Endurance Financial RGB Sports 1000: 'Motorsport's Most Affordable Sports-Racing Car Championship'
Front, mid and rear-engined chassis layouts are all permitted.
Four-stroke motorcycle engines from Honda or Kawasaki (pre-2010), Suzuki or Yamaha (pre-2009). Two-stroke designs, multi-engine and forced induction are not permitted. Engines and their ECUs must remain entirely standard and unmodified, but dry sump lubrication and exhaust/induction systems are free.
Suspension design and system is free, although ‘active’ suspension is not permitted.
Braking system is free, with the exception of ABS and carbon-fibre discs.
RGB is predominantly a mechanical grip formula, so wings are not permitted and aerodynamic development is tightly controlled, however there is plenty of scope for the amateur to develop their own car - often from scratch.
The gearbox and its ratios must be standard for the engine with a maximum of six forward speeds; there must also be a system of reverse which will drive the car and driver a distance of three metres and pass one of the wheels over a block 40mm square.
All cars use an Yokohama A048R control tyre, with an Avon wet weather option.
There are typically 14 rounds per season, spread across seven 'double-header' race weekends, of which the best 12 count for the championship.
Club membership is just £25 for 12 months, season registration is £130, and double-header weekend entry fees (qualifying, 1 x sprint and 1 x feature race) are typically between £295 and £395 depending on the circuit. Regulation compliant, proven cars are available secondhand from just £9000.
See links above for full regulations, race calendar, registration, lap records, cars for sale and social media.