Back in the sixties Holden had been busy experimenting with quite a number of concepts such as fuel injection, over head cam-shafts and it was decided to design a Holden sports coupe on July 14th 1969. By December 15th the first body had been built which shows the effort and the outright determination of building a production lightweight sports coupe. After this the engineers started on the mechanicals which really had already been developed in the Torana which was developed on the track by Harry Firth and the boys. The Torana running gear seemed a perfect option and helped of course to drop the production costs which is why Holden developed the six cylinder race engine in the first place instead of continueing with the Chevrolet V8's and Monaro. There were certain criteria that this coupe had to meet if it was to become a production model and the most important was price! The Torana had the right ingredients in the suspension, transmission and engine departments. What Holden did with these restrictions was nothing short of brilliant and it was a great shame it never made it to the production line. The GTR-X was loaded with features like 4-wheel vacuum assisted disc brakes, retractable seat belts, foam filled fuel tank and electric windows to name a few. The GTR-X had to be sold for approximately 8 years to show a reasonable profit margin however to cover the tooling, production and design costs. The GTR-X came very close to going into production and the decision not to was most probably because of the release of the Datsun 240Z. The Datsun won the world over and the price was super competitive which showed in its sales, the 240Z became the biggest selling coupe in the world! Colour sales/info brochures on the GTR-X were even printed and handed out at various motor shows at the time. Opel may have had a contributing factor in the demise of the GTR-X as well because it was already selling it's own coupe and the parent company GMC were not sure the market could handle two low cost coupes as both Opel and Holden exported to the same countries then and still do today. The Opel was a very modest performer and the GTR-X would have been much closer in performance to the Corvette but it is now history and Holden was only allowed to build one coupe which was the Monaro as you couldn't really consider calling the two-door Torana a sports coupe.
I'm going to eat breakfast. And then I'm going to change the world.
Engine:
186 cid - 6 cylinder inline (3050 cc)
Bore and stroke:
3.625" (92.1 mm) x 3.00" (76.2 mm)
OHV with hydraulic lifters
single camshaft
9 port head
Triple 150CD carburettors
Transmission:
Four speed manual all synchro
Steering:
Reciculating ball with parallel linkage. Energy absorbing steering column with tilt mechanism. Steering wheel 14" diameter with fully padded rim.
Brakes:
Front: 10" (254mm) vacuam assisted discs
Rear: 9.75" (248mm) vacuam assisted discs
Handbrake: Self adjusting
Master Cylinder: Tandem with pressure differential and electrical warning system.
Suspension:
Front: Independent type short and long arm, coil spring.
Rear: Four link type, consisting of two longitudinal lower outer links incorporating mounts for coils springs and two diagonal inner upper links located for maximum lateral control. Rear shocks are mounted close to the wheels and forward of axle with increased stroke and modified valving.
Body:
Fibreglass
Seats:
Fibreglass "form-fitting" seat base. Adjuster handle pivoted on seat base. Molded foam pad fitted into seat base and trimmed with Sadlon material.
Seatbelts:
Lap and shoulder seat belts with self-adjusting locking retraction and fitted to roll bar
Rear Axle:
Ratio 3.36:1 with limited slip differential. Conventional propellor shaft of 2.75" diameter.
These figures were for the 160bhp motor but the intended engine was to be the 202ci which was still under developement. It is therefore an estimate that the 190bhp and 200 ft/lb torque larger engine and very light weight would have propelled the GTR-X to well over 140mph and would have quarter miled in the low 15's to high 14's. What about the 230bhp Bathurst engine?
Camshaft specifications:
Inlet (No ramp)
Open 29°
Close 57°
Duration 266°
Lift .345" (8.76mm)
Exhaust
Open 64°
Close 24°
Duration 266°
Lift .345" (8.76mm)
Overlap 53°
I'm going to eat breakfast. And then I'm going to change the world.
These figures were for the 160bhp motor but the intended engine was to be the 202ci which was still under developement. It is therefore an estimate that the 190bhp and 200 ft/lb torque larger engine and very light weight would have propelled the GTR-X to well over 140mph and would have quarter miled in the low 15's to high 14's. What about the 230bhp Bathurst engine?
The 230hp Bathurst 202 engines you refer to were a track-only development of the 1972 & '73 Torana GTR XU-1 Homologation Evolution road cars, aka 'Bathurst Specials'.
Specs: Weight 2310 lbs (1048 kg)
Cylinders Six in line, factory balanced and blue printed.
Bore & Stroke 3.625 inch x 3.250 inch (92.0 mm x 82.5 mm)
Cubic capacity 202 c.i.d. (3310 cc).
Compression ratio 10.8:1
Valves Overhead
Camshaft Single. Special "HX" race camshaft
Carburation 3 x 175 CD-2S (1.75 inch) (44.45 mm) Stromberg sidedraught. Flange increase to 1.860 inch (47.24 mm)
Fuel pump Mechanical
Power at RPM 190 bhp (141.6 Kw) at rear wheels. Approx.212 bhp (158.1 Kw) @ 6000 RPM.
Torque at RPM 200 lb/ft (271.5 Nm) @ 4000 RPM.
Max engine speed 6800 RPM
Maximum speed 138 MPH approx (222 KPH)
In gears speed:
1st 60 MPH @ 6800 RPM (96.5 KPH).
2nd 83 MPH @ 6800 RPM (133.5 KPH).
3rd 121 MPH @ 6800 RPM (194.7 KPH).
4th 138 MPH @ 6500 RPM (222 KPH).
Wheels & tyres 13 inch (330.2 mm) x 6.0 inch (212.4 mm) alloy rims, with 195/70 x 13 inch radial tyres.
Standing quarter mile elapsed time - 14.0 seconds.
Touring Racing Trim 230 bhp (171.5 Kw). Approx. 222 lb/ft (302 Nm) @ 5000RPM.
(Prod Touring Track Car 13.5 sec)
Tri-carb 6cyl Torana GTR XU-1s were a neat little car, I used to own a '71 186cid 'Bathurst LC' in Linamint. Attractive, affordable and very light. In their era a quick & compact road car with fantastic handling & brakes, and performance above contemporary 240Z, Capri V6, Lotus Escort, Alfa GTV etc.
Btw a 5-Litre V8 version of Torana XU-1 was proposed, using Holden's healthy 308cid, and the XU-2 model in fact gained production approval from Holden. But similar to the GTR-X it was cancelled at the last minute. Several prototype XU-2s were built. The envisaged 'production spec' version of XU-2 recorded 12.9 seconds on street tyres. Some were raced, including at Bathurst where a road-registered XU-2 achieved 272km/h (170mph) @ 7000rpm in 4th from only 271rwhp. XU-2s were to have a 164 litre petrol tank, yet dry weight was only 50lbs more than the six-cylinder XU-1 and weight distribution was improved.
Like many others I had a GTR-X brochure ex-Motor Show. Below are some pics from my hard drive of the surviving GTR-X proto from about 25 years ago, when it was resprayed in silver & wore Commodore SL/E mags, and as it appears today again in white after restoration. IIRC, GTR-X was chiefly styled by then-young Holden designer Phil Zmood. Along with the 'boomerang' tail lights (upended Torana units) a unique style-signature of GTR-X was its funky reverse-kink A pillar
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Originally Posted by Matt
