355 Challenge Roll Cage

As we have discussed, I plan to do the same but I do not think it is feasible to build an SCCA spec cage that can be removed without leaving the steel reinforcing plates in place. Welding is process that alters the surrounding metal and I cannot see how we could restore the bolt in mounting points becuae of the distortion that the SCCA design will mandate.

I would be delighted to be shown the error of this conclusion but having recently severely and successfully tested the SCCA design, I have had cause to look closely at what goes into their proscribed mounting points and design. For example they want a front cross bar, which in the picture I sent you of the 430 at Daytona, goes right through the dash binnacle. I do not think it can be installed any lower without reducing your knee room and interfering with the steering column.

Let's see what others have to say.

 

Rob,
My car has what I believe is the "SCCA" cage, like Colin's.
Dave did do my fuel cell and some other work to the car; but the roll cage pictures in the thread are another Silver 355 that Dave had worked on just before he did the work on my, then silver, car. Mine is still bolted, but looks to be much more robust than the "FIA" cage. Fortunately, I have not tested it.

I missed MSR Houston last week, and I'm doubtful for the next few Texas races. I'm testing the 430C next week, then going to Homestead for the first race challenge race March 6-9.

Mark

 

I could not find a builder I was satisfied with so I bought a tube bender and did it myself. There is much to consider and you can't have an SCCA legal cage without it being welded. You need to read the rules of NASA and SCCA to determine how far you can go with the cage because some things move you into another class or are illegal for a class due to rules against chassis stiffening etc.. IMO if you are building a proper cage you need to first buy your seat! Your safety system starts with your seat! I can't tell you how many builders will just build you a cage and you figure out how to put the seat in. That's the best way to compromise your safety right from the start. If the builder does not talk about seats find a new builder! Next position seat in the car where you want it. Then remove all the interior. Then build the cage.

The dashbar metioned above is an integral and extremely important part of the cage. Therefore you need to remove the dash to position it properly and gut parts of the dash so the dash fits back in. There will be some compromises here liek the dashbar can't go throught the tach but you can't build a decent cage and have your knees in the impact zone. Also, you need a dashbar at the proper level to be economical with weight yet allow you to clip the right side net into its forward anchor. many clubs are now requiring full containment seats and or sidenets or soon will. Sidenets are extremely important for safety and are just as important as a properly mounted seat. In my 348 the OE mount points for the bolt in are not the best place for the weld in cage. It is important to weld the cage feet into the sill box and sill plate for strength and chassis stiffening. The 348 is a noodle and so is the 355 but the 348 is worse. My car was like new car after I went from OEM boltin challenge cage to the welded cage. Also, I cannot confirm the tubing the boltin challenge cage is made from. ERW is all but outlawed even for clubracing. Its cheap and so are the italians I bet that's what they are made from. I would need to cut one to see. DOM or chromo is the only way to go. I have researched that topic extensively and I am a DOM guy. That's a fight for another thread.

If you are a big guy go with NASCAR bars on the drivers side and X the passenger. That will give you more egress especially if you have a HANS and windownet. But if you NASCAR bar make sure to stabilize the center section of the bars with tubing to the sill box or a sill tube. I'm partial to a sill tube which adds strength and stiffness but some extra weight. I like support tabs to the sheetmetal of the car where legal. Also, this will help especially around the window frame to prevent vibrations which, stiffly sprung cars with really stiff chassis now welded, encourage cracks in the front windscreen. Those windows are like 2 grand which is why I now run lexan that cost me less than 300 bucks. If you want more post your questions...Tig vs. Mig...petty bar....HANS....clipin vs boltin harness....SFI rollbar padding....fishmouthing tubing connections

 

That's great perspective and I share your views and concerns. One thing to note in addition: if you dont put a seat support into the cage design then the seat has a max of a 5 year life under SCCA/Grand-Am and presumably NASA rules. With a set support it can be permanent fixture. Another thing probably for another thread, is make the seat a very tight fit. Its no good cinching the belets if you have an inch or more of fat compression capabilty. That squidgy stuff has to be pressed in tight otherwise on impact you will feel it. BTDT.

 

Thanks Rob! I really appreciate the support.

I'm not sure what to expect; check back with me the afternoon of March 9.

The testing, equipment and coaching investment that some of these guys have made is quite daunting. I am trying to keep my expectations realistic and hoping to have a clean first season, then go from there. The Ferrari of Houston guys have been great and the car is fabulous to drive.

It is going to be a little different experience than trailering with my dad to TWS for a NASA weekend that's for sure. Cost wise, I think of it as having a nicely prepped Factory Five Cobra, with a trailer and a pickup, tools, spares, tires, everything. Then run the weekend's races, have a great time, and then Sunday afternoon, when it's time to leave, in order to compare the cost to the Challenge Series, you set the whole rig on fire and charter a plane home!

Will it be worth it? I'll let you know.


Mark

 

Mark put it very succinctly I think. On the other hand you do get to experience the resources and professional support of one of the best teams in GT racing anywhere (presuming its Rici's outfit at FoH) and that will make you a better driver when you decide to do something else. And I agree Rob that the momentum management and lack of professional set up, makes the good SCCA drivers a cut above the guys who are able to get in at the deep end just because of their pocketbooks. I think we all join you inwishing you the best in this venture and if there are any other FC drivers on the list who read this, look after our boy please.

BTW I have heard that coaching is a valuable resource if you can get it. Especially on race craft if you have not had the boot strap experience of (like Rob's) of extensive competition in a common car series like the RX7 program. I got mine in the Mini 7 series way back when and wish that I could renew the skill that it imparted. Running the heaviest and lowest powered car at the back of the pack (as in ITE and T3) has not been a great skill builder. With that said I should have also learned how to avoid getting punted entering the pits ! Idiocy.

 

A welded cage is a whole nother level of commitment. The results are the car handles better, you are safer, but the car is arguably "done".

 

Absolutely! That's why I say the Seat is the most critical part and where you start from. I'm from the school of seat bolted to the cage not the car. When the seat is one with the cage and the cage is solid the car and the anchoring of the cage to the car are not so important. The latest pininfarina little commuter car design bears this out. The Nest as it is called has a cockpit that can collapse and absorb engery up to 14" for and aft! It uses a sled concept for extreme safety. That's what cage builders with seats connected to cages have been doing for years.

 

Not just one of the best in DFW, Todd is gaining the reputation of being one of the best in the country. I have begun to see 'For Sale' ads for race cars that specifically mention his cage as a selling point.

 

Think about:
You may want to read the latest on safety gear. NASCAR is setting the pace for tintops. The FIA flexible back thing is out of date. Look what nascar is doing with seats. Today there is no question that the seat being rigidly fixed to the cage is the way to go. The reason for this is the same reason the nylon belts are out and the polyester belts are in. The old idea of belt stretch to "ridedown" impact is obsolete. The dashbar is critical to A-piller support. I would have the builder remove the dash and test fit some tube ideas. I would plan for a right side net even if you have a containment seat. FIA containment seats have small headwings by nascar aluminum seat standards and as you know FIA seats flex. In offset crashes you get whiping and deflection outside the wings. So sidenets are still pertainant. The dashbar is your mounting point of the front part of the sidenet so that relative position is where you dashbar needs to be relative to your seating position. This is just another reason why the seat is the most important part of the safety system and where you start the build. I know you want to be original and keep dash componant position so you will need to see what you need ideally and then make your compromises as you see fit. The cobra seat has fixed shoulder hole position. You may want to confirm that the height of these holes is proper for you and your hans. You can make up for small problems in the "proper" height with seat rake. This is important to establish first because this position may change relative positions of the rollover hoop, lap anchors, and sub belt attachments all aspects of how your cage is designed. Have your builder wled tabs for your wink mirror to reduce mirror vibration. You need the wink because the headwings cut down your vision and the hans reduces your head movement and therefore visibility.

 

http://www.pegasusautoracing.com/productdetails.asp?RecId=1546

 

Me too. I have both and find the wink does not allow me to sense a change in my rear view the way I can with a one-piece. I was once told that race drivers need Lobster eyes to see all the stuff that has to be watched and I have taken that to mean that sometimes you have to sense a change rather than look for it: a needle in the wrong place; something in a mirror that was not there before; a rough surface on the track that is actually debris ... and the wink with its partitions means that there are more mirrors to watch even though with inspection you can see a whole bunch. In the years before Lexan plastic could produce relatively undistorted panoramics, we ony had the wink. Did'nt like them then either.

 

They are many options and no right answer. Fatbillybob gives great advice but there are many good variations on the theme.

If you do use a side net, it does not necessarily have to attach to the dash bar. Many secure it to the front firewall.

There is a new Hans model out that allows you to turn your head freely as the tether's anchor can now slide back and forth. I am told it can be retrofitted to previous models but have not seen this done yet. This is only an issue in the pits or entering a hot track without a flagger as a Hans does not restrict vision during normal driving (at least for me).

+1 on the panoramic mirror. Mine is clamped to the top cross bar on the roll cage. Others clip it to the stock review mirror. Others weld tabs. All work just fine. I don;t like the idea of welding tabs as that creates a fixed position. Sometimes you need minor adjustments - a new helmet, new seat, new rear wing, etc. can all create little variances to your vision that may require a little tweak to the mirror.

 

Agreed! However, many people like the front firewall just like they like subs and lapbelts anchored through the floor with big washers. I think if any one of you try jacking up your car directly under that large washer you would be horified by the deformation. I race with a hans and full containment seat and nets. There is lots of visual restriction. The allview pano mirrors are fine but the convex distortion hides small details somtimes that the wink does not. But at least use a pano with visual restrictions. Vibrations make the pano distortion worse. That's the reason for welded tabs. But it is a whatever works for you.

 

Rob,

What are you going to do about a fuel cell? Or no cell? Also, it is probably just as good an idea to do nascar bars on the drivers side and x the passenger. You will probaly not race with a passenger. I would x both sides but the nascar bars are really nice for more egress but increase your weight. It is a tradeoff

 

Agreed! I wrestle with this problem too. If I could get a 10 gal non-custom cell in the stock location I would do it. I also do not like front cells and custom is just too darn costly. ATL will do it for you however. I checked a long time ago. It was about 5000 back 5 years ago