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24 Hours of Lemons cars

Days 4 and 5 – Its all about the cage

One of the most important pieces of safety equipment for any racecar is the roll cage. Having seen one car flip in July event, we knew that this one part we we had to take very seriously. The official rules for the race only require a 4 point roll bar and a door bar, but we decided to go all the way and get a full roll cage instead. In fact, one of the reasons we went with the E30 was availability of several bolt-in roll cages for the spec E30 market. After looking around for a bit and contacting several companies, we decided that an Autopower roll cage was the way to go. Their cages are legal for both SCCA and NASA and they are universally regarded as one of the best cage builders in the business. Additionally since they are one of the largest manufacturers of bolt-in cages, we knew that they cage would be well designed and would bolt in with a minimum of fuss.

The next step was actually buy the cage, Autopower does not sell to directly to clients so we had to find a distributor. When I looked up the list I was happy to see that Livermore Performance was one of their distributors. I have been buying brake pads from Monty and Stephen ever since I moved to California, and its always been a pleasure to work with them. When I spoke to them about our Lemons team they were very interested and signed on to become a sponsor. At this point the race was just a month away, and the regular 4 week lead time for a cage would have been too slow, luckily Livermore Performance and Autopower worked some magic and were able to rush us a cage in just 10 days.

Roll cage instructions

Roll cage

The cage arrived as a set of shaped and welded steel tubes which we painted and left to dry overnight. After that we put the car on the lift at Dietch Werks and got to work fitting in the cage. The back section with the actual roll hoop went in fairly smoothly as did the front windshield bars. The door bars did however cause some interesting issues due to the placement and width of the B-pillar post. The roll cage was designed to fit an E30 coupe since that is the car most commonly used in the Spec E30 class. On a 4 door E30 like ours, the b pillar post is about 8 inches further forward than in the coupe which meant that the main cage roll hoop would not line up with the B pillar. Normally this wouldn’t be an issue (you cant use the back door but that not really a concern in a race car), but since the door bars curve outwards from the roll hoop they were hitting the B-pillar and would not fit in place. The solution was to use a sledgehammer and bend the inner sheetmetal of B-pillar about half an inch outwards. This does affect the structural integrity of the pillar, but since we are doing it to put a full roll cage, the car is going to be considerably stronger than stock.
Before

After - needed to make some space for the door bar

Once the full cage was in place, we drilled holes in the sheet metal and bolted the cage to the car with the included high grade bolts and mounting plates. The final step was to tie the various pieces of the cage using the supplied sleeves which would be bolted across the joints in the cage. This required us to drill a 3/8th inch holes through the sleeve and the cage so we could pass a bolt through. Now this may sound simple but it was actually by far the slowest job. The cage steel is so hard that it takes 10-15 minutes to drill just a single hole and we needed 16 holes in all which meant that it took us a full day just to fit the sleeves. On the plus side though I will feel extremely safe sitting in a car with such a strong cage 🙂

Drilling the roll cage mounts

All in all the cage install was a fairly simple process and needed only the most basic tools. It may add weight to the car but in terms of improved safety and chassis rigidity it is one mod that was well worth time, money and effort. If you ever need a roll cage, I strongly recommend buying the Autopower cage from Livermore Performance.

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