Ahhhh....we can call it the "X FACTOR".....

grampi.....you'll need parts to handle the "X FACTOR".

As for tuning the suspension....there are books on this subject and others who I would say are more qualified than I am to give you first hand experience....different setups....springs....oil weight....etc. But...I did remember this link that you might be interested in. While your there...perhaps when you have more time...you can check out the RC Articles section. Lots of good stuff there.

http://www.rcnitro.com/rn/articles/tune_sus.asp