Tranny undertray

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Tranny undertray

Postby FV90 » October 3rd, 2017, 1:28 pm

Due to some inserts being "uninserted" I have neglected to reinstall my tranny/engine undertray. My local tech inspector says this is illegal. After reading back over the GCR I can see his point.
So after looking at a few vees I do see some without those trays (of course they have bellypans) in the engine/tranny area. So is this a big deal? I would tend to think the rc would run cooler and not as slick but has someone had paper thrown at it for this?
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Re: Tranny undertray

Postby BLS » October 3rd, 2017, 10:06 pm

I am unable to find any rule requiring an undertray below the engine or transmission, only rules regulating the undertray if used.
Barry
Old Zink FV,
'87 Citation
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Re: Tranny undertray

Postby CitationFV21 » October 3rd, 2017, 10:28 pm

Yes - we have some confusion here.

Is this for SCCA racing or Hill Climb?

From the GCR:

8. Frame
A. The frame/chassis shall be constructed of steel tubing of a maximum
diameter or width of 4 inches and be of a safe and suitable design.
B. The driver’s feet shall not extend beyond the rear of the front axle
beam tubes.
C. There shall not be frame/chassis rigidity or strength derived by
means other than the frame tubes. Stressed skin, monocoque, or
semi monocoque construction is not permitted, except that:
The firewall panel and undertray(s) may be rigidly attached to the
frame tubes.
D. The undertray (belly pan) from the nose to the rear roll hoop shall
not be wider than the bodywork at the bottom of the frame rail
or no more than 1/4 inch wider (on each side) than the frame rail
when the undertray has an upward turned edge that facilitates
mounting the undertray to the chassis or that facilitates mounting
the body to the chassis.
E. Engine bay undertrays shall be no wider than the frame rails in this
area or no more than 1/4 inch wider (on each side) than the frame
rail when the undertray has an upward turned edge that facilitates
mounting the undertray to the chassis or that facilitates mounting
the body to the chassis.
F. Any undertray(s) between the axle center lines shall be rigidly
attached to the frame provided the curvature of said tray(s),
measured vertically from the lowest point to the highest point at
their attachments to the frame rail members at their sides, shall not
exceed 1 inch and have no downward turned edges.

Words to look for are "THE" "SHALL" "MUST". The fact that E says engine bay undertray[u]s[/u] does not require an undertray, just that if you have them they must meet these rules. As written, you do not even have to have a bellypan (floor) or that it can be held on by something other than rivets. You might take "The" as we expect you to have it, but since they don't even require that it be a stressed member (although we all agree it is better) it could be fiberglass or wood bolted to the bottom of the car

The "shall be rigidly attached" in F means you cannot have a movable structure - again if you have it. No diffusers

So the sort answer is that you do not HAVE to have an engine undertray and most of us do not run one.

ChrisZ
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Re: Tranny undertray

Postby FV90 » October 4th, 2017, 8:06 am

This is a RR Vee, SEDIV TT for the hillclimbs will use the current GCR.
This individual has been around for years but has seemed to make this an item.
I agree with the above posts
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