Opel Kadett-E GSi 4x4 - Group B Prototype - Vauxhall Astra 4s 1986

Vauxhall Astra 4s October 1986

[@caprise-music6722]

art of rally

[@scotten34]

The engine was special

[@s3xy1977]

later taken on by john welch in rallycross ( but turbocharged )

[@DarrenH_76]

John used one of the paris-dakar group B kadetts. the group S vehicle in this video still exists today and is in private ownership

[@44ro.n]

saw the car today at the nec classic motor show, looks very nice

[@mantadave]

Manta 400 engine with a supercharger why did they not use the manta instead ?

[@d-d-i]

Because this was 1986, Manta was already outclassed car with its rwd system, heavy old fashioned chassis and N/A engine. This Astra 4S/Kadett 4x4 represented the Opel's rallying future in Group S, that sadly never came. But that Manta engine was a mistake too, Opel wasted time with it, since the CIH type engine isn't suitable for very high performance turbocharged tuning (even thou it was very reliable) and it's too big in terms of weight and dimensions for car like this. Instead, they would have needed 16 valve head for the more modern and compact OHC engine and go with that instead.

[@DarrenH_76]

it had a CIH derived block yes (albeit steel everything inside) but the head was bespoke cosworth twin overhead cam 16 valve pent roof type. the same intrinsic engine was used in john welches 1988 rallycross car with over 500bhp, running only 2.1L, then eventually developed up to 650bhp. admittedly the block was strengthened with ladder frame and integral sump, but still, both were a long chalk from the old "CIH" engines

[@DolleHengst]

@@DarrenH_76 the block they used for the Ascona 400 was the diesel. A big lump of cast iron, but bulletproof. It was bored out to 2.4 litres and fitted with a completely different head and forged internal parts. Pistons, rods etc.

[@Nothing-to-noone]

Yeah, 4S was a modified C20LET essentially different to the Mantas CIH derived 2.4 prototype.

[@mantadave]

It weren t that much of a waste of time as that same engine and chassis won the world rally champship in 1982 in an opel ascona 400 and beat all the 4x4 s on total reliable never saw an astra win fuck all was the worst rally car ever built buy vauxhall opel ?

[@DarrenH_76]

"same engine and chassis" the car in this video has the same basic engine as a manta 400, yes, with a super charger increasing the power from 250bhp to 320bhp. the chassis has absolutely nothing to do with the manta400 what so ever, it was scratch built by gartrac (prototype) and matter motorsport (two paris dakar cars and this 4S). it "never won fuck all" because it only ever entered one race.

[@mantadave]

Same chassis as an ascona 400 not an astra which won the world rally champ in 1982 with that crap engine 5 yrs before the astra was even thought of but it was still running that same engine cos it was ahead of its time and was bullet proof so after all it is a manta and ascona 400 engine in an astra 4s

[@DarrenH_76]

ah ok, just worked out you were replying to "dirty deed indeed" but started a new comment. the reason they developed the manta is purely because the ascona went out of production as a road car. GM did not have a 4x4 road car to be competitive, and wouldn't commit investment to make a homologation special just for WRC, like peugot and ford for example who had to make 200 road going versions of the 205T16 and RS200. Group S (even though it was scrapped) only required 10 cars to be built, GM made 10 (or had parts for 10) and kept them all !