Last week, Mike Ryan added some support to the soft underbelly of our 1978 Chevy Malibu we love to call – GRANDMA – with our frame rails required for the 25.5 cage. It’s time to move on the roll cage structure, so we laid out our Chassis Engineering 10-point roll cage and started to get busy.

As mentioned, we decided to start off with a 10 point moly cage kit for our Malibu, and then add the necessary bars to complete the 25.5 spec cage as per the SFI rules. This is a common upgrade, and we’ll be very clear where the standard 10-pt cage ends and where the 25.5 SFI spec starts.

That means we have a lot of bars to run in the G-body, but we are starting with a good foundation. The Chassis Engineering kit comes with most of the bars pre-bent in the kit, including the main hoop, top hoop, and a-pillar bars – which are very difficult to bend yourself. All that was required there was to fit, hold and weld.

Chassis Engineering was good to us. Not only did they supply the cage, but they supplied the mini-tubs, parachute mount, parachute cable, misc. accessories, but even – get this – a driveshaft loop. I know, they hooked a brother up!

Coming out of the box, here is the Chassis Engineering pre-bent main hoop and top halo bar. This would be the starting point for the kit. Mike started by cutting out two small holes in the floorpan so that we can run the main hoop down to the frame rails as per NHRA and SFI spec.

After taking a few measurements, he cut the legs of the pre-bent main hoop to fit inside our Malibu with enough room for a head liner. When he was happy with the fitment and clearance at the top for the headliner and all around the main hoop, he tack welded it in.

Mike says that for him, it is easier to do most of the main hoop section in the car, tack welding it in at first; then bring it out of the car for final welding. That way he has plenty of room to lay down a nice tig welded bead on the cage without interference from anything else. This is where our 25.5 upgrade came in. We would need to add the rear bars for the funny car cage upgrade that sit behind the driver’s seat.

Here Mike tig welds the rear part of the funny car cage upgrade – required as per SFI 25.5 – to the Chassis Engineering main hoop. The 25.5 upgrade required two modifications to the standard main hoop. First, the cross bar was mounted lower than the standard area on a 10-pt, and second, the two funny car rear bars are welded behind the driver’s seat.

Here is a sweat trick we didn’t know. Before Mike welded the main hoop in, he made these trick plates with a clearanced hole with a hole saw, so that you have a completely sealed and clean floor with the cage going through it.

With the main hoop installed, next on the list was the two rear down bars from the top of the main hoop that run down to the rear trunk cross bar Mike welded under the trunk last week. He started by cutting two slots in the rear deck to give the bars plenty of clearance to run down into the trunk area. Mike plans to use some sheet metal later to fill these in after all of the necessary bars have been run through that area.

Again grabbing from the Chassis Engineering kit, Mike cut the bars down to size and bent them in the rear of the car. After fitting the bars in mike made two similar floor plates as he did for the main hoop and welded everything in. Chassis supplies the rear bars straight here giving you flexibility in your installation. Some install straight bars but we preferred to bend ours.

The complete rear down bars. See how clean they look with Mike’s trick plates. Once this area gets cleaned and painted you’ll see what nice work this is. It’s just obscured by 6 different kinds of metal surfaces.

Here is a shot showing where the bars are welded into from under the car. This is our rear cross bar that will eventually partially support our fuel cell and battery trays.

Here is another angle of the rear of the car, the C/E mini-tubs, main hoop, and rear down bars. As mentioned, you can see the main hoop with the start of the funny car cage installed in the car on the right. Notice how the cross bar is mounted lower than you would normally see in a 10-pt cage.

From there Mike was on to the halo bar. Again another easy install as the only thing Mike had to do to fit the Chassis Engineering piece in was cut it down to size and notch the bar so it fit flush against the main hoop and weld it in.

The last thing Mike got to was cutting two holes in the floor just like he did for mounting the main hoop, only this time, it is in the front of the car just in front of where the driver seat will mount. This is where the bar running from the halo bar will come down and attach to the frame. We refer to these are front down bars.

Check back in later this week, Mike will be fitting more and more of the cage in the car as we continue to bring you updates all the way till this car is running on the track. Our goal is provide you with a step by step guide to building your own 8-second Malibu with common every day components and off-the-shelf parts.

Until next time, we’re out.