F1 1970s: part 1- The Car

Special thanks to www.Formula1.com, Google  and wikipedia for all helpful information.

This decade didn’t have numerous developments in the car, but the most significant and far- reaching change was in downforce which brought in drastic reduction in lap times by the end of season. The engine specs were mandated with 1500 cc compressed engines and 3000cc non-compressed engines being the maximum allowed. The minimum car weight limits increased from 530 kg to about 575 kg by the middle of the decade.

The limitation on wing and other down force elements size was introduced at the start of the decade.  

Ground Effect

Though wings were introduced in the earlier decade after success by the Chaparral team in the Can- Am series, the concept of ground effect hadn’t been understood. Ground effect not only increased the straight line speeds but increased the cornering speeds too. It has also increased the emphasis on setup as small changes create a larger effect on the balance and hence handling of the car.

By the late- 1970's, Colin Chapman from Lotus introduced concept of ground effect in F1 with the inverted aerofoil in their cars which lead to large increase in speed (though arguably pioneered in Chaparral 2J as early as 1970 for racing).

Note: Ground Effect is similar to the principle (Bernoullis principle) used by planes to rise up in the air, except that in this case the car sticks to the ground due to a suction force that is developed between the car and ground (due to increased air acceleration as the ground moves backwards metaphorically, and lowered air pressure). This leads to the ability of the car to drive upside down at high speeds theoretically.

Brabham bt46b (© http://cache.gawkerassets.com/assets/images/12/2011/11/bt46b_1.jpg)

Brabham went a step ahead by introducing a fan to increase the down force but this race winning element was banned by the end of the race as it was considered a movable element (akin to the banned movable wings).

The airbox (As seen in below picture) on top was banned.

The Turbo Era
While Supercharged engines were introduced in the 1970s, it didnt really pick off until Renault joined F1 as an engine supplier in the 1977 season and came in with the Gordini V6 Turbo. It was not all a smooth transition due to the resultant Turbo Lag. It was not until the end of the 1979 season, that the full impact of turbo engines were realised with the Williams winning some races towards latter half of season.

© http://members.fortunecity.com/alicat1/095tf1f.jpg

Note: Turbo Lag is the time taken to change speed efficiently in response to a throttle change.

Fuel Tanks

The now predominant saftey fuel cells were introduced in 1970 followed by safety foam presence in fuel tanks with minimum thickness of magnesium increasing to 3mm.

Slick Tyres
Slick tyres were introduced this decade, taking over the road grooved tyres that were being used earlier. The advantage being that traction increases a lot with the increased contact with road. The disadvantage being it becomes very difficult tyre to drive with in damper conditions.

© http://www.grandprix.com/jpeg/bc/Hill-G_68_monaco_01_bc.jpg / http://userdisk.webry.biglobe.ne.jp/006/305/30/1/1978_jps_mkiv_lotus_79.jpg

The image on the left depicts Graham Hill's Lotus in 1968 with grooved tyres (shown in red) and the right image depicts a 1978 Lotus with slick tyres (shown in blue).