Guy builds his own Track Day car with custom suspension
One of my favorite things about YouTube is the build videos, where you can watch as a YouTuber creates a car little by little, one video at a time. I was browsing the YouTube archives when I came across SK8215, who has been slowly turning an E55 AMG road car into a "properly fast track car".
In part three of the build, the guys remove the standard air suspension for a set of coilers on the front. Fitting coilovers don't necessarily improve lap times, but they are infinitely more adjustable than air suspension. You can also simplify and lighten the car by removing air valves and the onboard compressor. Coil over shocks allow for quick adjustment of ride height (as does air) but also pre-load and damping rate. Some coilover shocks, like the Fortune Auto 500 series have adjustable camber settings too.
This video maker bought shocks that don't have that adjustment, so he did a very simple and clever mod to his control arm, elongating the mounting holes to allow him to change the cars camber up to -3.3 degrees of negative camber. The suspension stuff is covered at 7:05. Prior to that, he shows how he made a custom carbon fiber duct for brake cooling!
Then, the real fun starts. Realising that the E55 rear control arm set-up doesn't have enough room for the coilovers he bought, the video maker creates his own pushrod suspension system!
The user starts by calculating spring rates and dimensions.
Then, he produces some sketches and drawings to work out the configuration and mock up his design.
Afterward, he checks the layout and tweaks it slightly using CAD modeling software, 3DS Max. The set-up even has a cantilevered roll bar built in.
The guy then welds up the components out of box section steel, adding captive nuts and lobes for mounting all the suspension too. He even makes his own pushrods. The whole set-up uses rose or Heim joints for a super smooth and controlled action. The E55 owner also built in an adjustment in the positioning of the spring and roll bar mounts.
The finished result is a very compact set-up, with dampers running down either side of the suspension mounts. This is the first prototype, so he is suffering from some spring bend, but that can be fixed by adding more joints that allow for additional movement. Still, the design is impressive and he claims that his lap times have dropped by up to 2 seconds after installing his pushrod suspension. Amazingly, the owner only had to modify a few square inches of the wheel well and he made the whole lot to be removable if needed.
After fitting the push rod system and dropping 2 seconds per lap, the car now leans more towards oversteering, so he plans to soften the rear shocks a bit, but overall, the suspension performance has been transformed. Not bad for maybe a couple of hundred bucks worth of steel stock.
This video shows the pushrod set-up in operation. The welds might not be great but it's ingenious and very cost effective. If you didn't feel up to the fabrication, a machine shop or engineering place would be able to knock one up based on drawings you provide. Check out the user's other videos here, there are loads of this build, including making and fitting a front splitter and a DRS wing!