Key modifications can create a genuine wolf in sheep’s clothing out of the humble Chevette
Unusually for a mainstream family car, the Chevette line-up was always very simple. Initially there was just a three-door hatchback with a 1256cc four-pot engine; later there were two- and four-door saloons as well as a three-door estate and a van – the Chevanne. The big news came in 1978, with the arrival of the 2.3-litre HS. Vauxhall was keen to promote the Chevette as a young person’s car, and its strategy was to take on the might of Ford by getting involved in motorsport; it boosted the baby Vauxhall’s credibility, but with just 400 cars built was only ever a halo-effect derivative. Things got even fruitier in 1979 when 32 HSs were developed further to create the HSR, complete with four-link rear suspension and up to 200bhp.
Nowadays, most Chevettes have been modified in some way. In terms of making the standard car more reliable, a Talbot Lotus Sunbeam alternator copes better with engine bay heat; the high temperatures also take their toll on the starter motor, so fitting a high-torque unit is a good move; a Bedford CF ambulance starter motor was the done thing in period, but you’ll struggle to find one now. Malcolm Davis, chairman of the Chevette Owners’ Group, says: ‘The most common power upgrade is to fit the 2.0XE engine as used in various Astras, Calibras and Cavaliers. This provides a reliable 150bhp and is a straightforward swap using either a Manta five-speed gearbox or an adapter plate and Ford Type 9 gearbox. With the Manta gearbox, a modified Manta propshaft and rear axle can be used. The Manta A axle is rare but ideal because it’s the same width as the Chevette’s. The Manta B axle is 30mm wider and may require wider rear ‘arches.
The 115bhp/130bhpVauxhall 2.0-litre eight-valve is also a common swap. The Ford 1600 used to be a really easy power upgrade but now the parts are harder to find.’
EXHAUsT £400+ The original cast-iron manifold is efficient, but the sealing rings came from a Bedford TK truck and fail quickly. Get a stainless steel tubular manifold made – PD Gough produces one that’s a straight swap for the original. PrOPsHAFT £60 The propshaft is unusual in that the front section incorporates a torque tube mounted to the floorpan. If the bolts snap, the floorpan can be ripped out. The answer is to fit bolts with a much higher tensile strength. ELECTriCs £25+ The Chevette’s electrical system incorporates just four fuses and no relays. As a result the wiring and light switch burn out. Fitting some extra fuses (either in-line or in an extra fusebox) and relays is cheap and easy. iGniTiOn £150 The Delco distributor is poorly made; shaft wear leads to an inconsistent dwell angle. Fit a Bosch distributor if you can find one, otherwise converting to a Lumenition electronic ignition system is the next best bet. BrAKEs £400 The Chevette HS’s brakes – front discs and rear drums – work OK but lack feel. Wilwood calipers with Carlton discs is a popular conversion. A VW/Peugeot rear disc conversion is possible but isn’t a straightforward swap. CLUTCH £250 The right manifold and carbs produce an extra 60bhp, which gives the clutch a hard time. Fit an uprated clutch kit with a Firenza 2.3 cover and special centre plate; the key is to use something with stronger springs. The standard twin Stromberg 175 carburettors strangle the engine so you’re better off with a pair of Dell’Orto 48s. They make a massive difference but you need the correct manifold to make it all work properly. CArBs £600+