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Old 11-17-2008, 07:41 PM
  #3309  
John St.Amant
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Sure on a buggy... but the fact of the matter is that the rebound on a road shock has little or no effect on the handeling of your car. A drag racing shock on a real car is usually a 90/10 rated shock . If you havnt noticed, rebound only happens when you extend the shock all the way out and compressit all the way in. Then and only then the preasure difference above the piston makes the shaft return. Now either you have too much rebound... meaning there is more oil in there than needed and that would cause a leaky oring or even wirse a blown out shock. In some circumstances if there is a bladder involved and the bladder is allowed to compress air above it , it merely gives a place to relieve excess preasure and not allow pack. If you hadnt realized that once your shock is on the car , the piston is about half way down and is limited by the droop screw and the mechanical limit of the car itself. Shock absorbers for real cars have these settings and are far more complicated than what we use them for. They simply dampen the effect of the spring so it doesnt bounce like a car that needs new struts. Rebound my effect your buggy where the arms are allowed to droop to the full extent of the travel of the shock. Try this.. build your shock with 50 % rebound and let it sit in the middle of its travel for a min with no spring. Then compress it to 75% and see for yourself how far the shock returns. Not much ! We Dont have nitrogen gas cartridges and pre programmed mechanical valving.. Just a puck with holes in it and oil. The oil controlles the damping and the spring controlls the rate of return. Stiffer springs usually require thicker oil and visa versa. Put a heavy spring over light oil and the car bounces. Do the opposite and the oil doesnt allow the spring keep the tires on the ground. A 90/10 shock has almost nothing for the down stroke but dampens heavily after hard acceleration (if your car can pull up the front end) so the car doesnt slam the ground and kill your e.t. from dragging the K frame at the 60 ft mark. Our shocks are not that involved. Rebound is to make 2 or 4 equal shocks that wont blow out. I have spent alot of time playing with shocks,,,, maybe too much. Bladders and droop screws on touring cars make things like pack obsolete and obscure. over fill and blow out .. underfill and suck bubbles. thats all!
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