The 1970 Trans-American Championship was a motor racing series organised by the Sports Car Club of America for SCCA Sedans. It was the fifth Trans-Am Championship. Ford (Thanks to Parnelli Jones and George Follmer) and still potent Alfa Romeo won the Over 2 Litre and Under 2 Litre titles respectively.
With Porsche's 911 moving to a 2.2L engine, the year marked the resurgence of Alfa Romeo as dominant in the Under 2 Liter class. The year also marked the first win for American Motors, with Mark Donohue driving a Penske Racing-prepared AMC Javelin, winning three races. Also winning for the first time was BMW, in the Under 2 Liter races at Bryar and Bridgehampton.
The championship was contested over eleven rounds with separate races at each round for Under 2 Liter and Over 2 Liter cars.
Points were awarded according to finishing position. Only the highest-placed car scored points for the manufacturer. Only the best 9 finishes counted towards the championship. Drivers' championships were not awarded in Trans-Am until 1972.
1970 was the first and only year that every Detroit "pony car" manufacturer has a factory-backed team in TransAm.
| Pos | Manufacturer | LAG | LRP | BRY | MDO | BRI | DON | ELK | MTB | WGL | SEA | RIV | Pts |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Ford | 1 | 1 | 1 | 1 | 2 | 2 | 5 | 2 | 3 | 1 | 1 | 72 (78) |
| 2 | American Motors | 2 | 13 | 2 | 3 | 1 | 19 | 1 | 1 | 2 | 2 | 3 | 59 |
| 3 | Chevrolet | 5 | 2 | 4 | 4 | 4 | 1 | 4 | 6 | 1 | 5 | 6 | 40 (42) |
| 4 | Dodge | 6 | 3 | 23 | 5 | 20 | 20 | 3 | 4 | 29 | 3 | 24 | 18 |
| 5 | Plymouth | 4 | 10 | 14 | 21 | 21 | 5 | 2 | 28 | 6 | 18 | 4 | 15 |
| Pos | Manufacturer | LAG | LRP | BRY | MDO | BRI | DON | ELK | MTB | WGL | SEA | RIV | Pts |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Alfa Romeo | 1 | 1 | 2 | 1 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 81 (93) |
| 2 | BMW | 2 | 3 | 1 | 6 | 1 | 3 | 2 | 4 | 3 | 2 | 3 | 52 (56) |
| 3= | Fiat Abarth | 6 | 8 | 5 | 14 | 3 | |||||||
| 3= | British Motor Corp. | 5 | 8 | 9 | 6 | 7 | 9 | 14 | 11 | 3 | |||
