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Rules Clarification: Cage through the floor pan question


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Posted

There is a car being built in TX for AI which uses a cross car beam that cuts through the floor pan rather than going over it. This beam is then connected to another bar which looks to be 4" away to support the 3rd link coming into the cabin. A pic is below:

 

2_3%20SVO%20009.jpg

 

We asked about putting a cross car beam in the Blue #29 car we built last year and were told specifically that the bar was not to go through the floor pan, ie. don't cut the pan to accomidate the cage, and in this instance it is clearly cut into the pan.

 

Though that bar supports the mount for the 3rd link it clearly could have been ontop of the floorpan like we did in the pic below:

 

DSCN1572.JPG

 

The rules state:

2005 AI Rules 7.3(g)

The floorpan may be modified for the purpose of facilitating the installation of a three-link type suspension. Such modification is limited to a hole being cut in the floorpan to allow the “third link” to pass through the floorpan to the attachment point in the cockpit.

 

Is my interpretation of the rules correct in saying that you can cut the pan for the actual pass through of the 3rd link but not to accomidate fabrication of the cage? That is what we were told in our car almost exactly a year ago.

 

Is this legal for AI?

 

Thanks!

 

bpt

Posted

5.12 Roll Cage The roll cage must comply with the roll cage standards of the NASA CCR. However, a roll cage may also provide additional chassis stiffening through the use of alternative mounting points. As such, the roll cage mounting points are unrestricted. The roll cage may also pass through the firewall and attach to the front shock towers. Additional bracing may also be welded to the front of the shock tower and extend forward and down to the forward most part of the original frame rail. This bracing may not pass through the shock tower and must not form the upper mounting point for an aftermarket SLA system as the SLA must still remain within the original shock tower. The mounting plate material must conform to the specification in the NASA CCR but the plate size and design is unrestricted. Interior body panels and sheetmetal may be bent or altered to accommodate the roll bar design.

 

 

 

 

I'd say the last sentence makes that legal...

Posted

The Car in question is mine. The referenced bar is not part of the roll cage, the bar was put in after roll cage fabrication with the sole purpose of supporting the front lower mount of the third link. An unprejudiced, clean reading of the third link allowance for cutting of the floorplan allows this mounting. We completed this construction after reading of the allowance by two car builders and the threads related to floorpans that accompanied the debate over the 2005 rule revisions. The rule in question is not the roll cage, but the third link allowance. The installation should be found legal.

 

Bob Holmes

Posted

Sorry about that.....I just assumed (yeah I know) you'd want to mount the upper link to the roll cage. Looks legal to me.

Posted (edited)

I probably need to get a picture of the front mount position in its lowest position. The picture shown does not show link in a position that would be used for racing. It will become clear that the front mount may be lower than the floor pan with the rear mount above. Hasn't anyone else put one of these together? Given the concerns stated on Corner-Carvers, it appears that folks were denied the ability to use the cross brace for their roll cages, while my issue is that I'm using it for a third link mount.

 

Bob

Edited by Guest
Posted

Bob,

Are you building the car in Calif to race in Texas???

 

-=- Todd

Posted

Nope, I just plan to run a couple of events in California. Thunderhill, Sears Point.

 

Bob

Posted

One additional clarification. The rollcage and third link fabrication was completed in November of 2004. At that time the rule read:

 

" The flooplan may be modified for the purpose of facilitating the installation of suspension components such as a three-link suspension. All components that intrude into the cockpit must be covered."

 

I don't know if anyone remembers my rant about rules stability and the impact of changing rules during the car building season. I sure do!

 

Bob

Posted
One additional clarification. The rollcage and third link fabrication was completed in November of 2004. At that time the rule read:

 

" The flooplan may be modified for the purpose of facilitating the installation of suspension components such as a three-link suspension. All components that intrude into the cockpit must be covered."

 

I don't know if anyone remembers my rant about rules stability and the impact of changing rules during the car building season. I sure do!

 

Bob

 

Did your car have a 2004 logbook? Good Luck.

Posted

I'm trying to finish the car. How do we get this question settled? Any help would be appreciated.

 

Bob Holmes

Posted

Bob-

 

The Directors are discussing this right now and we'll have an answer for you next week when a few people get back from vacation.

 

-JWL

Posted

John, why would the answer you give this guy be any different from the answer you gave us over a year ago?

 

What about the 'slippery slope of tube frame cars' logic that you used while saying no to me on this very subject?

 

The mount for the 3rd link could have been made just as strong by not cutting out a large section of the floorpan to insert the rollcage through. If this goes through it opens the door to many other 'chassis mounting' ideas that involve cutting the pan out and replacing it with tubing.

 

bpt

Posted

Don't worry about it too much, Brian. I just want to make sure all the directors get to look at the pictures and understand what's going on before we make a ruling. We try to make these rulings as a team, so this often involved a little waiting and discussion to get things right.

 

-JWL

Posted

Thank you JWL. "This guy" would like to make it clear that the bar in question, which cuts through the floorplan is a mount for a third link. Regardless of the other characterizations, that is what it is for. The total area of the floorplan that is cut to facilitate the third-link mounting bar in question is 2"x8". The roll cage bar, as Mr. Tone notes, is forward of the mount and is correctly bent to stay within the rules.

 

If you need any additonal pictures or information , please let me know.

 

Bob Holmes

Posted
Thank you JWL. "This guy" would like to make it clear that the bar in question, which cuts through the floorplan is a mount for a third link. Regardless of the other characterizations, that is what it is for. The total area of the floorplan that is cut to facilitate the third-link mounting bar in question is 2"x8". The roll cage bar, as Mr. Tone notes, is forward of the mount and is correctly bent to stay within the rules.

 

If you need any additonal pictures or information , please let me know.

 

Bob Holmes

 

don't take any of this personally. I simply want to make sure that the rules are being enforced uniformly across the country. My issue with what you did is that I was told that it was illegal when I asked the question more than a year ago.

 

The reason being that the running the roll cage through the floorpan was too much like a tube frame car and they wanted to stay away from that 'grey' area.

 

If what you did is legal it opens the door for me to mount the roll cage through the floor for my lower control arms as it would then be functioning as a suspension mount as you will have set the precident for exactly that.

 

To reiterate, I am not taking issue with you simply the enforcement of the current rules and the rulings that have been made up to the is point in time. Though I do think that you could have designed the cage differently to accomidate your 6" of adjustment. By the way have you run any numbers on what happens to you geometry at either end of your adjustment range? I have never heard of or seen that much adjustment in a 3rd link without having some serious adjustment in the lower arms as well.

 

bpt

 

pm me your number if you want to discuss this further.

Posted

Bob-

 

The directors have had a chance to look at the pictures and read a bit about your setup and we are all in agreement that this is not legal under 7.3(g). The 2005 change to 7.3(g) was made specifically to limit what could be cut for third links as we realized this was a grey area in the 2004 and earlier rules. So, you can cut a hole through the pan, but it's got to be only for the purpose of passing the third link from the axle to the mount in the cockpit. From the looks of things, the floorpan has been cut to accomodate your mount in the cockpit and the cuts further back, while serving to let the third link into the mount, are also too much for what we intended with the rule. I'm very sorry for the pain in the ass that this is going to be to fix, but this problem proves the value of sending any ideas you have to us first before you start cutting and fabbing.

 

So, sorry for the bad news and let me know via PM if you would like to discuss further.

 

-JWL

Posted

John,

 

Is the preferred method for submitting "grey area" questions through an individual email or post it here?

Posted

Mark-

 

Either is fine. If it's something really noteworthy, I'll turn it into a tech bulletin so everyone is aware or I'm happy to post a reply in a thread. Your choice.

 

-JWL

Posted

Thank you for your attention to the issue. I guess its back to the shop; fire up the grinder and welder here we go again. Can I get the 2006 rules now?

 

Bob Holmes

Posted

Bob-

 

I have to agree with JWL and company on this one - I think they made the right call, but I wanted to give you a thumbs-up on your positive attitude after the decision. I know it sucks - that you have to go back and do this work - but I think you can understand why it's not good for the series.

Posted

Scott, can you post any pics of your 3rd link and how it comes up through the body?

 

Thanks.

Posted

Any help or pics on approved third links would be helpful. We may have been a little over the top on the adjustable portion of the front mount, which caused the need to sink it below the pan. We pushed the envelope, but you do that from time to time in racing. And I missed the 2005 update to that rule. Bummer.

 

I assume that I can just patch the floorpan. ?? I don't want to throw the whole thing away.

 

Bob

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