Summary of Specification for Brisca F1 Stockcar
General: The specification for a Brisca F1 Stockcar controls many areas of car construction and equipment that can be used but still leaves some potential for individual creativeness. As contact with other cars and the fence during racing is inevitable and the whole basis of the sport, mistakes in chassis design can soon result in a very damaged car! However, as the specification requirements for safety aspects such as roll cages is well controlled, the driver is well protected.
Minimum: 1350 kg
Maximum Inside Wheels Weight: 52.9%
Minimum Rear Axle Weight: 55%
Engine: No limit on engine capacity but aluminium blocks not allowed and superchargers/ turbo chargers not allowed - must be naturally aspirated (carburetor). Aluminium heads allowed. Due to the weight of the engine and the contact nature of the sport, one of main concerns is keeping the engine in place! The engines have front and rear steel plate engine mountings that are bolted to the engine and chassis - on occasions these can still be damaged and bolts sheared, mountings bent due to the high forces involved. The useable torque/power of the engine is restricted by the size/configuration of the track and the tyres we are allowed to use. The most common engine in use is Chevrolete V8 but many engines are now built using after market parts with not a GM part used! Standard blocks used to limit the size of engines but these limits have stretched with the development of of non GM blocks. There are no restrictions on the parts used but as there is an effective maximum useable torque/power output from the engines, it is not necessary to go light weight or use exotic materials as a basic forged construction engine can handle the output. Drivers can use whatever parts and build their engines for whatever output they require but there are limited advantages in throwing excessive money into the build but some still seem to! What is important is to have a torque curve matched to our racing requirements and as straights are short and we don't change gear whilst racing, a flat torque curve is the way to go.
Engines for 2010 season, on the left 496 BBC on the right 434 SBC. See details below
#92 Tar Car Specification:
Chassis: Built by Alan Brooke, can be classed as a "space frame" design with 80mm x 40mm main rails structurally braced to a full length 40m x 40mm sump guard and top bar from roll cage to front of car also structually braced to the main rails. Roll cage designed to suit a Kirkey series 53 full containment seat.
Engine: Peter Knight 434 cu inch (7.1 litre) Small Block "Chevrolet". Dart block with Dart aluminium race heads, Dart inlet manifold, forged race pistons, rods and crank, MSD distributor and ignition and full modifications for left turn oval racing. Dyno tested : ????? bhp. Max 6800 rpm.
Carburetor: 825cfm Oval Race Demon
Clutch: Quartermaster 7 1/4 inch dia triple plate racing clutch using hydraulic slave cylinder.
Gearbox: Doug Nash 2 speed and reverse alloy racing gearbox. One "fixed" forward gear for use in pits and for rolling lap, second gear ratio can be changed to suit track.
Overall Gear Ratios available in the range 5.47 to 6.51 and we also have a few gear sets we probably will not be using but we will have to see how it goes.
Initially we will use an overall gear ratio of 6.3 which has been suggested for NIR so we can try out and work out other ratios required from there.
6.3 overall ratio 26/29 gears with a high ratio of 1.115 and our 5.7:1 ratio LD rear differential
top speed =
[6800 (rpm) x 24 (nominal rear wheel dia)] divided by [6.3 (overall gear ratio) x 336 (conv fact) = 77.1mph
We base the above on a maxium of 6800 rpm at the end of straight but in general the rear tyre diameter varies and may be more like 24.5inch plus there is the possibility of some wheel spin and of course different tyre diameters across the axle!
I will update this section when we work out all track required gear ratios
Axles: Unshortened Bedford LD rear axle (5.7:1 locked differential ), modified Ford Transit front axle.
Suspension:Spax coil over shock absorbers all round. 3 link rear suspension with radius bars to "bird cages" on axle and central top adjustable link to rear and panhard bar for lateral axle location. Front suspension with single radius bars each side and panhard bar.
Steering: LDV power steering box with KRC power steering pump
Brakes:Twin master cylinders, one for front brakes, one for rear brakes with bias adjustment between back & front brakes from inside car. Proportioning valve to adjust pressure between front inside and outside calipers, adjustable in car. Transit calipers with larger caliper on front outside. EPC brake pads
Weight: to be confirmed
#92 Shale Car Specification:
Chassis: Built by Andy Smith (1997?)and bought as a rolling chassis from Neil Smith in 2003. Fair few modifications by Neil and by ourselves! 70mm X 70mm "well rippled" main rails.
Engine: Based on standard 4 bolt main 454 cu inch block, bored and stroked to 496 cu inch, aluminium race heads, forged crank rods and pistons. Compression ratio 10.7:1. Dyno tested 607 bhp@ 5900 rpm, 602 ft lbs torque @ 4400rpm.
Carburetor: 1000cfm Oval Race Demon
Clutch: Quartermaster 7 1/4 inch dia tripple plate racing clutch using hydraulic slave cylinder.
Gearbox: Doug Nash 2 speed and reverse alloy racing gearbox. One "fixed" forward gear for use in pits and rolling lap, 2nd forward gear ratio can be changed to suit track
Axles: Shortened Bedford LD rear axle, locked differential ratio 5.7:1. Shortened transit front beam axle
Suspension: Spax coilover shock absorbers all round. 3 link rear suspension with radius bars to "bird cages" on axle and central top adjustable link to rear and panhard bar for lateral location. Front suspension with single radius bars each side and panhard bar.
Steering: LDV power steering box with saxo electric power steering pump
Brakes: Twin master cylinders, one for front brakes, one for rear brakes with bias adjustement between fron and back brakes from inside the car. Proportoning valve to adjust pressure between front inside and outside calipers, adjustable inside car. Transit calipers, EPC brake pads.
Weight: 1390kg (to be confirmed with new engine)
Nickname: RAM (registration is R700RAM)
Base Truck: Renault Premium 18 ton sleeper cab chassis with 28 foot box. 280bhp engine
Workshop / garage: Approximately 18 feet long with full height rear door / hydraulic tail lift platform. Additional extension to tail lift to take car. Winch installed and area for tool storage, welding set, etc. Side access door
Outside Lockers : Four external lockers housing generator, wheels, engine driven pressure washer, hose reels for water and air, batteries for living accommodation, battery charger , spare parts area, barbie, etc.
Living Accommodation: 3 fixed beds + seating to convert into further beds, shower, toilet, TV, microwave oven, fridge/freezer, access to cab. Side access door and pull out steps. Water storage tank built in truck chassis, 12v and 240v power by 12v batteries, 12v to 240v inverter, or generator, charging from secondary alternator and battery charger.
Painting: Steve Reedman