Opel Manta A
Reviewed by Unique Cars and Parts
Our Rating: 3
Released in September 1970
, the Manta A may have beaten the Opel Ascona to the showrooms by 2 months, but it was always a rearguard action by GM to try and break the dominance of the Ford Capri
. And in the Capri mould, the Manta was a two-door "three-box" coupe. In the UK market the first Manta was sold only as an Opel: there was no Vauxhall-branded Manta (or Ascona) until after the launch, in 1975
, of the Manta B1
and Ascona B.
The Manta was normally equipped with either a 1.6 or 1.9-litre CIH engine, although in Europe the small 1.2-litre engine was offered. All Mantas sold in the USA. had the 1.9 litre and larger heavy duty radiator (an option on European models). It came with either a 4-speed manual or an optional 3-speed TH-180 automatic. The Manta quickly established a reputation for being one of the best handling cars in its class and went on to win a large number of rallies in Europe and the United States.
The Manta Rallye
Such was the cars success in rallies around the world that Opel created a special sport model, and appropriately called it the “Rallye”. Available from 1971
, the sports model was equipped with extra gauges inside, and had some cosmetic changes made to the exterior, the most noticeable being the addition of a black bonnet and, on 1970
models, the addition of fog lamps. Mechanically the only difference was the gear ratio in the models with manual transmissions, and the Rallye model came with standard stiffer suspension, tighter turning radius, and very aggressive front caster adjustments. Both had dual rear sway bars, providing the best in class handling.
The Manta Luxus and Blue Max
Opel also released the "Luxus", and as the name implied this model was tilted toward the prestige end. Refinements included corduroy seats, colour-coded interiors (blue or burgundy), and faux wood panelling. The only special edition Manta produced for the U.S. market was the "Blue Max" in 1973
– Opel took a blue Luxus model, added a unique dark blue vinyl roof, mechanical sunroof, and automatic transmission.
Electronic Fuel Injection
fitted the Manta with the Bosch L-Jetronic fuel injection in the United States due to emission regulations. Yet in Europe this feature was only available on the high end GT/E Models, which also sported fog lamps and a lower front spoiler. Pollution was not the only consideration, as stringent safety legislation also had to be complied with. US Mantas from 1974
were fitted with large aluminium 5 mph (8 km/h) bumpers - ugly but they worked. At the time the Deutsche Mark was becoming stronger, and with other costs also rising, US imports of Opels ended in 1975. GM instead turned to the Isuzu Gemini version of the T-car, which was imported from Japan and sold by Buick dealers as the "Opel by Isuzu", later "Buick Opel".
The Manta Berlinetta
The European market had a number of different versions of their own. Most were basic trim packages, the most popular being the "Berlinetta", which was similar to the "Luxus" but included rubber trim on the bumpers (standard on all 1973
U.S. Opel Mantas), vinyl roof, and other misc. features. The one major exception being in 1975
Opel offered the GT/E and a number of special editions based on the GT/E. The GT/E was a fuel-injected version of the European 1.9 litre and the performance figures were very impressive for the time. Most notable special editions models based on the GT/E were the "Black Magic" (with black and plaid interior), and the "Swinger" edition in white with an equally odd interior choice.
Given the obsession with power, particularly in the US market, it was only a matter of time until Opel decided to increase the capacity of the Manta. Two projects were initiated in 1972
, a 6 cylinder version and a turbo 4. The latter was dubbed the Turbomanta, and this version is the rarer of the two, as production only totalled around 5 prototypes. British company "Broadspeed" were given the task of adding a turbo unit to the 1.9-litre "S" spec engine - originally developing 90 bhp (67 kW) . Broadspeed came up with a somewhat special solution, and used a combination of a Holset 3LDG turbocharger, and a carburettor mounted inside a big plenum chamber.
The engine itself was fitted with a thicker copper head gasket, and as such the compression ratio was lowered to 7.6:1. The outcome was a 1.9-litre engine which put out a staggering 156 bhp (116 kW), and more impressive was the acceleration. 0–60 took a mere 7.6 seconds, faster than most "supercars" at the time, and even faster than the Porsche 911. All 5 prototypes were in GM "signalgelb" sunflower yellow, and had a large black stripe on the side, where a sign said "TURBOMANTA". But the Turbomanta was not without fault, although this was mainly felt at the petrol station (or in the number of times you would need to re-fuel) - the turbocharger managing to halve the fuel consumption of the naturally aspirated 1.9 litre unit.
At a time when fuel consumption had become the mantra in the media, Opel
decided the Turbomantra would be a hard sell, and given the extra costs associated with the cars development realised it would not be economically viable. The turbo project was closed, leaving the 5 cars as the total production number. However a British engineer at the D.O.T (Dealer Opel Team, which was the British importer and builder of Opel cars in Britain) was so enthusiastic about the cars that he had D.O.T. build an additional 28 cars. The cars were all based on the 1974
Berlinetta model, which was the luxury model, with a full gauge pack, automatic transmission, and alloy wheels
. All 28 cars were black, with vinyl roofing. The only thing identifying that the car was indeed a Turbomanta was a small emblem at the rear quarter of the rear wings saying "turbo". Very few of these cars remain today.
The Belgian company Transeurop Engineering also wanted to up the engine power of the Manta A. Opel had previously tried a 6-cylinder engine layout in 1971
, but with little success, they being considered too expensive to build. Transeurop Engineering did not agree with Opel, so they took a 2.8-litre CIH type engine from the Opel Commodore 2.8GS model and fitted it into the engine bay of the Manta 1.9SR. But the transplant was not an easy one. The radiator, bonnet, the entire front end of the car, the rear axle, the transmission all needed to be changed. Heavily committed to the project, Transeurop suddenly realised why Opel had deemed the 6 cylinder idea as being too expensive.
Transeurop initially tried to get Opel to join the project, but their requests for help fell on deaf ears. Even worse, Opel
didn't want the Opel brand on the cars, if the project ever became a success. Transeurop Engineering turned to Opel's number one tuner of the time, Steinmetz, who agreed to help and supplied a new fibreglass bonnet to make room for the two front cylinders, a set of widened arches, and a special front bumper integrated with the lower front spoiler, to make room for the dramatic changes that needed to be made to the cars front end construction. A closed radiator system was installed so that the radiator had a water tank in the engine. This fibreglass bonnet was much lighter than the standard pressed-steel version and it formed part of the program to preserve the weight distribution of the original Manta in spite of the bigger engine. This plus a spoiler-shaped lower front panel into which the bumper was integrated and moving the battery
to the boot did maintain the original 55/45 weight distribution.
Shoehorning the 6-cylinder engine into the Manta's engine bay involved cutting out the front transverse structure holding the radiator. To restore adequate stiffness a U-shaped tubular cross-member was bolted between the body side rails, together with new front engine supports. At the rear of the engine compartment it was necessary to hammer out a slight recess to accommodate the larger gearbox that went with the 6-cyl engine. With the additional power the running gear also got its share of changes. Ventilated discs replaced the solid disc brakes
at the front, although the rear drums were left standard. Stiffer front springs were fitted, and shock absorbers with slightly harder settings were used all around.
with 7-inch. rims replaced the originals, and the guards were flared to accommodate large 195/70HR-13 Kleber V10 GTS tires. The Manta's optional limited-slip differential was mandatory and the gearing was 3.18:1. although the usual Manta final drive ratios of 3.44 and 3.67:1 could also be obtained. Recaro reclining seats were used and a beautiful leather-covered Nardi steering wheel replaced the Opel wheel. A different speedometer and tachometer matching the car's performance were from the Commodore GS. Overall workmanship was so good that there was nothing to disclose that the TE 2800 did not come straight from the Riisselsheim assembly lines.
After putting the car through its paces, the Opel factory and General Motors Continental in Antwerp finally agreed to back Transeurop chief Vic Heylen. Opel would provide Heylen with engine-less Mantas and 6-cylinder engines, thus enabling Transeurop to put the car into small-scale production. Changes in the management of both Opel and GM Continental delayed the agreement and when the first production cars left Transeurop's premises it was the end of 1973
- just in time for the fuel crisis. Nevertheless, all parties concerned agreed to go ahead with the project, there being no doubt that the world was large enough to absorb the planned production of five per day whatever the restrictions may be.
The production version of the TE 2800 used the 2800 HC engine, which with twin 2-barrel carburettors was used in the Opel Admiral and Commodore GS/28 and produced 142 bhp DIN. It was preferred to the 160-bhp version with electronic fuel injection not only because it was cheaper but also because it could more readily be tuned to suit various emission requirements. Transeurop used the Commodore four-speed manual gearbox and a 3.18:1 rear axle, enabling the Te2800 to go from 0–60 mph in just 7.5 seconds. A total of 79 cars were made and sold through Steinmetz in Germany - branded not as an Opel but as a TE2800. All Opel brands was removed from the cars and replaced by the logo "TE".
Steinmets offered a tune-up for rally and motorsport use. The tune-up consisted of porting and flowing the head, higher compression ratio, a race spec camshaft, and triple carburettors, giving the car a total of up to 230 bhp (172 kW). No doubt that the TE2800 was the fastest Manta A ever made, even though officially it wasn’t an Opel. At the time prototypes were still eligible for motorsport, so the TE2800 was then entered in the 1971
Tour of Belgium, a rally counting toward the European Rally Championship. Driven by the late Chris Tuerlinx, it won several special stages and finally finished 7th after losing two cylinders. The official rally version of the TE 2800 featured stiffened-up suspension
, 8-in. rims and an engine tuned to produce 230 bhp DIN with three Weber carburetors. A special camshaft and a modified head could also be had, but the standard version was intended as the fast road car.
Behind the Wheel
Though the standard engine made the Manta as docile as any Opel in traffic, the performance was what you would expect from 142 bhp DIN (about 135 SAE net) weighing under 2500 lb and benefiting from both small frontal area and reasonably wind-cheating lines. But few road testers were able to obtain the maker's performance figures, which were - 0-60 mph in 7.6 sec, 0-100 in 22.2 and the standing-start kilometre in 29.2, and a top speed of 128.5 mph. 2nd gear could pull up to 63 mph and 3rd to 100, both these speeds corresponding to the 6200-rpm red line. These were all very creditable figures for a perfectly civilized, silent road car costing about half as much as a basic Porsche 911 of approximately equal performance.
The most surprising aspect of the car was its handling. Easing the throttle at a high cornering speed reduced the slight understeer to a near-neutral behaviour. Even right at the limit there was never any need for drastic steering corrections. The TE2800 could be driven easily at any speed. The Manta/Ascona rack-and-pinion steering was well known for its lightness and even the combination of a heavier engine and the wide Kleber radials did not make it heavy. At just under four turns lock-to-lock it was fairly low geared for a fast and sporting car, but with the quick response provided by the wide tyre-and-rim combination and the slight negative front camber this was hardly felt unless a really sharp turn had to be made.
Transeurop Manta TE2800 Quick Specifications:
Transeurop Engineering, SPRL 3540 Bolderberg Zolder, Belgium.
Type - .sohc inline 6; Bore x stroke, mm - 92.0 x 69.8; Equivalent in - 3.62 x 2.75; Displacement, cc/cu in - 2753/168; Compression ratio - 9.5:1; BHP @ rpm, DIN - 142 @ 5200; Equivalent mph - 117; Torque @ rpm, Ib-ft, DIN. 160 @ 3400; Equivalent mph - 76; Carburetion - two 2V Zenith 35/40 INAT; Fuel requirement - premium, 97-98 octane.
Curb weight, lb (mfr) 2200; Weight distribution (with driver) front/rear, % - (mfr) 55/45; Wheelbase, in 96.2; Track, front/rear - 55.0/53.5; Length - 171.0; Width - 67.0; Height - 51.2; Ground clearance - 7.0; Fuel capacity, U.S. gal - 12.8.
4-sp manual; Gear ratios: 4th (1.00) - 3.18:1; 3rd (1.36) - 4.32:1; 2nd (2.15) - 6.83:1; 1st (3.42) - 10.90:1; Final drive ratio - 3.18:1; Optional transmission - 5-sp ZF manual.
Chassis and Body:
Layout - front engine/rear drive; Body/frame - unit steel; Brake systen - vented disc front, drum rear; vacuum assisted; Wheels - cast alloy, 13 x 7J; Tyres - Kleber V10 GTS radial, 195/70HR-13; Steering type - rack & pinion; Turns, lock-to-lock - 3.8; Turning circle, ft - 30.5
Front - unequal-length A-arms, coil springs, tube shocks, anti-roll bar
Rear - live axle with short torque tube, single trailing arms, Panhard rod, coil springs, tube shocks, anti-roll bar
Acceleration (mfr figures): 0-60 mph, sec - 7.6; 0-100 mph - 22.2; Speed in gears, mph: 4th (5900) - (mfr) 128.5; 3rd (6200) - 100; 2nd - 63; 1st - 39.