I have come across some Bellett GT-R specification lists that say the GT-R had power brakes. I think these are mostly the wikipedia and video game type references.

I seem to be specifically lacking in GT-R sales brochures.
And all of the Japanese magazine article and book stuff seems to either focus on the vehicle owner, or the DOHC engine. I haven't found anything mentioning brakes and the spec charts don't mention the topic.
The only thing I have seen is the multiple piston/reservoir master cylinders for the GT-R and 1800 cars.

As far as I know, there are only two ways to do power brakes. A vacuum booster has to go in between the firewall and the master cylinder, or a remote booster fed from the master cylinder and the brake lines go to the corners of the car from that point.
I have never seen a booster between the firewall and the master cylinder (and can't figure out how there would be clearance for one). And the multi piston master cylinders on the later cars would not work with a remote vacuum booster.

Is this an urban legend spawned by the video games?
Or do the GT-Rs have a vacuum booster stuck up under the dash on the back side of the firewall, with a vacuum line going through the firewall?

I vote 1 for Urban Legend...




OZ

They have a remote booster on the firewall above the exhaust manifold.

OK, that's going to be what this is. (picture below).

Is it set up with only the front brakes receiving power? It has separate reservoirs for front and rear, and piping. That would require two boosters, right?

Also, the rumorpedia quote:
"...the GT-R featured a 1.6 L DOHC engine from the 117 Coupe, power brakes and numerous other modifications."
The 117 Coupe has the booster mounted between the firewall/pedal and the master cylinder. So the power brakes weren't "from the 117 Coupe". The rumorpedia quote is ambiguous enough, but worded to at least imply the power brakes were a transplant, not a unique development.

This might be another thing to look for in identifying a GT-R. G161W engines might be pulled from 117 Coupes to convert Bellett GT's to GT-R "spec", but the remote vacuum booster might be more difficult to find.

all GT-R's had them, as did SOHC GT's, and alot of other jap cars from the day, so they are common enough and not a true guide of whether a car is a genuine GT-R or not tho.
i have one here to put in the "GT-R'd" orange sedan that looks exactly the same, but it's from a mazda 1500SS.

they only work on the front brakes.
the rears are plumbed direct from the master cylinder, and also have a proportioning valve under the back seat to prevent rear brake lock-ups.
the 35 page GT-R brochure i have here, printed in october 1969, shows an exploded view off all this in detail.