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Rokstock RSR Turbo

17632 Views 55 Replies 14 Participants Last post by  supraz
For anyone who grew up in the 70s and read Road and Track magazine you probably knew about the Rokstock. I like to think that this is the 1970s version of the Celica Supra. A reasonable cost 2 door hatchback with 6-cylinder that was easy to upgrade for more performance.

Richard O. Kiser formed a tuner company Rokstock in Tigard Oregon that sold performance parts for the Mercury Capri II. He sold everything from cosmetic parts such as front spoiler, rear whale tail, suspension parts from mono-leaf rear springs and Bilstein shocks, engine upgrade kits, up to converting your Capri into a full RSR Turbo.

He used an Ak Miller draw-through turbo to significantly increase the hp over that of the stock engine. The Ak Miller system used an AiResearch turbo running at 7psi of boost to deliver 175-180 hp. The base engine was a stock 2.8L V6. 9psi boost was also available.

The typical Rokstock suspension lowered the car 2 inches and one of the wheels sold were Cromodora 'Daytona' magnesium wheels in 13 x 6 1/2". These wheels weighed about 9.5 pounds!

13 x 6" version of the Cromodora 'Daytona' magnesium wheel

You could purchase any of the above parts or if you had Rokstock convert your Capri you were given a Rokstock serial number. Apparently only about 35 RSRs were ever built.

It sounds like he ran into financial problems and withdrew from the automotive scene which has increased the mystique of the car.

It was quite well sorted. Road & Track magazine wrote an article on the car so there IS some information about the cars.

What sounds like a partial conversion car surfaced in Calgary Alberta, and passed through several hands. I don't know if there are any other of these cars still in existence.

There is a Capri list which is quite quiet compared to the Celica Supra forum. I think there are a few others here who are members of the Capri list as well.

If anyone has information on other Rokstocks, I would love to hear about them.

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My brother has one of those Ford Capri 2's, the engines factory are actually capable of quite a bit of power, but that was not good enough for the drag racing he planned for it; so the rear axel was remove in favor of a Toyota Hilux 2WD rear 31 spline out of a 3/4 or 1-ton variant of that model truck (they can be ID'd by the long bolt that runs up under the pinion and they are very rare)

Transmission was replaced by a manually shifted C4 with the line pressure turned up to atomic, and the shifting servo's replaced with some custom built units to handle the absurd line pressure.

Engine was replaced by a 89 5.0 Ford roller motor, ported and port matched for the smooth running characteristic that you would hope for, this motor came with an aggressive state of tune (factory ECU), and factory supplied forged pistons only present in the 5.0 mustang cars, and no other models.

All "power" accessories were removed in favor of light weight, to be made as minimalist / functional as possible.

That car is fairly impressive pushing conservative ~12.9 second quarter mile times with only 210 wheel horsepower, due to its ultra light weight and surprisingly low drag. I recall him putting it on the scale once @ 2300LBS, its shockingly light.

A few things you really wanted to watch out for on these cars was the factory brakes and suspension were made of jelly, but with proper upgrades these cars could be incredible compared to modern cars simply because the weight distribution was good, and they don't weigh anything stock; a real fat one from the factory only weighs in at 2600.
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