Installing Schnell Autosports' Exclusive Rear Support Bar

Schnell Autosports’ rear support bar is a quick and easy way to make your 981 Boxster or Cayman handle better. There are two frame rails at the rear of the car that are connected to one another by only a stamped piece of metal. Under hard cornering or other unbalanced loading, that plate flexes, which in turn allows the two rails to flex. Installing Schnell’s rear support bar will solidly connect the two rails together, minimizing any unwanted movement during spirited driving.

The installation process is simple to do, and only the following tools are required:

• Socket wrench with 16mm socket
• 19mm wrench

You will want to preassemble the center support bar first. The jam nuts should already be installed on the rod ends, so just thread the rod ends onto the support bar. Please keep in mind that the bar is left hand threaded on one side, and right hand threaded on the other, and the kit comes with one left hand threaded, and one right hand threaded rod end. If you are having difficulties threading a rod end into the bar, try turning in the opposite direction, or try the other side.

After securely raising the rear of your car, you need to remove 4 nuts that attach the rails to the plate using the 16mm socket.

With the nuts removed, you can now install the support bar end plates. Make sure the end plates are oriented the correct way; the “raised” section that the bar will attach to should be on the side facing towards the center of the car, with the “flat” section with the holes for the bolt studs on the side facing the rear of the car. Also, make sure that the slots on both plates are perpendicular to the length of the car, so that the bar when installed will be perpendicular to the length of the car as well.  Once you’re sure the end plates are in the correct position, you can then reinstall the nuts that you removed prior.

With the end plates securely mounted, now you can install the pre-assembled rear support bar.

The rod ends will fit into the slots of the end plates. Align the holes of the end plates with the hole of the rod end, and insert the provided bolt through the end plate. The head of the bolt should be pointing towards the rear of the car, and there is a notched area on the end plate designed for the head of the bolt to sit in (to prevent the bolt from rotating). You may have to rotate the rear support bar to make the overall length longer or shorter so that both holes line up.

Once the bolts are inserted,  place the lock washer onto a bolt (on the side facing away from the rear of the car), and then screw the nut on the bolt until hand tight. Repeat for the other side. Once you have the lock washers and nuts installed on both sides, you can tighten up the nuts on both sides with your 19mm wrench. Tighten them until snug, and then give it another ¼ turn to compress the lock washer.

All that’s left is to set the preload on the bar. To do this, you need to rotate the bar so that the overall length becomes longer, so that the bar is pushing outwards on the rails. First loosen the jam nuts so that they are not in contact with the center bar (to make it easier to rotate the bar). From there, turn the bar so that it becomes wider. A quick way to tell if you’re going in the right direction is that you will see more threads become exposed on the rod ends. For most installations, this means rotating the bar so that the Schnell Autosports logo moves downwards. Ideally, you will want the bar turned so that the Schnell Autosports logo is facing towards the rear of the car, with the wider portions of the bar being parallel to the ground. There are two holes on the support bar; one on the thinner side of the bar to the right of the sticker, and one on the wider side of the bar, to the left of where the sticker is. Those holes are for the insertion of any sturdy tool that will fit (the holes were designed specifically to fit a ¼” center punch), so that you can give yourself extra leverage to rotate the bar into position.

Once you’re happy with the bar’s position, you can tighten the jam nuts. Rotate the nuts until they are against the bar (remember, one is left hand threaded, one is right hand threaded), and then tighten them with your 19mm wrench. You may have to hold the bar in place while tightening the jam nuts to keep the bar from rotating.

With the jam nuts tightened, you’re all done. Get your car back on the ground and go for a ride.