Nathan's Road-Legal/Track BB4

[NafemanNathan]

I did think about that actually, but not going to bother with that for now

[NafemanNathan]

Actually, do you have to have two high beams? Of course if it's there it needs to work, but if it isn't?...

[indigolemon]

i like the idea, i really do, maybe a duel filament bulb could be fitted into the dipped beam side?

The standard h4 is already dual filament. You could likely create a wee patch lead to supply 12v when the high beam goes live to the third pin. Couple of inches of wire and a spade connector should do it?

[4thgenphil]

graham is right u know!

i was think of wiring it up so both would come on but was worried about melting wires!

[Gayno]

MOT Section 1.7.3 states:

Check that the vehicle is securely fitted with obligatory headlamps, as follows:

. a matched pair of main beam headlamps, and

. a matched pair of dipped-beam headlamps

Note: Main and dipped-beam functions may be provided by a single pair of headlamps.

So yes, you MUST have high beam

[indigolemon]

Matched pair, I assume you could do the same on the other side and find another use for the high beam space?

[Gayno]

This is true.

The only problem I can see arising from this is I think the main distinguishing feature between dipped and main beam are they use different reflectors, so just sticking a brighter bulb into th dipped beam reflector may not work. Also, H4 bulbs are designed to turn off the dipped filament when the full filament comes on. Having both on will likely overheat and burn the bulb out rather quickkly.

[indigolemon]

I would assume they'd be used for MOT purposes only really. And single light is fine, most older cars only had one round headlight per side

[Gayno]

I would assume they'd be used for MOT purposes only really. And single light is fine, most older cars only had one round headlight per side

Yes, but the internal reflectors were designed for this.

On the Prelude each beam has it's own reflector design.

[NafemanNathan]

MOT Section 1.7.3 states:

Check that the vehicle is securely fitted with obligatory headlamps, as follows:

. a matched pair of main beam headlamps, and

. a matched pair of dipped-beam headlamps

Note: Main and dipped-beam functions may be provided by a single pair of headlamps.

So yes, you MUST have high beam

Are they calling high beam "main beam"?
I'm getting confused I think from my old Escort days where everything was behind one lense. I used to think it was dipped beam, main beam and high beam. Was it in fact side lights, dipped beam (normal beam) and main beam (blinding)?