Springs are a cheap thing to get for your R/C car at about $2.50 per paire and they will change the way your car jumps, turns, and tracks. I am new at R/C cars so I bought a few of springs to test on my buggy. I tested them all with 30 WT shock fluid. Here is the springs and how they worked.
This is a yellow rear, 2.0 rate spring. Most buggy springs are 2.5 inches this is a bit larger.
This spring seems a bit soft but works well with a high ride height. On the jumps it bottemed out with a level ride height. It has very good traction.
This is a pink 2.5 inch 2.4 rate spring. This is the spring that comes with the team losi xxx kinwald edition. The spring works ok with a leval ride height. It handles jumps well. If you hit a curb the buggy will flip over. It might work better with a 25 WT fluid.
This is a 2.5 inch 2.6 rate spring. This is my favorite spring to use. With a leval ride height it works good on jumps, turns, and 180's. You can hit speed bumps and curbs and not flip over.