rule question about sub-frame in SP

[nhsilversti]

for SP it states 100% of the stock sub-frame must be used. does this mean it can be added to for strength? also on the subaru there is a really 2 "sub-frames" on the front, one that hold the motor/steering rack/controll arms and another that bolts to the one just mentioned as well as the uni-body and is shaped like a U.

would the 2nd "sub-frame" be considered more of a brace and could be replaced/removed/added to?

i am looking at aftermarket parts that are stronger and will have provisions for splitter attachment.


ted

[Stynger]

Street Prepared automobiles must comply with section VI, then any modifications are permitted while observing the following restrictions:

7. 100% of stock frame or sub-frames must be retained.

Doesn't say you can't add.

It does say sub-frames must be retained.

Is it a sub-frame, or a brace? Sounds like a brace to me.
A subframe would hold the suspension points, engine etc.

Can you take this brace off the car and still have the sub-frame connected to the unibody?

[nhsilversti]

you could remove this U shaped piece and drive the car with issue. here is where the problem lies, it is known as a sub-frame but, is it really......it ties the real sub-frame and the uni-body together.

i like the thinking that it is a "brace" but there is still the "s" at the end of frames.

[ctkag]

The 'U' is a subframe brace. No part of the suspension actually bolts to the 'U', its purpose is to reinforce the existing subframe. There are a multitude of replacement subframe braces for that 'U' piece.

[zip4zat]

I thought that U brace was for crash/impact force distribution.. not for much structural support

[WillM]

Without seeing the parts, sounds like it is a subframe brace.

Interesting question though. The rule in question states:

7. 100% of stock frame or sub-frames must be retained.

As Les pointed out, if you add bracing to the subframe, do you still have a stock subframe, or is it now non-stock? If you haven't cut anything away from the subframe, isn't it still stock, and couldn't whatever you added be considered a brace?

Also, what if you move the subframe? It is still stock?

Since it is not spelled out in the rulebook anywhere, this would be my take:

Showroom Stock & Street Touring:
Bracing as allowed in the rulebook must be bolt-on, no welding.

Street Prepared & Prepared
Bracing as allowed in the rulebook can be either bolt-on or welded. For a component to remain stock, it can not have any of its structure removed or repositioned (ie: bent). Mounting points on the part must remain stock and cannot be relocated. Bracing may be bolted on or welded. Holes may be drilled only when used to pass bolts through to secure additional bracing. No allowed modification which would alter the stock function, configuration, or geometry is permitted.

[Stynger]

Since it is not spelled out in the rulebook anywhere, this would be my take:

Showroom Stock & Street Touring:
Bracing as allowed in the rulebook must be bolt-on, no welding.

Street Prepared & Prepared
Bracing as allowed in the rulebook can be either bolt-on or welded. For a component to remain stock, it can not have any of its structure removed or repositioned (ie: bent). Mounting points on the part must remain stock and cannot be relocated. Bracing may be bolted on or welded. Holes may be drilled only when used to pass bolts through to secure additional bracing. No allowed modification which would alter the stock function, configuration, or geometry is permitted.

I'd go along with that except I'm not sure it pertains to Prepared where nothing needs to be stock.

[dinoracer]

The rule in question states:

7. 100% of stock frame or sub-frames must be retained.

Since it is not spelled out in the rulebook anywhere, this would be my take:

Street Prepared & Prepared
Bracing as allowed in the rulebook can be either bolt-on or welded. For a component to remain stock, it can not have any of its structure removed or repositioned (ie: bent). Mounting points on the part must remain stock and cannot be relocated. Bracing may be bolted on or welded. Holes may be drilled only when used to pass bolts through to secure additional bracing. No allowed modification which would alter the stock function, configuration, or geometry is permitted.

I think that's adding excessively to the rule's original intent. I think this rule was created with "stone age" cars (60s-70s) in mind and intended to restrict car owners from removing the stock flimsy uni-body sections on cars of this era (like mine) where front or rear suspension mounted, and replacing it with NASCAR-like "stub-frames", and associated suspension systems. This kind of work would be a lot of cutting, fabrication and welding beyond the "spirit" of SP classes.

I think at the time the rule was written, replacement sub-frames or engine cradles with suspension mounts weren't that common. I'd be in favor of allowing aftermarket subframes in SP classes, as long as they are bolt-in swaps - no cutting and welding. I think to take full advantage of aftermarket upgraded suspensions, as allowed in SP, in most cases you need a different subframe to relocate certain mounting points.

Also, I don't see the current rule as restricting relocation of mounting points for suspension components on the frame or unit-body, and wouldn't support adding that restriction in SP classes.

[jlwhorf]

The rule in question states:

7. 100% of stock frame or sub-frames must be retained.

Since it is not spelled out in the rulebook anywhere, this would be my take:

Street Prepared & Prepared
Bracing as allowed in the rulebook can be either bolt-on or welded. For a component to remain stock, it can not have any of its structure removed or repositioned (ie: bent). Mounting points on the part must remain stock and cannot be relocated. Bracing may be bolted on or welded. Holes may be drilled only when used to pass bolts through to secure additional bracing. No allowed modification which would alter the stock function, configuration, or geometry is permitted.

I think that's adding excessively to the rule's original intent. I think this rule was created with "stone age" cars (60s-70s) in mind and intended to restrict car owners from removing the stock flimsy uni-body sections on cars of this era (like mine) where front or rear suspension mounted, and replacing it with NASCAR-like "stub-frames", and associated suspension systems. This kind of work would be a lot of cutting, fabrication and welding beyond the "spirit" of SP classes.

I think at the time the rule was written, replacement sub-frames or engine cradles with suspension mounts weren't that common. I'd be in favor of allowing aftermarket subframes in SP classes, as long as they are bolt-in swaps - no cutting and welding. I think to take full advantage of aftermarket upgraded suspensions, as allowed in SP, in most cases you need a different subframe to relocate certain mounting points.

Also, I don't see the current rule as restricting relocation of mounting points for suspension components on the frame or unit-body, and wouldn't support adding that restriction in SP classes.

Eventhough I don't run in SP, I agree with everything Tom says. Especially when SP allows kit cars, which are for the most part, thinly disguised race cars. With the current slurry of aftermart goodies, the rule should be if you can bolt it to the stock tub, it should be legal. Other wise the rule book would need to maintain a list of legal, subsystem components.

Jonathan