They appear on the bony portion on the outside of one’s knees after a track day in a 6th generation Corvette and are because the factory seats don’t hold your ass in place well enough. As a result — and without realizing it — you brace yourself against the door panel and the center console with your knees. After a day or two of holding yourself in place like that, bruises develop. It’s been a month since my last day on the track, and I can still find the spot where the bruise was by feeling for the painful spot.
As annoying (and kind of amusing, really) as the bruises are, the serious part of it is that not being firmly held in place by the seat is that you can’t drive as fast. Too much energy is spent trying to stay in place instead of finding those precious tenths of seconds that add up to faster lap times. And faster lap times is where it’s at… otherwise why be out on the track at all?
Gone are the days when you can bolt in a new seat, buy a harness and bar and bolt them into the car. The C6 has a side-curtain airbag in the seat, linear sensors to know where the driver is, integrated telescoping steering column (both so the airbag can be deployed accordingly), belt pre-tensioners, and seat heaters. Removing the original seat from all these systems and plugging in a race seat into its place, plus adding a 6 point harness is a daunting exercise.
The only good news is that most of the electronics are built into the seat track, and reusing that along with an aftermarket “airbag plug” — which fools the airbag system into thinking the original seat and its airbag are still there — solves most of the problems. The challenge now is to find a way to integrate the original track to an aftermarket seat. Available aftermarket seat brackets bolted to the factory seat tracks won’t work because they put the seat too high — and headroom is at a premium, especially when factoring in a helmet.
Armed with most of this information, I bought a used set of seat tracks from a wrecked Z06. From there I made my own “low-boy” adapters to get a Cobra Suzuka GT seat (that I happened to have lying around — honest) bolted to the GM seat tracks. The pre-tensioner and factory belt work, since they bolt to the seat track. I re-did the seat wiring harness to omit the heater and un-used side bolster circuits. I have a Vetteworks harness bar on order to allow the use of a Schoth 6 pt. harness when I’m on the track.
Have a look at the photographs below to see how it all turned out. I ended with a system that has nearly all the factory function, including all the original power movement minus the seat heaters and side-curtain airbag. But the best part: this seat keeps me in place, letting me concentrate on driving. And since I used a different set of seat tracks for this race seat, I can quickly swap it in for the track, and put the factory seat (and its airbag and seat heater) back in for cruising and ordinary street use.