/4" http://dirtracingforum.com/showthread.php?t=2045


I'm surprised you are having that much trouble, but i don't work on a rocket every day and never owned one. I know some GRT's with top reservoir shocks (like integra) are borderline on getting the LF corner down to ride height with a 10" spring as the nut just won't go up far enough with the reservoir.

[Rocket Bonehead]

I would agree with Billet. You should have no issue using an 8" spring on the LF. On the RF you should be using a 12" spring, but I gather you might be running into the same issue there.


My next question would be, are you sure you are using the proper ride heights and checking in the proper location? What year of car? I've set up everything from a '97 to a 2007 and used the same ride heights (with the RR dependent upon the style of birdcage) and NEVER had that issue. I've worked with every major shock brand with the exception of Penske's.

LF- 3 7/8" (4" is ok)
RF- 3 5/8" (3 7/8" is ok)


The only thing I can think of that might be wrong, provided that you are doing everything correct (which I will assume), is that the car had a new rack member installed incorrectly (putting the mounting point of the lowers lower than standard) OR it has been wrecked and the rack member tweaked.

Something to think about there.



I would use the 8" spring before I put a dropped lower on the car. In any case, I think there is most definitely an issue that is causing that and needs to be resolved.


RB

[Rocket Bonehead]

After thinking about it some more, are you sure that you have the proper length lowers on the car? If you have too short of a lower, then you would need to unwind the nut farther in order to get the ride height down because it would be standing the spring up closer to vertical.

LF- 15 1/8"
RF- 19 1/8"



RB

[Rocket_Racer]

Rocket Bonehead...I sent you a PM with some more info...thanks

[IDOXLR8]

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[IDOXLR8]

Ignore the above reply,just re read the title!:shock: