1 Topic by Cadillac Bob (edited by Cadillac Bob 2009-12-09 11:20 AM)

  • From: Arvada, CO
  • Registered: 2009-12-09
  • Posts: 201

Topic: Advice needed: Roof/door modifications

Ok, I'm building my first Lemons car and I believe I have read the rules about as thoroughly as possible, but here's something I can't quite figure out:  What is the purpose/intent of the "sunroof rule"?

Before you ask, my goal is to shed as much weight as possible.  Keeping that in mind, why could you not remove sunroofs/t-tops if convertibles are allowed?  How about cutting holes in a hardtop roof where there were none previously?  Is this allowed?  And, to what extent?  Or to put it another way, is the rule there to promote structural integrity, or are holes in roofs just verboten?

I completely agree/understand that firewalls separating the driver from engines and fuel tanks are required, but what about doors?  Do they have to be there at all?  If no windows is OK, is no doors OK?  I'm not really serious about removing the doors but I am interested in just how far someone could possibly go from a weight reduction standpoint and still have the car pass tech.

Any advice for a newbie out there?  Thanks in advance.

--Bob

If it ain't broken, fix it 'til it is.

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  • From: Bloomington, IN
  • Registered: 2009-08-14
  • Posts: 1,525

Re: Advice needed: Roof/door modifications

I cut the whole sunroof/sunroof box out of the top of the car, and pop riveted a sheet of aluminum over it.  Had no problems with tech at all.  I know that if you don't have a roof, or sunroof you have to run arm restraints.  I put the panel in, more to keep the rain out than anything else.

Bloomington, IN
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  • Mulry
  • Mulry
  • Ayatollah of Rock-n-Rollah
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  • From: Dallas, TX
  • Registered: 2009-05-01
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Re: Advice needed: Roof/door modifications

You can totally cut your entire roof off if you want. We did it for the Topless Special that we ran at Nelson Ledges. The rule isn't there to promote structure integrity, it's a safety thing.

If you cut off your roof, use t-tops, drive a convertible, insist on having an open sunroof, etc. -- basically if you have anything over the head of the driver that is not a solid metal surface from the edges of the windshield to behind the main hoop and stretching from the top of the door frame to the top of the other door frame -- then the driver must wear arm restraints. It seems to me that these two rules should be read together for this to really make sense:

3.20: No Open Sunroofs: All sunroof openings must be covered by either the original sunroof panel; a new panel securely fixed into place; or securely fixed mesh with openings no larger than 1/2-inch each.
3.21: Open T-Tops and Convertibles: Arm restraints are required when driving an open T-Top or convertible.

FWIW, arm restraints are a total PITA.

Note that if you have a glass sunroof and choose to keep it (why would you?), then you still need to cover both sides of it with tape so that when you roll the car and shatter the roof, the bits of glass are spread mostly only on your driver and the car and not so much on the track and the other cars that didn't turtle themselves. IOW, ditch the glass roof.

In respect to the doors, many teams have run without one, two, or more doors, but it's kinda stupid. If you skin the door then you remove most of the offending weight while maintaining the weatherproofing effect of a door skin. An additional plus to skinning your doors is that you can then run NASCAR-style door bars that extend out into the door cavity. This makes it easier for the driver to get into and out of the car, but more importantly (from a safety standpoint), it provides more distance between the driver and the business end of the car that is t-boning you.

Cheers and good luck!

Pat Mulry, TARP Racing #67

Mandatory disclaimer: all opinions expressed are mine alone & not those of 24HOL, its mgmt, sponsors, etc.
  • From: North Carolina
  • Registered: 2009-11-22
  • Posts: 326

Re: Advice needed: Roof/door modifications

Mulry wrote:

In respect to the doors, many teams have run without one, two, or more doors, but it's kinda stupid. If you skin the door then you remove most of the offending weight while maintaining the weatherproofing effect of a door skin. An additional plus to skinning your doors is that you can then run NASCAR-style door bars that extend out into the door cavity. This makes it easier for the driver to get into and out of the car, but more importantly (from a safety standpoint), it provides more distance between the driver and the business end of the car that is t-boning you.

Cheers and good luck!

Pardon my ignorance (but at least I'm trying to learn!)...but does this mean that the door bars can be shaped like this:  ___/--------\___ looking down from the top?  So they don't have to be straight between the front hoop and back hoop (I know they can cross, but I wasn't aware they could bend out into the door).  A TR6 is so narrow, this would be a great asset to our larger drivers (me especially)!   Looking forward to a response!

Jamie Palmer  tr6driver@yahoo.com
Austin Powerless Racing  '75 Austin Marina, 44th/IOE Summit Point '13, 35th/1st Class C CMP Fall '13, 23rd/3rd Class C CMP Spring '14, 83rd/14th Class C CMP Fall '14 (blown engine/swapped mid-race to finish), 3rd Class C CMP Spring '15, 2nd Class C CMP Fall '15
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  • From: Detroit, MI
  • Registered: 2009-05-16
  • Posts: 1,594

Re: Advice needed: Roof/door modifications

Yes, exactly like that.  Our door was gutted such that the door bars touch the outer skin.  It gives us much more elbow room and another few inches of crumple zone.

BRE Datsun (Broke Racing Effluence) formerly Dawn of the Zed Racing
'74 260Z
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6 Reply by Mulry (edited by Mulry 2009-12-09 03:09 PM)

  • Mulry
  • Mulry
  • Ayatollah of Rock-n-Rollah
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  • From: Dallas, TX
  • Registered: 2009-05-01
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Re: Advice needed: Roof/door modifications

Here's a photo that shows what we're talking about. This isn't my car, but I like the door bars. I don't like the kneecapper dash bar smile

http://www.atsracing.net/rollcage/DSC01502.JPG

In this next one you can see how the door bar snugs right up to the inside of the skinned door panel:

http://www.atsracing.net/rollcage/DSC01503.JPG

Pat Mulry, TARP Racing #67

Mandatory disclaimer: all opinions expressed are mine alone & not those of 24HOL, its mgmt, sponsors, etc.
  • From: North Carolina
  • Registered: 2009-11-22
  • Posts: 326

Re: Advice needed: Roof/door modifications

Thanks, folks...that's just what I was asking....I may fit in this car yet!  :-)  Cool!

Jamie Palmer  tr6driver@yahoo.com
Austin Powerless Racing  '75 Austin Marina, 44th/IOE Summit Point '13, 35th/1st Class C CMP Fall '13, 23rd/3rd Class C CMP Spring '14, 83rd/14th Class C CMP Fall '14 (blown engine/swapped mid-race to finish), 3rd Class C CMP Spring '15, 2nd Class C CMP Fall '15
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  • From: Lake Orion, MI
  • Registered: 2009-10-06
  • Posts: 164

Re: Advice needed: Roof/door modifications

tr6driver wrote:

Thanks, folks...that's just what I was asking....I may fit in this car yet!  :-)  Cool!

Jamie, I should have had you take a closer look at the cage in my Spridget while you were here--same thing, the door bars bend right out to the door skin itself.  It's definitely the way to go with a narrow car like the 6 (or a Spridget, of course!); otherwise, those of us not built like jockeys would never fit!  Also, as others have pointed out, you want as much space as possible between yourself and any car that might hit you.

Enjoy every sandwich.
  • From: North Carolina
  • Registered: 2009-11-22
  • Posts: 326

Re: Advice needed: Roof/door modifications

I remembered seeing stock car cages like that, (remember building them into model kits LONG ago...) but wasn't sure that was legal for Lemons.

I was surprised to find "off the shelf" cages for TR6's, but it looks like we'll be going custom due to things like this (and a 6'3" team member)...

Flt. Lft. Palmer out...

Jamie Palmer  tr6driver@yahoo.com
Austin Powerless Racing  '75 Austin Marina, 44th/IOE Summit Point '13, 35th/1st Class C CMP Fall '13, 23rd/3rd Class C CMP Spring '14, 83rd/14th Class C CMP Fall '14 (blown engine/swapped mid-race to finish), 3rd Class C CMP Spring '15, 2nd Class C CMP Fall '15
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  • Registered: 2009-05-01
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Re: Advice needed: Roof/door modifications

Bob

There are two other considerations:
1. Weather,  If you do decide to take the top off your car or wire mesh your t-top or sun roof for weight, just remember the weather plays a big part in these races.
A wet cold driver is not a happy driver.

2. When you skin your doors take into consideration whether your doors will open or will be welded shut. In our car the drivers door was skinned so that the door bars would go all the way into the door. (Just like Mulrys Pictures) On the passenger side we completely skinned the door so all that was left was the outside panel and then we welded it in place for a permanent installation. If you do a complete skin, make sure you have a guard or splash panel in place in the fender well. If you don't, water and crap from the road surface can come into the car and cause some real problems. We know this to be the case from our experience at T-Hill. It rained on Friday and during our test session water was coming off the passenger side wheel and right into the cab. Driver wet! Radio Wet! and enough water coming in from the passenger side the drive thought he was on the "Titanic"

Just my 2 cents. Good luck with the build.

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  • From: Va Beach
  • Registered: 2009-05-01
  • Posts: 67

Re: Advice needed: Roof/door modifications

Remember to remove your parking brake handle if you have to use arm restraints...ask my why?

Going into a turn the arm restraint got wrapped over the parking brake handle and restricted my arm a this point I was freaked out and yanked than I was happy that the parking brake did no operate because it came up and released my arm.

-Mike
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  • From: WOOTville USA
  • Registered: 2009-05-06
  • Posts: 2,415

Re: Advice needed: Roof/door modifications

IcantDo55 wrote:

Remember to remove your parking brake handle if you have to use arm restraints...ask my why?

Going into a turn the arm restraint got wrapped over the parking brake handle and restricted my arm a this point I was freaked out and yanked than I was happy that the parking brake did no operate because it came up and released my arm.

I set the E-brake on the Killer Bee just before T-Hill (just goofing off, they never actually work) and the handle broke from rust as it locked the rear wheels. @#$%!

Took me a while to release it and get the car rolling again.

I never thought about the arm restraints getting caught. Did not seem to be an issue. I'm glad nothing embarrassing happened.

"Real ZomBees prefer Bacon"
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  • From: St. Louis, MO
  • Registered: 2009-09-29
  • Posts: 14

Re: Advice needed: Roof/door modifications

tr6driver wrote:

does this mean that the door bars can be shaped like this:  ___/--------\___ looking down from the top?

Whenever possible, stay away from double bends in your doorbars. An S bend is natures way of telling a doorbar where to fail.

No, it's not a rule, but you should never put more than 2 bends in a doorbar. \___________/

Scott Rhea