The 24 Hours of Lemons Forums → Lemons Tech → Cage question, Roof Support - can we cut it and gut it?
So, we're building a cage:
Up at the front a-pillar the halo bar sure hits the roof support. We could get an extra 2 or 3 inches of head room if we trimmed the roof support:
Here's where it interferes:
So my question is this - there's no issue with trimming up that roof support is there? The rules say you can't mess with the crash structure outside of the wheelbase - any issue with the roof? We could use that extra 2 inches...
Shorted the halo bar so that it is further rearward and clears the support structure. There is no "rule" that says where the front part of the bar has to be. It's best to be as far forward as possible but of the cages I helped build we always fit the halo bar along side of the "structure" and not below it.
Looking at the pictures of your halo bar I can see that it's to wide in the front. Bend up a new piece of tubing and make it narrower so that it fits better in the front.
Looking at the pictures of your halo bar I can see that it's to wide in the front. Bend up a new piece of tubing and make it narrower so that it fits better in the front.
Okay, I'm tracking with what you're saying, I think.
You suggest it's OK to bend up a halo bar that sits flat against the roof, inside of the supports that you can see in this picture? Am I understanding your comments correctly:
Yes that's correct.
Yes that's correct.
Yup, up, and nested inside the supports. Make sure your weld goes all the way around the tubes in the rear. Some people cut holes in the floor, drop the cage into them for the weld, then pull it back up to slide in the spreader plates. Whatever you do, make sure you weld the top.
Good luck!
If they allow convertibles then why can't you cut out that section?
Bill
If they allow convertibles then why can't you cut out that section?
My understanding of the rules is that you might get away with cutting it or you might not, but either way the preferred solution from both a safety standpoint and a rules standpoint is to leave it alone and build in conjunction with its presence. The overall structure of a factory convertible, at least a modern-ish one, was designed with the absence of a top in mind. This vehicle was not.
3.D.2 OE Crush Structures. Modifications that reduce the size and/or effectiveness of OE crush structures -- including but not limited to shortening or removing frame rails or unibody structures outside the wheelbase -- are discouraged in the strongest possible terms. Cars with compromised OE crush structures are exceedingly likely to fail tech. Non-OE replacement crush structures are not an acceptable substitute; you and your stick welder ain't NHTSA.
Help is available in the Baltimore area if you need it.
https://www.youtube.com/watch?feature=p … p_Ok#t=100
FWIW, roof is not "outside the wheelbase", so have at it. Especially if it's only a little bit of trimming. The reason why we got chewed out so hard for the minivan is because we took the entire roof off, including metal back of the C-pillar - which is outside the wheelbase, and thus not kosher to tamper with unless approved.
Unless you're going for absolute win, I wouldn't worry about rigidity loss. The cage will generally compensate for whatever you cut off, especially if your dash bar goes out to the a-pillar root.
we are running an 84 Trans Am t-top car...all of our roof structure is gone. SO yes you can cut it out, You can also get rid of another 200+lbs of "structure" if you so desire.
we are running an 84 Trans Am t-top car...all of our roof structure is gone. SO yes you can cut it out, You can also get rid of another 200+lbs of "structure" if you so desire.
Mr. Yuck, meant to talk to you guys about this at the race as we have t-tops too just got busy fixing our cars and others. A team mate checked it out though. Why did you not just make it a convertible? Is what is left adding much to the structure?
FWIW, roof is not "outside the wheelbase", so have at it. Especially if it's only a little bit of trimming. The reason why we got chewed out so hard for the minivan is because we took the entire roof off, including metal back of the C-pillar - which is outside the wheelbase, and thus not kosher to tamper with unless approved.
Unless you're going for absolute win, I wouldn't worry about rigidity loss. The cage will generally compensate for whatever you cut off, especially if your dash bar goes out to the a-pillar root.
That and the fact that it was about as structurally rigid as a Soft Taco Shell.
Mr.Yuck wrote:we are running an 84 Trans Am t-top car...all of our roof structure is gone. SO yes you can cut it out, You can also get rid of another 200+lbs of "structure" if you so desire.
Mr. Yuck, meant to talk to you guys about this at the race as we have t-tops too just got busy fixing our cars and others. A team mate checked it out though. Why did you not just make it a convertible? Is what is left adding much to the structure?
Because T-Tops man! Respect the Mullet!
we are running an 84 Trans Am t-top car...all of our roof structure is gone. SO yes you can cut it out, You can also get rid of another 200+lbs of "structure" if you so desire.
Is that the gold #907?
actually I think I found it - colored zebra print #35
meyers0150 wrote:Mr.Yuck wrote:we are running an 84 Trans Am t-top car...all of our roof structure is gone. SO yes you can cut it out, You can also get rid of another 200+lbs of "structure" if you so desire.
Mr. Yuck, meant to talk to you guys about this at the race as we have t-tops too just got busy fixing our cars and others. A team mate checked it out though. Why did you not just make it a convertible? Is what is left adding much to the structure?
Because T-Tops man! Respect the Mullet!
I rocked the Mullet in 84 for sure.
ICE we drive a white T/A #801
We wanted a roofed car in case of rain. We made up a sheet metal piece to cover the big hole. It can be removed easy. It is also cheaper this way. If you run an open roof you have to have a massive safety net in place.
this is the car. 
No safety net required for an open roof. Just arm bands that cost about $25.
No safety net required for an open roof. Just arm bands that cost about $25.
Not in Chumpcar....
meyers0150 wrote:No safety net required for an open roof. Just arm bands that cost about $25.
Not in Chumpcar....
I was under the impression that they rescinded the ridiculous roof net rule and require arm restraints instead for open top cars.
Mr.Yuck wrote:meyers0150 wrote:No safety net required for an open roof. Just arm bands that cost about $25.
Not in Chumpcar....
I was under the impression that they rescinded the ridiculous roof net rule and require arm restraints instead for open top cars.
not sure
The 24 Hours of Lemons Forums → Lemons Tech → Cage question, Roof Support - can we cut it and gut it?
