23 replies to this topic

[smbstyle]

I have a question for the fabricators on here, to see if/how this would be done...

I am finding that my seat is a bit too upright for my taste, and would like to recline the seat a little, but my only issue is I cannot bring the seat any further forward or my knees will be in the dash, so I'd like to keep the seat in the same mounting spot it is, but tilt it back. Right now, I cannot tilt the seat back at all as it will contact the horizontal brace on the main hoop, so I am looking at having the horizontal brace "modified" so I can have a bit more room for the seat.

See the two images below, the first one is my current cage, with the straight horizontal brace across, and then a small "C" shape tube behind the drivers side for harness mounting. The second picture is the type of horizontal brace setup I would like to have. My question is how difficult would it be for a cage builder to modify my setup safely, and what would need to be done?




Here is how I would like to have the horizontal brace look; allowing more room for the seat:

[dstevens]

Piece of cake for any real fab shop. That kind of mod is pretty common in other forms of racing. We're doing one on a 76 Monte a guy bought used and wants a different seat and position.

I'd use all new tubing, notches and bends on anything you put in. It will be easier in the long run and it's not a good practice to rebend old bends though I've seen guys do it. Be sure not to grind the existing tubing too much where the old welds were so you don't gouge it and compromise wall thickness. No issue rewelding at or near the old welds as long as the joints are properly prepped and there weren't any holes blown in the tubing from poor welding.

[smbstyle]

Piece of cake for any real fab shop. That kind of mod is pretty common in other forms of racing. We're doing one on a 76 Monte a guy bought used and wants a different seat and position.

I'd use all new tubing, notches and bends on anything you put in. It will be easier in the long run and it's not a good practice to rebend old bends though I've seen guys do it. Be sure not to grind the existing tubing too much where the old welds were so you don't gouge it and compromise wall thickness. No issue rewelding at or near the old welds as long as the joints are properly prepped and there weren't any holes blown in the tubing from poor welding.

whew, good to hear. It looks like they would just take out the current horizontal cross brace AND diagonal brace, and put new ones in.

It might also be a good time to have the horizontal brace measured for me in my seat (bought the car w/ the cage from the previous owner) since I think it is welded too high up for my seating position.


Here is a better shot of the cage that I am using as an example of what I'm looking for, from the driver's side of the main hoop. It's a very interesting design, and I didn't know that was legal for a NASA or SCCA cage to attach to the back of the main hoop; I just figured it had to be one piece straight across with no bends.

[Jim Boemler]

Having a bent section behind the seat is very common -- matter of fact it might be more common than a straight tube.

[Bench Racer]

If my memory serves me correctly within the SCCA butchering the OEM shoulder belt harness column as has been done in the picture for the horizontal tube to pas through in post #3 is not allowed.

Anyone else on this ^ thought, legal or illegal in the SCCA.

[dstevens]

whew, good to hear. It looks like they would just take out the current horizontal cross brace AND diagonal brace, and put new ones in.

It might also be a good time to have the horizontal brace measured for me in my seat (bought the car w/ the cage from the previous owner) since I think it is welded too high up for my seating position.


Here is a better shot of the cage that I am using as an example of what I'm looking for, from the driver's side of the main hoop. It's a very interesting design, and I didn't know that was legal for a NASA or SCCA cage to attach to the back of the main hoop; I just figured it had to be one piece straight across with no bends.

Like Jim says, it's normal. I wouldn't fit in mine if I couldn't have that bend. Sounds like you might want to take this one to an SM shop if you aren't familiar with the cage rules. I don't know about your fab chops but you need to get familiar with the regs even if you job out the cage work. The mount points for the belts are mucho important not only for your harness to properly protect you but for your head and neck to work as it should.

I'd pitch that belt tower cut as necessary to install the cage though IIRC that may not be an allowed mod in SCCA. If it was an infraction the guy throwing paper would be riding in the Oscar Mayer mobile, that's for sure and deserve a ride on the Toro mobile, if you catch my drift. I haven't got the USB key with my books so I'll look it up later.

[Bench Racer]

.I'd pitch that belt tower cut as necessary to install the cage though IIRC that may not be an allowed mod in SCCA. If it was an infraction the guy throwing paper would be riding in the Oscar Mayer mobile, that's for sure and deserve a ride on the Toro mobile, if you catch my drift. I haven't got the USB key with my books so I'll look it up later.

Stevens, if I were to say to you exactly what you deserve Drago would throw me off his site. You'll find nothing & that means you can't do the mod. If you don't know the rules, aw never mind you wouldn't get it anyway.

[dstevens]

OK tough guy.....

[Keith Novak]

Those are pictures of my cage that have been on the site for a few years and been used for seat installation threads many times with zero complaints as to legality. On that specific mod I will argue tooth and nail 9.8.1.e: "Other than to provide for the installation of required safety equipment or other authorized modifications, no other driver/passenger compartment alterations or gutting are permitted." The towers were not removed. They were notched as little as possible to allow installation of the bar with clearance between the driver to the cage AND to put the horizontal bar at a height were the seat back brace and harness straps are at the appropriate angles for safety. The roll cage is required. The seat is required. The back brace is required. The harness is required.

The seat in the photos was one I used to show why some seats (like that one) don't fit well. The seat I use fits rather close to that bar and the harness slots are at a good angle. The IO Port back brace had to be cut to a stump to fit due to the location of the package tray and the angle of the brace. With many I've seen, in order to put the bar above the towers and get the seat back, the belts are not at a good angle to provide proper safety.

Where does it specifically say you can't modify that part to install required safety gear in the GCR since it says you can make modifications to install it? As far as I'm concerned, it's equivalent to modifying the trans tunnel which although intended to be legal, wasn't explicitly stated so until recently.

[Jim Boemler]

We had a big flap about this years ago, but it was over cases where folks were using it as an excuse to shave some weight. In a case like the one in the picture, I can't imagine anyone complaining. As for the letter of the rules, isn't there some mention of mods for required safety equipment being legal? David, what rule allows you to cut a hole through the rear bulkhead for the rear cage tubes? I would predict that whatever rule allows that hole would also allow the cut to the tower.

{edit} As usual, Keith beats me to the punch, and with better info.

[dstevens]

Yep, 9.1.8.8 e) is what allows it. That's page CGR 631 for the kids playing the home edition. I thought I read something in previous versions about specifically removing the the belt tower was not legal, can't find that now, though. That's why I said I was going to look it up later, when I had the docs. The way I read it is that if you are going to install safety gear and take bits out here and there, it's legit. I think we could agree that a proper cage with a well positioned driver, proper seat placement and mounts and properly installed restraints is what the whole spirit of that rule is all about. But then again, I don't drive an Oscar Mayer mobile, though I do love the hot dogs.

Dewhurst, what were you saying about knowing the rules?...

[smbstyle]

Those are pictures of my cage that have been on the site for a few years and been used for seat installation threads many times with zero complaints as to legality. On that specific mod I will argue tooth and nail 9.8.1.e: "Other than to provide for the installation of required safety equipment or other authorized modifications, no other driver/passenger compartment alterations or gutting are permitted." The towers were not removed. They were notched as little as possible to allow installation of the bar with clearance between the driver to the cage AND to put the horizontal bar at a height were the seat back brace and harness straps are at the appropriate angles for safety. The roll cage is required. The seat is required. The back brace is required. The harness is required.

The seat in the photos was one I used to show why some seats (like that one) don't fit well. The seat I use fits rather close to that bar and the harness slots are at a good angle. The IO Port back brace had to be cut to a stump to fit due to the location of the package tray and the angle of the brace. With many I've seen, in order to put the bar above the towers and get the seat back, the belts are not at a good angle to provide proper safety.

Where does it specifically say you can't modify that part to install required safety gear in the GCR since it says you can make modifications to install it? As far as I'm concerned, it's equivalent to modifying the trans tunnel which although intended to be legal, wasn't explicitly stated so until recently.

Keith,

Thank you for posting up those pictures! I saw them on the old Spec Miata forums, thats exactly how I'd like mine set up.

Also, you make a very good point about if you couldnt notch the towers, the horizontal brace may be in an unsafe location for mounting the harness... I think my shoulder belts are a bit too high due to that exact reason, the P.O. didn't want to notch the tower at all.

Thank you everyone for the replies!

[Sean - MiataCage]

Dewhurst..... Quit scaring people and trying to be the rule police. It is accepted and legal as per the rule Keith Novak stated. If you don't know the rules, maybe you should keep quiet.

[Jim Drago]

Those are pictures of my cage that have been on the site for a few years and been used for seat installation threads many times with zero complaints as to legality. On that specific mod I will argue tooth and nail 9.8.1.e: "Other than to provide for the installation of required safety equipment or other authorized modifications, no other driver/passenger compartment alterations or gutting are permitted." The towers were not removed. They were notched as little as possible to allow installation of the bar with clearance between the driver to the cage AND to put the horizontal bar at a height were the seat back brace and harness straps are at the appropriate angles for safety. The roll cage is required. The seat is required. The back brace is required. The harness is required.

And you would be 100% correct. IMO what you did is 100% within the rules, a more ambitious person would have taken the entire tower and IMO, still had no problems.

[smbstyle]

And you would be 100% correct. IMO what you did is 100% within the rules, a more ambitious person would have taken the entire tower and IMO, still had no problems.

Theres an idea as well, get rid of the tower entirely!

Thanks again for all the replies guys. I just got a Sparco Pro ADV to replace my Evo 2 Plus and am taking that seat and the mounts to the cage builder who is going to modify it for me, and make sure everything lines up as well.

[Bench Racer]

Jim B., from my perspective it’s not an issue of someone complaining/protesting it’s an issue of where the Spec Miata rules are allowed to slide to & the impact those sliding rules have on the future of Spec Miata. If one dared start another illegal hassle on this forum one could suggest that balancing/blue printing/parts bin blueprinting that is not allowed within Spec Miata could be eliminated using a statistical process. If it’s proven that blue printing is required to get near/or equal weight rods & pistons then it can statistically proven that blue printing has been implemented. To respond to your question of, what rule allows one to cut a hole through the rear bulkhead for the rear cage tubes/braces the rule would be Rule 9.4.B.1.c. Cars must have 2 braces extending to the rear from the main hoop and attaching to the frame or chassis. < The rule tells the legal story. For illegal hassle purposes only, one could mention rule 9.4.G.6. specifying each tube passing through the bulkhead between the driver & the fuel tank will be sealed. The GCR glossary defines the word seal.


Jim B. & Keith, I’ll agree with the 2010 thread posts that modifying the seat belt tower is not legal. I couldn’t find the earlier thread on the same subject. When I read SMCS rule 9.1.8.C.8.e. within it’s context to me the rule does not mean one may modify whatever they desire when installing safety equipment. Within the context of the same rule to me one is not allowed to eliminate the top inner door sell that has three metal thicknesses (IIRC between the two top inner door sells taken out of a F production car weighed approx 9 pounds) because one has NASCAR side protection. Now if we care to back track a bit to year 2007 the Spec Miata roll cage rule specifies that the roll cage shall meet the requirements of Showroom Stock specified in GCR section 9.4.2. Within that section the rule specifies that the roll cage shall be contained entirely within the driver/passenger compartment without removing any panel or accessory not specifically authorized in these rules. The carpeting/padding may be cut around the mounting base plates. These words “without removing any panel or accessory” within there context imply that one must not modify a SSB Miata seat belt tower would also mean one may not modify a Spec Miata seat belt tower. Please remember the Spec Miata roll cage SHALL meet the requirements of Showroom Stock. Yes, Spec Miata may remove panels/accessories/carpet. Today the roll cage rules have been condensed to Roll Cage Rules For GT and Production Based cars, with the Showroom Stock rules about not removing panel/accessory exist along with the rule to cut the carpet/padding.


And finally a phone call to a SCCA Topeka technical employee, the employee specified that modifying the seat belt tower is not legal.


EDIT: From post #15. "Theres an idea as well, get rid of the tower entirely!"


Please see post #15, this ^ is exactly how rules slide

[smbstyle]

EDIT: From post #15. "Theres an idea as well, get rid of the tower entirely!"


Please see post #15, this ^ is exactly how rules slide

Cool. I could care less about the rules for SM since this isn't a Spec Miata build. No where in my original post did I ask if it would conform to any class rules. I am just trying to see if the cage design I'm looking for is a safe design, and if my current cage can be modified to that type of horizontal brace.

[Keith Novak]

Wow. Apparently a nerve has been struck. I have lots of issues with your arguement David, like springboarding from blueprinting pistons to minor mods to improve safetyand a call to Topeka where one arguement was voiced and the nameless guy on the phone agreed but I'm off to dinner . I guess all those pesky safety concerns creeping in is why nobody wants to race vintage any more where dying from fire or a roll-over was once part of the thrill.

[Jim Boemler]

David, I support your notion of reading the rules themselves, and not being sucked down the hole of what might have slipped through in the past. But I disagree with your interpretation of the rules, and it seems everyone except one unnamed employee does too. You're all wet on this one. Soaking, sopping wet.

Sorry, I don't have a video illustration, though.

[dstevens]

Please see post #15, this ^ is exactly how rules slide