2006-Present Suspension/Wheels/Tires Recap

The suspension design can be by far the most involved and hardest part of the locost build.  Suspension geometry design in itself is multiple courses in engineering college that requires quite a bit of theory and math to fully understand.  If my locost were going to be used at the track or for auto-x then I would probably need to do much more research on design than I am going to do.  Since my car is going to be used for weekend romping and the local car shows, I’m more concerned with reliability and strength than high speed stability, cornering, and anti-dive geometry.  Sure those things matter, but I’m not going to lose sleep thinking about ways to get a couple more millimeters of adjustment out of my setup.  When I first started to research suspension design there wasn’t much out there.  People usually picked a width they wanted, chose a ride height, and built the suspension to match that.  The racing fellows would get fancy with computer aided design programs to get everything perfect.  These days I have found a few companies that actually offer the a-arms, brackets, and everything needed to make the most challenging part of the build very easy.  One of them is Kinetic Vehicles.  They offer an a-arm kit that comes with everything:

In all honesty, instead of researching for weeks and trying to figure it all out on your own I would just (and I am most likely going to) order this kit from Kinetic.  All that is left to do is weld on the brackets and adjust for the needed lengths.  Much better than ordering all the fittings and trying to do it by hand.  Also, I don’t trust my welds enough to do them on the a-arms.  That’s totally different than chassis welds. 

For the rear suspension I will just use a four link system with a panard bar.  Here is what a 4-link with panhard bar looks like:

I made the brackets for the rear axle and I have the heim joints for use with the trailing arms.  Next up is to make the brackets for the chassis and purchase some trailing arms.  As for coilovers, I purchased some motorcycle shocks a year ago and was going to use a pushrod system to make them work.  I only have about 90 dollars invested in the shocks and I think I am going to abandon that idea and just get some custom made shocks that will definitely work with my setup.  No need to spend 1000’s of work hours and 1000’s of dollars on a build only to skimp on the ride quality.  Here is a picture of the R6 shocks that I was going to use:

A good set of coilovers that are made for the locost setup will probably run about 225 dollars a coilover.  Suspension is the number one cost on the locost, even though most think it is the engine and driveline.  The next step in the suspension process is deciding on a wheel and tire size and then ordering an a-arm kit.  This section will most likely be the first I start working on in the spring.

~ by subyman on March 18, 2008.