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Top Flight Citroens

By Stuart Bladon

Injection and five-speed gearbox provide the missing punch for CX

Autocar 14th May 1977

SOME TIME ago it was known that CitroŽn planned a new model introduction this month, and it was interesting to speculate whether this meant the long-rumoured arrival of the V6, 2.6-litre engine, which is built in France for Peugeot - Renault -_ Volvo, as a new power unit for the CX. In the event, it is nothing so radical; but this is no cause for disappointment. The new model, called the CitroŽn CX2400 GTi, offers really good performance - at least a match for the Renault 30TS - and is almost its equal in terms of smoothness.
Bosch L-Jetronic fuel injection is used in the GT for the larger of the two petrol engines (the 2200 is now available only as a diesel). Compared with the former, carburettor 2400 engine, which continues in production, the new injection version offers 13 bhp more, with a new peak of 128 bhp. Maximum power is developed appreciably lower in the rev range - at 4,800 rpm instead of 5,500 - and there is a useful gain in torque. Maximum value is 145 lb. ft. against the Carburettor engine’s 132 lb. ft.
As well as electronic fuel injection, the new engine has Ducellier electronic ignition; there are no mechanical contact points, and the spark is triggered magnetically.
The new model is available only in manual transmission form, and has a five-speed gearbox as standard. There are no plans to make the GT available in the future with C-Matic transmission.
All five gears are indirect, both fourth and fifth effectively increasing the gearing. In fifth gear, car speed at 1,000 rpm is 21.1 mph, compared with 19.2 mph for fourth gear of the ordinary 2400. One would have felt that an appreciably higher ratio could have been used for fifth to justify the extra cost of a five-speed gearbox, but CitroŽn have evidently been anxious to retain this as a performance gear rather than just a cruising ratio. The final drive unit is the same (4.77-to-1) as in the ordinary CX2400, but it should be pointed out that the former CX2200 used to have a 4.58-to-1 final drive.
Direct comparison of the overall gearing is provided in the following table:


Existing CX2400 New CX2400 GT (sic)
Gear
Overall ratio
Mph/1000 rpm
Overall ratio
Mph/1000 rpm
1st
15.11
4.89
15.11
4.89
2nd
8.72
8.45
8.72
8.45
3rd
5.39
13.50
5.96
12.40
4th
3.81
19.20
4.48
16.50
5th
-
-
3.5
21.10
Above left: Special wheels identify the CX GT (sic): they were not fitted on cars made available for road impressions in France
Above right: A badge showing stylised GTi letters appears on the C-post on each side
Above: As installed, the injection pipes and trunking are adapted neatly to the available shape. The gearbox is in line with the engine, and in front of it is the pump for the hydraulic system

Other mechanical details of the new GTi are the same as for the 2400. The engine has bore of 93.5 mm and stroke of 85.5 mm, to give 2,347 c.c. capacity. The engine is mounted transversely at the front, inclined forwards at an angle of 30 deg. It drives the front wheels, the gearbox being in line with the engine, on the left-hand side of the car as seen from above.
Suspension is hydropneumatic, all-independent, with self-levelling provision, and the steering is CitroŽn Varipower, with powered return to the central position even after stopping the engine. Disc brakes are used front and rear, ventilated at the front.
As well as the more powerful engine and five-speed gearbox, the CX GT has special wheels with centre pressings in the form of a large five-pointed star. Michelin XVS 185 HR 14 tyres are standard.
The surrounds of the side and rear windows are finished in matt black, and there are black side stripes. Embellishing panels along the door sills and a GTi badge on the C-post finisher strip help to identify this top performer in the CX range.
There is also an outside mirror on the driver’s door, electrically adjustable from inside.
Chief interior change is the surprising use of leather for the seat upholstery and map pockets front and rear. The seats are in black or linen coloured. Interior roof trim is in Taragon, and there is a special loop-pile carpet claimed to give added sound-deadening.
Other features special to the GTi are a leather gaiter for the gear lever, illumination for the front ashtray and the ignition lock, carpet in the glove compartment (!) and black trim for the facia, steering wheel, and centre console. A water temperature gauge - omitted from the standard CX instrumentation - is added below the main instrument cluster, and the two-speed wiper has intermittent action as well as continuous wiping. A roof aerial and door-mounted loudspeakers with trim covers as for the Prestige are fitted as Standard.

On the road

Opportunity for driving impressions was provided by CitroŽn on an interestingly varied route in southern France, with GTs (sic) devoid of all badges and without the special wheels, so that other French motorists would not notice the then-unannounced car.
As well as the over-riding impression of a far more eager engine, devoid of that slight trace of hesitance which tends to be noticed with the carburettor versions, the new unit impressed with its much greater refinement. It is appreciably smoother, and has no noticeable rough periods.
Fifth gear is not high, of course and the lazier kind of driver will appreciate the way in which the car accelerates strongly in this ratio. Yet it also provides a very low level of noise at 100 mph cruising. The car tried tended to have an unusually high wind noise level especially on the driver’s side, suggesting a faulty seal, and this was the more dominant feature when driving fast.

Above: The additional air trunking and fuel injection is neatly installed, making good use of available space. The sensor unit is hidden away at the front, on the right side of the car (left of picture here)

CitroŽn claim a top speed of 118 mph for the GT (sic) (against 113 mph for the standard 2400). There was no opportunity to make timed test runs, but 193 kph indicated on what seemed an unusually accurate speedometer (still the strange CitroŽn digital type) certainly supports the claim.
As seen from our table of gear speeds, fourth falls about midway between third and top of the standard car, and proves a really good performance gear giving the CX GT (sic) the sort of mid-range acceleration for fast overtaking which it has always lacked. The gearchange is strongly spring-loaded towards the third-fourth plane of movement and if one forgets to move the lever firmly to fifth, it is likely to finish up back in third. When this happens, the driver is well aware that the wrong gear slot has been taken before releasing the clutch, so the only problem is the need to try again.
Reverse (gear is found by pushing the lever down against the safety spring, and bringing it back, parallel with fourth gear. Fifth gear is offset, in the position taken by reverse on the four-speed car.
Any driver finds the handling of the CX, and particularly the ultra-sensitive and varying-assisted steering, a little unsettling at first acquaintance. It is a unique conception of car steering which takes some getting used to, but with familiarity it gives precision and ease of control with low effort. This aspect of the car, though, is the same as on all the CX range.
The only disappointing aspect on this preliminary assessment of the car was the lack of support provided by the new leather seats. They have inadequate rounding of the sides of the squabs, so the driver ends himself using the steering wheel for lateral location and the passenger tends to slide from side to side on the seat. The appearance of the seats is impressive, but in other respects the standard nylon-cloth-upholstered ones are both more comfortable and give better support. Perhaps CitroŽn will be persuaded to offer these as an alternative to the new leather ones.
In other respects the GT brings new appeal to the CX by adding the performance element and taking away the former impression of a car that is desperately under-powered. The GT gives such better response that the driver no longer feels he is having to row the car along. It should also prove more economical since the engine is more efficient and the gearing a little higher. Unfortunately, although now on the market in France, the GT (sic) will not become available in this country until September. Potential buyers of a CX2400 will find it difficult to decide whether the extra refinements of the GT are worth the added wait.

Autocar couldn't seem to make up their mind whether the car was a GT or GTi and their use of the dierisis is not consistent either.

I emailed Autocar and asked their permission to publish this article but they did not respond.
I assume therefore that they don't care.
© 1977 Autocar/2011 CitroŽnŽt