Interpretation ID: nht94-3.73
TYPE: INTERPRETATION-NHTSA
DATE: July 18, 1994
FROM: Federico Trombi -- Chief Homologation Engineer, Bugatti Automobiles
TO: Taylor Vinson, Esq. -- Office of the Chief Counsel, NHTSA
TITLE: Additional Request for Interpretation of FMVSS 108
ATTACHMT: Attached to letter dated 7/28/94 from John Womack to Lance Tunick (Std. 108)
TEXT: Dear Mr. Vinson:
This letter requests an additional opinion from NHTSA as to whether a second anticipated version of the Bugatti EB 110 headlamp would be in compliance with Federal Motor Vehicle Safety Standard (FMVSS) 108.
This letter is in addition to the Bugatti interpretation request of July 8, 1994, and it is not in lieu thereof. We therefore request that NHTSA respond to both requests. However, we ask that NHTSA not delay the response to either this or the July 8 request because a response to the other may not be ready. Thus, when a response to one is ready, kindly provide it to us, without waiting for the other to be completed. Thereafter, when the other response is prepared, please provide it in a separate l etter. Thank you.
The second version of the proposed Bugatti headlighting system, that is the subject of this letter, would consist of two headlamps. In each headlamp:
The low beam would be provided by a gas discharge unit; and
The high beam would be provided by one "irreplaceable bulb" unit, or such unit together with the gas discharge unit. (In the alternative, instead of an "irreplaceable bulb unit, Bugatti may use a second gas discharge unit.)
The headlamp "box" would be an indivisible entity that would be treated as an exchange unit, and all internal screws would be sealed to prevent removal. The gas discharge unit's bulb, receptacle, reflector, ballast, etc. would be an indivisible unit. The "irreplaceable bulb" unit would be a replaceable bulb unit with an H-1 bulb of approximately 100 watts and the unit would be modified so that the bulb is NOT replaceable. All problems with
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the headlamp box would therefore be remedied by the replacement of the entire box, which can then be remanufactured at the factory.
As described above, the headlamp would be an integral beam headlighting system provided for in FMVSS 108, S7.4. More specifically, the Bugatti integral beam headlighting system would be comprised of two headlamps that comply with S7.4 (a)(2) and the photometric requirements of either (a)(2)(i) or (a)(2)(ii).
The Bugatti headlamp would have the low beam gas discharge unit mounted towards the center of the box (as in the diagram provided to NHTSA) and the "irreplaceable bulb unit" would be mounted inboard of the gas discharge unit.
Outboard of the low beam gas discharge unit, Bugatti may install either a replaceable bulb fog lamp or driving lamp that is not regulated under FMVSS 108.
Bugatti believes that the above headlighting arrangement is permissible under FMVSS 108. Table IV requires that the low beams be mounted "as far apart as practicable". The reason that the gas discharge unit cannot be mounted any farther outboard tha n as proposed is that, because of the design of the Bugatti EB110 body, there simply is not sufficient room (Bugatti's previously submitted attachment shows that if the gas discharge unit were mounted further outboard, it would conflict with the wheel ar ch).
Moreover, the headlamp would be in conformity with S7.4(b) as the lamp would have 2 light sources and the lower beam would be provided by the most outboard light source (as far as FMVSS 108 is concerned -- the fog or driving lamp would be disregarded) , and the upper beam would be provided by either the most inboard light source or both the gas discharge and irreplaceable bulb light sources.
Is the above-described headlighting system permissible?
We urgently need as swift a response as possible in order to proceed with production. Kindly contact the following with any questions and the response:
Mr. Lance Tunick
1919 Mt. Zion Drive
Golden CO 80401
tel. 303 279 0203
fax 303 279 9339
Thank you.