Dual Purpose Components

B

Bill Umstead

New member
I've looked in the GCR but did not delve too deep to see if this question is addressed...

Can a component serve two purposes and be compliant? Specifically, the IT rules allow for an engine stay-rod. The rule set also allows for a single suspension re-inforcement, e.g., a strut bar linking the top of the shock mounts on a MacPherson strut type suspension. Can the strut bar also serve as a locating device for the engine (i.e, an engine stay-rod)?

TIA.

Bill Umstead
 
Bill Umstead said:
Specifically, the IT rules allow for an engine stay-rod. The rule set also allows for a single suspension re-inforcement, e.g., a strut bar linking the top of the shock mounts on a MacPherson strut type suspension. Can the strut bar also serve as a locating device for the engine (i.e, an engine stay-rod)?
Click to expand...

Hmmm.... if you tie together the LH strut tower, the engine, and the RH strut tower, it could be argued that you have two engine stay-rods. You're only allowed one.
 
well my header is attached to my exhaust which is mounted in 3 places...

This might be worse than "extra" cage attachment points...


anyways...

2009 GCR 9.1.3.r. "One (1) engine stayrod may be added."

It seems obvious to me that said contraption would be legal and isn't even close to abusing the rule.

Heck, Based on that wording, it would seem that the door is left pretty wide open... Midplate anyone?! :eclipsee_steering:
 
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You guys better read the rules - and the glossary - again. And READ them, ignoring what you THINK or EXPECT or ASSUME they mean... just sayin'...
 
Greg Amy said:
You guys better read the rules - and the glossary - again. And READ them, ignoring what you THINK or EXPECT or ASSUME they mean... just sayin'...
Click to expand...

Well, for starters (and I think we've had this conversation before on these pages), the ITCS allows one "engine stayrod", which is not defined in the technical glossary. You can find, however, a definition for "engine steady bar" in that section of the GCR.

If we assume, just for the sake of discussion, the ITCS was really meant to allow an "engine steady bar", I would still say it could be argued that the proposed device (in the original post) would constitute two such bars.
 
Thanks for all the input into my question. The discussion thus far confirms my thinking on the question, i.e., that the rule set is not entirely clear.

I read the glossary definition for an "engine steady rod" to also define the engine stayrod term:

Engine Steady Bar (Torque suppressor) - A constraining beam or rod intended to resist the tendency of an engine to rotate on its mounts in reaction to torque forces.

From the Improved Touring Specs 9.1.3. 5(d) Suspension Mounting Points:

Cars may add one (1) front stayrod, located in one of the following areas:
A. Between lower suspensions mounting points.
B. Between the upper strut towers on Mac-Pherson strut equipped cars
C. Between upper front shock absorber mounts on cars with other forms of suspension.
I personally think the argument that a strut tower bar that is also used as a engine steady bar (stay-rod) constitutes two stay rods is a tortured reading of the regs, but having said that, I am not interested in installing one to find that it is illegal when a protest is issued or the scrutineers deem it unacceptable.

Bill Umstead



 
Look at what the GCR has offered:

Any engine stayrod - no glossary term that defines how this applies to a motor, only for suspensions.

One stayrod across the top of the shock towers - this is pretty clear

Since both items are allowed, one item can serve both functions. Based on this, tell me how you would lose a protest based on this: a single item across the top of the shock towers that picks up both shock towers, ONE point on the motor and as many places on the fire wall as you want.

Now tell me in the letter of the law how that is not legal? It is so tempting to build one just to see what would get said about it.

Look at the definition of a stayrod - it even offers up that it is to be mounted to "structurally significant locations"
 
.

Matt...I don't understand how you are able to jump to the firewall,
but I do agree that the connection to the engine is legal...try
looking at it this way.

Put aside the allowance for the "front" stayrod for a moment and
just design an "engine" stayrod.

From the glossary, a stayrod is "A rigid reinforcement bar or
rod interconnecting opposite sides of a car at structurally
significant locations"

Since there is no definition in the glossary of an "engine stayrod"
we have to make the totally reasonable assumption that an
"engine" stayrod, needs to be connected to the engine.

Since 9.3.D.1r says "One (1) engine stayrod may be added." it
is reasonable to say this means (1) attachment point to the engine.

So, you make one attachment point to the engine, and per the
glossary you interconnect opposite sides of the car at
structurally significant locations.

Now, for the sake of simplicity, let's choose the locations for
our new "engine" stayrod so they comply with the defined
locations for the allowed "front" stayrod.....viola, one bar two
allowed purposes!

-------

ok, now that I have hopefully convinced you that you can attach
the strut bar to the engine at one point, let me argue that
these pair of rules actually allow TWO front strut bars, one
that is attached to the engine, and one that is not....

would this be beneficial for stiffening? If you make the "front"
stayrod straight across the strut towers, and the "engine" stayrod
in a big V, attached to the towers, and a point on the aft end
of the engine block, it seems to make a nice triangular bar.

.
 
Matt...I don't understand how you are able to jump to the firewall,
but I do agree that the connection to the engine is legal...try
looking at it this way.
Click to expand...

Jeff - this jump comes from the lack of definition for how an engine stay rod is supposed to work. Allowing a transverse engine to hook to opposite sides of the car (left/right) is useless so is it safe to assume that the suspension stay rod definition is not in context here.

Allowing one engine stay rod w/o any definition on what that stay rod can or can't do makes it pretty free in my opinion.

I can run any muffler yes? Can I make it out of lead to add balast where I want it? Yes.

Is it pushing the rule a bit far? Hell yes. But I have not seen you leave much on the table when you drive the car so why would I expect you to do so when you build it?
 
Just because the stay rod is "useless" doesn't mean that it isn't a stay rod. Even if you mount the stay rod like you mentioned. where it has very little ability to resist movement.. (using bending and shear compared to a ideal compresssion and tension) it is still providding a resistive force.

"Jeff - this jump comes from the lack of definition for how an engine stay rod is supposed to work. Allowing a transverse engine to hook to opposite sides of the car (left/right) is useless so is it safe to assume that the suspension stay rod definition is not in context here."

as soon as torque is applied and the engine tries to rotate, this bar will be loaded, and as soon as it is loaded it turns into a engine stay rod.
 
So, let me get this straight..the ide is to use one bar that attaches from one shock tower to the other AND connects to the engine in the middle, as well as a rod that goes from the engine to the firewall?

Obviously this is to stiffen the chassis?

And the justification is that the allowed suspension stayrod may ALSO serve as the engine stayrod?

If so, how is adding a second one legal? Or is this for cars that already HAVE a stayrod from the firewall to the engine?
 
Sorry about that Glenn (and Jeff).

So, let me get this straight..the ide is to use one bar that attaches from one shock tower to the other AND connects to the engine in the middle, as well as a rod that goes from the engine to the firewall?
Click to expand...

No, one "bar" that picks up four locations - 2 shock towers, one motor, one firewall.

You can't tell me I'm the first one to think of this.
 
Yea, I've run that idea through my head for a few years, but I think my design would run afoul of the "one bar" terminology. My design left the poor engine out of it.
 
From the Improved Touring Specs 9.1.3. 5(d) Suspension Mounting Points:

Cars may add one (1) front stayrod, located in one of the following areas:
A. Between lower suspensions mounting points.
B. Between the upper strut towers on Mac-Pherson strut equipped cars
C. Between upper front shock absorber mounts on cars with other forms of suspension.
Click to expand...


Where does it say that this stay rod can attach to anything other than the places listed?

IIDSYCYC at it's finest.
 
Here's a blue sky idea. Due to the lack of detail on what a stay-rod is and how many bolts it can attach to, then why can't I call this a stay-rod?

chucker54_2058_2855588
 
I guess it is all in what you consider an attachment "point".. I had a similiar quesitno with the roll cage design, and what is considered a "point"
 
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