Shock absorber velocities in off road
#1
Tech Rookie
Thread Starter
Shock absorber velocities in off road
Has anyone ever looked at shock absorber velocities in off road conditions on a XXX-T chassis? My question stems from a night of playing with the Losi shock matching tool. I see some differences at very low speed compression and rebound, but as I move toward medium speed (estimated by the speed of my hand compressing or rebounding the shock tool) the shocks even out. At high speed the difference is starting to return. That got me thinking about shock velocities in real world applications.
Thanks,
Ron
Thanks,
Ron
#2
Tech Addict
iTrader: (4)
Try running the same test again without any oil in the shocks-it could be that the drag of the o-rings on the shafts are a bit different from uneven wear of the o-rings or the shafts.Another thing to check is the drag of the piston in the shock body.Run your fingernail around the outside of each piston to check for any residual flashing where the piston was attached to the "tree" during molding.Sometimes the pistons need to be very lightly sanded on the outside to get them just right.The Losi shock matcher is a great tool but it can cause you to waste an awful lot of time on shocks if you are a little too "detail oriented"(like me)
#3
Make sure to use some AE Green Slime when building your shocks. It really helps even them out. I also dry run my shocks, first without and then with springs, on the Losi tool before filling and it usually points up any compression/rebound bias issues. This eleminates any guesswork when it comes IDing problem areas. If they are not the same after filling it can only be oil volume if you evened them out dry. I learned way early on the importance of good shock building and the Losi tool just makes it easier and more accurate.
#4
dont just look at the absorber only because smooth suspension depend on all moving part that connect with it... its also better to lube with grease all the moving part esspecially all the hinge pin and inside the plastic arm hinge pin hole itself. dremel the very tight part (lower arm) to make it moving smooth. sometime the hinge pin get rust and will affect the arm movement
#5
It is important to make sure all your suspension work smooth and move with no binding, but IMHO greasing the pivot points on an offroad car is inviting disaster. Once all 4 corners will drop from full up to full down under their own weight with no shocks or swaybars attached, hook everything up and give your car a light bath of WD40 or some other kind of silicone free spray lube. I use the All-Mart house brand as it does the job and costs less than a buck a can. Once you've sprayed the whole car (less body shell of course) down with lube, let it dry completely before you put it in the dirt. I usually do this the night before a race to insure all the liquid in the spray has ample time to completley evaporate. This helps your moving parts, reduces the chance of rust on steel parts, and also makes for a much easier cleanup after the race.
#6
Originally Posted by fhm101
greasing the pivot points on an offroad car is inviting disaster.