Rules Question Summary

2015

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1/2015

Question

We've noticed that CAMS now requires many forms of motorsport to use frontal head restraint (HANS) devices, and we'd like to clarify whether or not that will be a requirement for Formula SAE as well, as it would represent a fairly large expenditure to procure the restraints, new seat belts etc • • • •

Answer

CAMS show same as prior years that Frontal Head restraint is “B” for Speed Events which is recommended but not required. FSAE 2015 Rules are as in previous years and do not require it, nor recommend it.

It has not been proposed at all for Formula even in future years. I think our event speeds and circumstances minimise any need.

We also require arm restraints of course which are not mentioned at all in the CAMS requirements.

I think our position should/would thus be that our required equipment standards stay as in prior years and we do not require (or recommend) such devices.

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3/2015

Question

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T3.40.3

Each attachment point requires a minimum of two (2) 8 mm Metric Grade 8.8 (5/16 inch SAE Grade 5) bolts

• Does this rule only refer to attaching primary structures to the monocoque (e.g. the rear sub frame) or does it include wishbone pickups and suspension mounting points?

Answer

The rules T3.40.3 specifically relates to the attachment of other parts of the Primary Structure to a monocoque shell. Other attachment points are not required to conform to this mounting design but should be designed to meet the anticipated loads and strength of the monocoque and installed using sound engineering practice.

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4/2015

Question

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T7.1.9

Brake Pedal must be fabricated from steel or aluminium or machined from steel, aluminium or titanium

Specifically, we are asking as to whether the brake pedal can be 3D printed by titanium (Arcam titanium 6-4) and then post machined. In the Electron Beam Melting (EBM) process, dense metal components are built up, layer-by-layer of metal powder and melted by a powerful electron beam. Each layer is melted to the exact geometry defined by a CAD model.

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Answer

The rules specifically only allow pedals fabricated from Aluminium or Steel, with Titanium accepted only if machined from solid stock. Your deposited design is thus not acceptable.

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5/2015

Question

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T9.2.2

When viewed from the front of the vehicle, the part of the front wheels/tires that are more than 250 mm (9.8 inches) above ground level must be unobstructed by any part of the aerodynamic device, with the exception of any vertical surfaces (end plates) less than 25 mm in thickness.

• What is acceptable as an endplate in the region of the tyre from the top to a plane running 250mm from the top surface? Please see pictures below

Answer

The intent of the rule is to not allow a greater than 25 mm lateral width of vision obscuration in front of the tyre. Your first design would appear to significantly exceed this whereas the second design is in line with the intent of the rule for a simple flat endplate running parallel to the vehicle centreline, provided the maximum thickness at any point does not block more than 25 mm width of the tyre.

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7/2015

Question

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T10.2

"The driver and anyone standing outside the car must be shielded from any hydraulic pumps and lines"

• If the body of the chassis (carbon skins with nomex core) separates the line and driver, would this still require an additional 1mm metal shield?

Answer

Provided that the lines are fully shielded (i.e no openings that may allow impact) from both the driver and any external bystander by the structural material you describe, a separate shield per T10.2 Is not required.

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9/2015

Question

EV 3.3.3

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Maintenance plugs, additional contactors or similar measures have to be taken to allow electrical separation of the internal cell segments such that the separated cell segments contain a maximum static voltage of less than 120VDC and a maximum energy of 6MJ. The separation must affect both poles of the segment.

• • •

Answer

The calculation of Energy Stack per EV3.4.11 is derived from

maximum static voltage per module = # of cells x Max Voltage per cell.

maximum energy per module = # of cells x Rated Capacity x Max Voltage per cell x 3600 J/Wh.

• • From your 2014 data the limit of 6.8MJ would be exceeded.

EV 3.4.11

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The accumulator segments contained within the accumulator must be separated by an electrically insulating and be fire resistant barrier (according to UL94-V0, FAR25 or equivalent) and must subdivide the accumulator into 6MJ segments if this is not already met by the separation due to the 120VDC voltage limit.

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NOTE: The contained energy of a stack is calculated by multiplying the maximum stack voltage with the nominal capacity of the used cell(s). Documentation of segment separation must be provided in the ESF.

• • • We are, however, for 2015 only, willing to allow the use of

the nominal voltage for the energy calculation only.

(Maximum Voltage must still be used in the Maximum Voltage per module calculation).

The separation of the subsequent segments to meet the 6MJ limit must be created by use of maintenance plugs or similar contacts

which can be disconnected without the use of tools.

We are uncertain as to how the energy stack is calculated; can you please provide the formula used for this calculation?

This segmentation into 6MJ will require repackaging of our 2014 battery package, as we believe we exceed this maximum allowable energy limit. Our batteries were purchased and packaged last year before these rules were released, and we intended to utilise these batteries for two years given the significant cost of batteries. In order to comply to this rule change, we would have to disassemble the current battery packs and repackage them but we are concerned about the strength of the cell tabs due to heat cycling. Repackaging the battery cells to meet this rule amendment could be more dangerous than to leave the battery packaging in its current state, which we believe to be around 7MJ.

• • •

10/2015

Question

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IC4.6

It was not the intention of the rules committee to introduce more restrictive voltage limits within the IC category which prevents the use of OEM 12V charging systems. If the charging system is OEM and designed for a DC battery voltage less than 60V then the 25VAC limit of rule IC4.6 does not apply, however the system must either use the stock wiring between the generator and the rectifier, or this wiring must be rated to at least the maximum output voltage of the rectifier. If student teams are electing to build a charging system then rules must be followed.

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Answer

The approach you propose is acceptable provided that appropriately rated connector/plug is used and the OE, or appropriately rated, wiring is used.

We would like to replace the stock regulator/rectifier with an aftermarket unit. To be clear, the replacement unit will not be constructed by students. For the benefit of the committee, this is the link to the product we are considering: http://www.ebay.com.au/itm/Compu-Fire-55402 Regulator-for-40A-3-Phase-Charging-Systems-60 3337-/331114765797 In our case the wiring would remain stock with the connector being replaced with an appropriately rated plug. In this way we believe the replacement would comply with the intention of the rules (safe charging system) especially as it is not uncommon for teams to substitute OEM regulators with units from similar bikes.

11/2015

Question

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IC3.2.1

The sound level will be measured during a static test. Measurements will be made with a free-field microphone placed free from obstructions at the exhaust outlet level, 0.5 m (19.68 inches) from the end of the exhaust outlet, at an angle of forty-five degrees (45 °) with the outlet in the horizontal plane. The test will be run with the gearbox in neutral at the engine speed defined below. Where more than one exhaust outlet is present, the test will be repeated for each exhaust and the highest reading will be used.

In the case of dual exhaust outlets, does the committee intend for four test locations in total?

We would argue that considering each outlet in isolation and testing accordingly may result in the microphone becoming too proximate to the other outlet. In an exhaust arrangement as described, would only the two outboard test locations be considered?

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Answer

To focus on only the outboard location would not meet the wording of the rules and in fact the inner location may be louder (by chance, or by design) than the outer. Accordingly you should assume that the Scrutineers will measure at 4 locations for dual exhaust systems. The maximum measurement of these will be the one recorded, irrespective of potential interference from other outlets.

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12/2015

Question

Can we attach the seatbelt attaching eye bolts by welding?

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Answer

No. Refer

T5.2.2

for minimum mounting bracket requirements