F55 is the designation of an option that GM offers on Corvettes. That option is part of the suspension of the vehicle. By operating a switch to the "sport" setting, (I believe) electromagnets are activated to tighten up the suspension for spirited driving. With the switch in the normal "touring" position, the ride is softer.I have heard people talking about "F55" and Corvettes. What exactly is a F55 Corvette?
:goodpost::goodpost:Probably more than you wanted to know but I can't help myself. I'm an engineer, I don't do "nutshell." :rofl:
F55 is the RPO code for one of the suspension options on the Corvette.
1. Base suspension consisting of shocks and transverse composite leaf springs.
2. Z51 which has different shocks and different transverse composite leaf springs.
3. F55 Magnetic selective ride control (MSRC) which consists of magnetorheoligical fluid filled shocks which have electromagnets on the shock body, a controller and a ride control selector for sport and tour modes.
F55 Magnetic selective ride control (MSRC) which consists of magnetorheoligical fluid filled shocks which have electromagnets on the shock body, a controller and a ride control selector for sport and tour modes. The two modes vary the apparent viscosity of the fluid and change the bump and damping properties of the fluid in the shocks to regulate the ride. The F55 also interacts with the active handling system to apply shock variations at the corners that need more or less traction given input from the various sensors polled.
The MSRC suspension is a pretty cool piece of technology. The shocks are filled with a viscous fluid. Suspended within that fluid are iron particles. The outside of the shock body has magnets and sensors on it. The magnets and sensors are connected to a controller. The sensors monitor the motion and frequency of the shocks as the car moves. The controller compares the motion of shocks to a table of values and works to keep the motion within a specific range to provide the best stability and consistency. The sensors take samples from the shocks at 1,000 times per second.
When a value is recorded outside of the expected range the controller confirms the reading and works to adjust the shock to accommodate the difference. It does this by sending electrical impulses to the magnets. The magnetic field is adjusted with current flow so that it excites the metal particles in the fluid. This is called magnetorheological fluid simply meaning that it reacts to magnetism. The excitement of the metal particles causes them to change their alignment in the fluid. When this happens it changes the apparent viscosity of the fluid which causes the shock to firm up or soften depending upon where it is and how the load is measured.
Another tremendous value that the F55 package offers is that it is completely integrated with the active handling system. Unlike the base and Z51 suspension cars. The MSRC is tied in to the AH controller and when the car needs to make adjustments based on the input of the speed, steering wheel position, ABS, wheel speed and yaw sensors, a signal can also be sent to the shock to firm up or soften an area to provide the car with the best possible solution for braking or turning by adding traction and balance or taking away traction and balance to allow the car to more quickly recover from a maneuver.
The iron actually never leaves the fluid. It simply changes it's orientation. The fluid is a high viscosity liquid and the iron particles are inside a sealed cannister in suspension in the fluid. The changes in electrical charge caused the magnetic field to align and vary the orientation of the iron particulate making the fluid more easier or more difficult to compress (depending upon orientaion) as they align.GM is also the first to develop and use this type of technology, which I believe Ferrari has since picked up on and began using. I caught it on one of those factory specials or something talking about Ferrari, they said something about how it was developed 'by an American automaker' or something like that, not wanting to give credit where it's due. After all, who would want a Ferrari if they knew the Corvette had the suspension first and for half (or less) the cost lol?
One question I have, with the magnets on the outside of the shock tubes and conditions being sensed 1000 times per second, say you're driving under conditions where the magnets have the iron pulled out of the fluid, then they need to firm up very quickly, is there something to pull the iron back into the fluid or is it just released? I don't see how the iron could 'mix' back into the fluid fast enough to stiffen them with it all going at a thousand times per second. Any help?