Posts Tagged ‘roll cage’

Setting up a Seven – Safety

Thursday, April 1st, 2010

As you can see from the picture above, when I got the Ultralite it came with a simple asymmetrical rollbar that was barely taller than my head. While most track clubs would let me drive the car as is, the lack of side impact protection meant that I was not comfortable tracking the car without a full roll cage. Additionally the existing Ultrashield race seat had no head and neck support and the harnesses were long expired which meant I generally had to perform a full safety upgrade before tracking the car. For this I turned to Tony at TC Design who is the Bay Area’s premier roll cage fabricator.

Roll Cage
After looking at some of the existing cage designs for the Ultralite we decided to go for a design that had single high rear hoop and two side impact bars on each side.

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The two side impact bars tie into the existing chassis hoop that holds the dash in place before the top bar extends further up to the main chassis rails.

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Additionally they welded in a new square tube section within the chassis to act as a load path for the upper impact bar.

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The next step is to paint the cage and add some SFI spec padding for extra protection in an impact.

Race Seat
The biggest difficulty in putting a race seat into a Seven is usually the severe lack of space. Surprisingly my biggest problem with the existing seat was actually the fact that it was too big for me. I was getting thrown around between the two rib cage supports and the supports also interfered with my left elbow while making large steering inputs. Additionally the seat was completely lacking in lumbar support and even though I tried putting in some additional padding in various positions I would invariably end up with some back pain if i drove it for over an hour. My initial plan was to go with a custom Kirkey seat with full HALO support but after the back pain issues I decided to put in a composite seat instead. Composite seats are generally a lot more comfortable (I’ve done 4+ hour stints in the Lemon) and they have a one-size fits all approach which means you don’t have to screw around with measurements for every specification.

OMP Pista

After deciding on the composite seat, I pulled the existing seat out of the car to measure the width of the cockpit to see how much internal room I would have. The 18.5 inch width, along with my HALO requirement meant that there were very few seats I could actually consider. The two main seats I narrowed it down to were the Sparco Circuit Pro and the OMP Pista. Both are FIA homologated with full Halo support and were narrow enough to fit in the car. I then contacted Wine Country Motorsports to see if I could try out the OMP Pista before purchasing it. Mike @ Wine Country was fantastic to deal with and was happy to help me not only try out the seat but also to test fit in the Seven to make sure the measurements would fit. After trying it out I found that it was a snug fit (I likely wouldn’t have fit in it 2 years ago) but was very comfortable and holes in the HALO support afforded excellent visibility as well. After buying the seat I took it back to TC Design to have them fabricate the necessary mounts and fit it in the car.

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The seat is now mounted using 4 bolts going through the car floor and attached using large size backing washers. Also it may not be visible from the pictures but the left edge of seat us actually under the chassis tube – this is literally the largest possible seat you could fit into the car without modifying the transmission tunnel.

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Point to note is that the cage had to be modified so that the side impact bars would clear the halo wings of the drivers seat. It did not have to flare on the passenger side since I do not plan on fitting in a HALO seat and there is no room to fit one in either (passenger area is 2 inches narrower than the drivers side). The other unfortunate side effect is that my legs are now slightly higher in the car which means that my knees interfere with the stock steering wheel. I removed the seat bottom padding to drop myself lower into the car seat but still had to move to a smaller steering wheel to get the full range of motion. While the smaller wheel is ok at speed, it does make driving a lot more physical at low speed and in hard turns (T11 at Laguna is tough).

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Racing Harnesses
Since the harnesses in the car had expired several years ago (SFI belts expire in 2 years) , I had to get a new set of harnesses. Having used a several different belts over the years I decided to go for the Scroth Profi II 6-point belts since I find their adjustment system to be the fastest and easiest to use. The other feature I like the way the lap belts can be configured to pull-up tightening which allows you to strap yourself in tighter without any outside help. The final step was to add a set of arm-restraints though I will likely use them only on track days and not on the street (I use my helmet and R3 on the street)

Conclusion
All in all it was a pretty expensive and slow process to go through all the safety upgrades but it is a one-time thing and should now last me for several years. I have to give a huge thanks to TC Design for doing a fantastic job with the full safety setup and also squeezing me into their busy schedule. Thanks also to Wine Country Motorsports for letting me try out the seat before actually buying it.

You can see more pictures of the cage and seat installation at in my Flickr set. Click here for the rest of my “Setting up a Seven” series.

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Days 4 and 5 – Its all about the cage

Tuesday, October 9th, 2007

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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