THSCC Forums

Karl, out of curiosity, what is it about this bar that wouldn't pass? Forward bracing not at 30 degree requirement, or something about the main hoop triangulation (which has loose wording in the SCCA Solo rulebook)?


So, I haven't found this requirement in the Solo rule book or specifically called out in our Tech guide. In fact there are a few example pictures in our tech guide where the rearward legs are curved. Are you sure this is a requirement? I'm interested in this one for my own reasons....

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Dustin Fredrickson
-- I'm a nobody --

Let me remind everyone that answers on this forum are not official answers, even if they come from officials ... any safety requirement must be cleared by Vitacco and Cooper if there's a question.

Now... having said that: the way I see it, we MIGHT approve this bar for DE events, but not for time trial. OF course, thats assuming a passable broomstick test. The main problems I see with the design are:

1. It kinda doesn't have ANY rearward bracing. The angle of the bar is asking for it to fail backwards.
2. It doesn't have any cross support
3. It doesn't provide for proper harness mounting



I haven't seen a Cusco bar I'd put in any car yet ... small tubing, bolt-together main hoops and bracing, numerous bends in weird places.

Again ... however, again, Mark has been known to approve something for the DE, but not the TT, and that might fall into that category.

But again, and I can't stress it enough... any questionable safety feature MUST be cleared by Vitacco and/or Cooper.

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Stacy King
Midlife Crisis Participant

I'm not altogether sure that it "wouldn't pass" inspection - but I'm unsure enough that, for me, it's out of play. One of the big things that you may have missed is that, at least by looking at this picture, you have to remove the factory roll hoops to make it fit. Which isn't something I want to do. Whether or not that would even be legal for AS is an open item...you can cut trim to fit around a roll bar, but removing the hoops underneath - which could be construed as structural members - that's questionable.

Beyond that, the "main hoop" is in the "back of the triangle," if you will, rather than the more conventional front. Stacy already touched on this - it looks, to me, as though it would be likely to fail backwards. Additionally, it lacks diagonal support, and lacks a cross bar for mounting harnesses.



No, I'm not sure of it. But, to me, curves in a place like that are asking for it. Even with them being curved in an outward fashion - which they are - it still seems like a place where I'd want straight tubes. Moreover, they bolt on, which is even that much worse. Here's a picture:



Something along the lines of the Mugen might pass our tech for DE use, and if it would, I'd consider...for a minute. But, for all of the above mentioned reasons, I'd be unlikely to pull the trigger.

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

OK forgive the horrible MS Paint hack job.

Can the main hoop bend outside a single plane? I'm assuming the rear supports must connect to the main hoop - what if you had the main hoop bulge slightly rearward to meet them, possibly with a straight brace welded across the top like a 'mini-halo'. Then weld a straight bar between the 2 uprights for harnesses (or must this also link directly to the main hoop?)

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One of those LeMonHeads...
91/95 Miata, 02 Focus SVT, 01 Ford F250, 09 Suzuki SV650SF
rusty 84 C4 Vette, tiny piece of the General Lei
Irish Sport Horse - 1hp NA!

I'm not sure, Kendt. I'm not sure what, exactly, the rear legs connect to - nor am I sure if the convertible top would still open and close if you started to get clever back there. It's really tight for space back there (and I suspect Jason's situation with the PRH is the same).

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

No.

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Has no responsibility whatsoever.

If your registration say "convertible" it needs a roll bar.
See our Tech Guide in the TRACK part of the THSCC web site
or www.timetrials.net There were 2009 roll bar updates that will
apply to your type of vehicle.

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Mark Vitacco
THSCC TT Chairman
mvitacco@bellsouth.net

What you want is to find or build a roll bar with at least one diagonal support.
Lack of Diagnal support is where many designs fail.
The upright support can incorporate the rear bulkhead of the vehicle.
I have seen this done on the new Miata. ALso, check
the 2009 version of our Tech Guide and the 08-09 SCCA TTR LEVEL3
roll bar rules for the new tubing specs. Now that EWT is outlawed
and DOM or Alloy tubing is mandatory, tubing size is smaller, which will
help if you are space limited.

Locally I would recommend Competition Cages, Bethenia Garage, or
Apex Racing to have one built for you to spec. These guys know how
to do an SCCA-TTR Level 3/Level 4 spec roll bar that we require.

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Mark Vitacco
THSCC TT Chairman
mvitacco@bellsouth.net

Took me a while to find the TTR SPEC, so here it is in case anybody else doesn't feel like searching:

http://www.scca.com/documents/Club%20Ru ... Trials.pdf

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Dustin Fredrickson
-- I'm a nobody --

Karl:

Are you still on the Track Receiver list? I sent out an email with
the Tech Guide Updates. We are allowing the rear bulkhead to
be incorporated as the upright support. This is done on many
of the Factory Five vehicles, Boxter, Lotus, and new Miata.

That solves most of the problems of getting a roll bar in a
car with a rear bulkhead directly behind the driver seat.

Where many designs still fall short is lack of any diagnal
support. I've seen some designs (Viper and S2000) where
additional short uprights were installed on the diagnal to
serve both purposes (additional veritical and diagnal support).

The main hoop can follow the contours
of the side of the tub. SCCR TTR allows 4 bends in the main hoop.
Itf more than 4 bends, go one up in wall thickness size. It's always desireable to have streight tubing but that may not always be possible if you can't anchor it do something substantial. The "one size fits all " roll bar in the old SOLO1 Appendex J is just not going to happen in some of the newer sports cars. Some of them must be evaulated on a case by case basis but diagnal support (as well as verticle) is mandatory.

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Mark Vitacco
THSCC TT Chairman
mvitacco@bellsouth.net

Track Tirals?!

Spellczech FTW!

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One of those LeMonHeads...
91/95 Miata, 02 Focus SVT, 01 Ford F250, 09 Suzuki SV650SF
rusty 84 C4 Vette, tiny piece of the General Lei
Irish Sport Horse - 1hp NA!

I just had a long discussion with Karl S about these S2000 roll bars.
There is not a problem with either of these roll bars based on what I can see in the photos.

1) The Tech Guide and TTR states a roll bar must have two upright
supports. It is not a requirement an upright be rear facing.
For the Tech Guide I added clearification, stating to the effect,
in some vehicles, the rear bulkhead can be part of the upright support,
as done on Boxters, Lotus's, Factory 5's, and one Dodge Viper bar we documented. We can't actually see how this is done in the photos but
its possible the bulhead rear & shock towers can be part of the upright
support structure. Need more photos and data to make the call. Again,
go back to Factory 5, Porsche Boxters, etc.

2) At least one diagonal support is required. There can be
two diagonal supports. It's possible the diagonal can also
be an upright so long as its a 4 point bar and not a tripod or 3 pt.
Diagonal supports can be removeable.
Both the Tech Guide and TTR contain drawing examples of removeable
joints. The joint in the photo matches the drawing in our Tech Guide.


3) 4 bends are allowed on the main hoop. The bottom can bend
in or out to reach a hard point or provide seat back clearance.
The bend in the top is not a show stopper severity of bend or
exceeding 4 bends will require .120 wall thickness vs .095

4) When reading the SCCA TTR, we comply to what SCCA calls
LEVEL3 in the TTR.

5) A Harness bar should be a horizontal tube on the main
hoop but using the rear bulkhead is acceptable so long as the
harness mounts are GCR/SFI compliant.

I believe either of these bars will be TT complaint.
Would need more photos of the actual mounting and the tube size to be sure, but they appear to meet the minimum TTR requirements.

Can you get more photos and the tube size spec's?
Then we can make the call for sure. I would be happy to add photos example for the Tech Guide.

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Mark Vitacco
THSCC TT Chairman
mvitacco@bellsouth.net

The information I'm finding on the Cusco (the blue one) is sort of all over the place.

This place says the bars are 40mm - no wall thickness specified: http://www.vividracing.com/catalog/cusc ... -5104.html. Of course, it also says that the bar "won't work on vehicles with a sunroof or moonroof," so the whole page seems suspect.

This thread, on s2ki.com, is about five years old now - but it does raise some issues with the Cusco bar: http://www.s2ki.com/forums/index.php?sh ... try4145008 I can't help noticing that the places that sell the Cusco bar often make a point of mentioning that it's chromoly, and very light weight. Which leads me to believe the wall thickness on the tubing might not be up to standard. So far, I haven't found the actual data.

So...here's a picture of a version of the Cusco from a different angle:



And, it demonstrates a problem - at least, a problem for my particular case. Notice the way the main hoop goes down the bulkhead, to the floor. That's fine and all - but, if you want to keep the factory seats, you're forced to give up about 3 inches of seat adjustability. This with a car that isn't famous for having a lot of room in it.

So now, you're faced with either cutting up the factory seats, or, more likely, fitting a pair of racing seats. Which, I think, is necessary anyway, to get the harness belts to work properly. This takes the car out of A Stock, which isn't something I want to do.

The right solution, for me, is probably to start hunting for a salvage title S2000. Something I wouldn't care as much about cutting up. This one's way too nice for all this.

I'm looking for better pictures of the Mugen bar. It looks to me like the main hoop legs go fairly far forward into the floor of the car - if that's so, the same seating problems reveal themselves.

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

Mugen roll bar pictures:

http://www.gotuning.com/product_info.ph ... cts_id=857

I'd just post the image itself, but something on their website is borked, and I can't figure out how to make it work.

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

And here is a picture of what's underneath the black plastic trim for the factory hoops:



Getting back to the Mugen one, if you look at this diagram, notice the places towards the center of the cockpit where the factory hoops attach. That's what the Mugen attaches to.

I just found another problem with the Mugen, which could be far more of a showstopper than the others. The factory three point seat belts attach to the stock roll hoops - I just verified this on my own car. To use the Mugen, you'd have to lose the stock seat belts, or at the very least, engineer a way to put them somewhere else. Ugh.

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)