Seat Cross Member

[goldleaf]

I am building a gas roadster.  While reading the rule book under 3.E Driver's Compartment, it states:

 "A cross member running below the driver's body, no smaller that the roll bar applicable to the class, shall protect any portion of the driver's body that extends below the main frame rail."

Even though the driver's body is above the main frame rail, does it have it have to have the same size and wall thickness as the roll cage?  The roll cage is funny car style with a fiberglass seat.  the driver position is in the center of the car and the drive shaft is directly under the seat.  Right now I have some smaller tubes and straps under the seat.

Will this pass tech? 

Francis 

[Bob Drury]

Francis, I will let Dan or J.D. answer this one, but  if you check out the catalogs for Chris Alston Chassisworks, Art Morrison, or several other chassis shops, they make a plate type hoop that can be attached to square tubing  that allows the crossmember to intersect the drive shaft.  Remember, you can exit thru the bottom of the car in a crash as easily as the top, so build it as strong as the cage.

[Glen]

Post some pictures for us to look at,makes life easier to answer questions
Glen

[SPARKY]

Some inspectors "may" take issue with a fiberglass seat.

[jimmy six]

Gold, welcome, First no fiberglass seats. Answer to what supports the seat. Thickness and diameter should be the same as the cage material. You did not say the position of the seat in the car. That may have some bearing on how you construct the place you will sit. I sit over the drive shaft and the seat bottom is 1/4" plate steel. If you sit next to it you need to cover the entire length of it. Plus build a place to sit.

Take the time to look at many different roadsters to see how you want yours to look and be constructed. Today builders seem to build them for 300 mph no matter what engine will be used. Good idea for resale. All different styles of frames are used. Multitube are the hardest to make fit due to the step pan and floorboard designations. The definitions are in the book and need to be followed. Good Luck

[goldleaf]

Thanks Sparky & Jimmy 6 for your comments on the seat and cross members.  I was not aware that fiberglass was not a good choice for the seat as I did not see any indication in the rule book that fiberglass was not acceptable. 

Jimmy 6, my roadster is similar to yours as I also sit on the centerline over the drive shaft like yours.
I'll put some large tubing under the seat.

Thanks a lot.  This is why this site is worth a million dollars to us amatures!  Without your knowledge we would have 10,000 miles on the trailer and never get to race.


Francis


 

[interested bystander]

Wuz gonna comment on the flippant reply "no fibreglass seats". I also, have seen that NOWHERE in the rule book (SCTA-BNI 2006).

There is/was some regulation on PLASTIC seats in certain racing associations- understandable, but it's a fact that a decently laid up fibreglass seat properly installed to satsify the rules and tech people, would perhaps have some safety advantages over an .050" aluminum seat, for instance.

How bout your two cents-worth 1212?

[sockjohn]

Wuz gonna comment on the flippant reply "no fibreglass seats". I also, have seen that NOWHERE in the rule book (SCTA-BNI 2006).

There is/was some regulation on PLASTIC seats in certain racing associations- understandable, but it's a fact that a decently laid up fibreglass seat properly installed to satsify the rules and tech people, would perhaps have some safety advantages over an .050" aluminum seat, for instance.

How bout your two cents-worth 1212?

I think it's in the changes for 2007.

Considering how well fiberglass burns, I wouldn't want to be strapped to it!  Maybe I'm just paranoid.

[JackD]

Wuz gonna comment on the flippant reply "no fibreglass seats". I also, have seen that NOWHERE in the rule book (SCTA-BNI 2006).

There is/was some regulation on PLASTIC seats in certain racing associations- understandable, but it's a fact that a decently laid up fibreglass seat properly installed to satisfy the rules and tech people, would perhaps have some safety advantages over an .050" aluminum seat, for instance.



How bout your two cents-worth 1212?

I think it's in the changes for 2007.

Considering how well fiberglass burns, I wouldn't want to be strapped to it!  Maybe I'm just paranoid.

That would sorta eliminate the use of a fibreglass helmet , canopy, belts, and complete body skin, just to name a few.
An ill fitted/weak seat of any material I think would be a worse hazard.
Are we jumping in the pool without checking for water ?

[sockjohn]

Wuz gonna comment on the flippant reply "no fibreglass seats". I also, have seen that NOWHERE in the rule book (SCTA-BNI 2006).

There is/was some regulation on PLASTIC seats in certain racing associations- understandable, but it's a fact that a decently laid up fibreglass seat properly installed to satisfy the rules and tech people, would perhaps have some safety advantages over an .050" aluminum seat, for instance.



How bout your two cents-worth 1212?

I think it's in the changes for 2007.

Considering how well fiberglass burns, I wouldn't want to be strapped to it!  Maybe I'm just paranoid.

That would sorta eliminate the use of a fibreglass helmet , canopy, belts, and complete body skin, just to name a few.
An ill fitted/weak seat of any material I think would be a worse hazard.
Are we jumping in the pool without checking for water ?

Helmet, canopy, and belts don't have a non-flammable substitute though.  The seat and body skin does, so why take chances?

I was actually not expecting to see so many fiberglass body's when I started looking at land speed racing.  The stuff is smelly, sticky, and a pain to work with anyway, besides burning.  Metal work can be slow going and hard to get compound curves, so I understand why people use fiberglass.  Personally I wouldn't, but everyone is free to build their car/bike as they sit fit within the rules.  Like I said, probably just me being paranoid.

Anyone ever confirm if this is indeed a rule for 2007, no fiberglass seats?

[Seldom Seen Slim]

From the 2007 rulebook:
"3.D.1   Seats:
All vehicles should use a seat designed for racing. The seat shall be made of a metal, alloy or composite material (no ?plastic? seats will be allowed beginning January 1, 2008). The seat shall be securely fastened with a maximum of 1? padding. Sprung or compressible seats are prohibited. Seats shall be securely installed and braced to prevent rearward collapse."

[JackD]

Many cars are all fibreglass on the entire body.
As the belt system goes through or around the seat to the mounting, what do you think will yield to a fire first ?
Canopies that are fibreglass do have a substitute if they are a fire hazard and it is metal.
I think the rule was directed at injection moulded single layer plastic seats that will lose strength and shape long before they will sustain combustion.
The seat material rule might be more specific before it gets into the book.

[dwarner]

Jack is correct, plastic seats such as found in the the 1-800 books are the target.

Does anyone know what a roto- moulded product is?

DW

[1212FBGS]

DW
a roto-molded seat is exactly that... it is a seat made by rotating the mold. Roto molding is commonly found in the plastics industry. the process starts by heating a aluminum mold and injecting plastic pellets (usually low melting plastics like polyethylene) into it, as the pellets melt, the mold is rotated to coat the inside of the tool, when the mold is thoroughly coated the heat is removed and the plastic starts to harden while the mold is still being rotated. After the plastic cools or "B" stages the part is released from the tool and hopefully sales are good enough to start the process all over again. Roto molded products are a cheep way to make a hollow cavity part without the expence of an internal core. Common roto molded parts beside seats are, kayaks, Jazz style fuel cells, trash cans, even some ceramic figurine's.
Composite seats including fiberglass and carbon fiber are still legal. well made composite seats will hold up to stresses, and vibration much better than aluminum! Have you ever seen an aluminum seat all cracked up around the mounts? Check yours it might be. That's why Kirky and other manufacturers triple reinforce all there alum seats in the mounting areas, they know they are prone to failure. My liner seats are all carbon fiber.
The question is about the tubing structure below the driver, not whether anyone thinks this seat is better than that seat or what might not be legal next year. Consider the seat like the hood of your car.... you can drive your car with out the hood... you should be able to drive your race car without the cosmetic seat! the cage should be tight around the driver and the safety harness designed so you ARE NOT relying on the seat for restraint. You should be able to set in the frame and harness and drive the vehicle without a seat. Last weekend Rick Vesco dropped off Don's bike liner the "Lightning bolt", Don Vesco raced and crashed this liner several times over 300mph.....That liner didn't have a seat.... never did..... and when we restore it....it never will.
Kent

[JackD]

I Do , I DO !
But more important Dan and Kent  DO.
I knew when I brought Kent to the races for the first time in 84, he showed promise.
There are plastic, hollow core, moulded racing seats that are very well suited for our use.

There are single layer seats with the same chemical make up that are only suited to use on the lawn if you don't exceed the maximum weight.
You can get them for under $10 at the grocery store.
I can get you the special ones for Bonneville that won't rust for $20 each plus shipping.
We can even rent them to you for $5 a day if you are traveling light.  LOL