This is the first "installment" of a series of tech articles that directly relate to you and your suspension design. These will be more informative and allow everyone on the site to gain knowledge in general suspension tuning. Alot of this information is quoted or taken from numerous people.
Our Mac-Strut front suspension, free-travel is the distance from the bottom of the bump stop to the top of the strut bearing (or camber plate). Most of use lowering springs to lower our cars. Its the easiest thing to use...There are pros and cons to this, but we will go over that in a later article
There are other ways to gain travel such as relocating the hub and spindles higher, Speed tourning cars do this, but I don't think there are too many on this site that will be doing this so we will discuss other options.
What are the disadvantages of lowering a car by shortening the springs?
The primary disadvantage of using shorter springs to lower a car is that the suspension travel is reduced.
This Stolen picture
Shows what exactly happens when you lower your car on springs...Obviously this is a basic drawing, but works EXCELLENT for our purposes...The blue circle shows the suspension travel loss when you lower your car.
WHY? Well you reducing the distance between the upper mounting point and top of the Shock or damper. This is forcing the bump stop to be lower to the top of the shock, which in turn reduces travel between the two corelating points, Bump stop and top of the strut housing. The only way around this is to either use a shortened strut housing or to cut the bump stop. There is only one company I know of using shorter struts for our cars
The other alternative is to cut the bump stops..Cutting the bump stops may seem like a bad idea at first, and it really isn't an ideal situation if you are able to maintain the suspension travel through shortend shocks or relocated hubs. The stiffer the spring the less travel is needed since the suspension doesn't compress as much, but alot of our standard lowering springs are only SLIGHTLY higher rate, requiring a trim of the stop. The bump stop is a shock limiter/cushioner, if you have the time and ability you could determine the ideal bumps stop length and spring rate. Too long a bump stop and you add a stop to the travel causing you to ride on the stops and not the springs...Too short a bump stop and when you do fully compress the suspension it will make the change in your ashtray rattle
Matching bumpstops to ride height is a key thing to do, this is done with testing an knowledge...Or just get shorter dampers
Comments? Questions? Concerns?
More too come
