John Napier survived one of the toughest Top Comp fields ever assembled at Perth Motorplex to take home a win on Saturday.

Napier ran a 6.31sec. time to defeat Adam Croker's dragster which had problems on the start line and could not make a pass.

For Napier it was some just reward with the new equipment on board his Funny Car producing a 6.03sec. personal best time during the day, only a fraction off the national record for his class.

Meantime for Croker it was a shattering end to a day that saw him licence his new dragster from the US and run a personal best 5.67sec. time at almost 400kmh, an incredible two tenths of a second under the AA/Dragster national record.

Rob Pilkington made it a Funny Car double for the category by taking out the B Final, defeating Pino Priolo's supercharged Commodore which left the start line too early, producing a foul start.

Pilkington's last pass recorded a 6.00sec. time, just shy of the five second barrier he has been chasing in his imported Monte Carlo AA/Funny Car.

Two more Group One racers were testing ahead of their respective national championship rounds coming up in November.

Mark Sheehan was in the seat of his Top Alcohol Altered but had a hard time putting all of the power down to the track with tyre smoke and wheelstands hampering his times.

John Zappia had his Monaro Top Doorslammer on track with a new clutch set up but a gremlin was causing all the 3500 horsepower to be applied in the first few metres of the track meaning the car just went up in smoke.

Manufacturer battle

The Competition Bike category was dominated by street bikes at the weekend, with a fascinating new battle ensuing between the three manufacturers Kawasaki, Suzuki and Yamaha in the B/Street Bike class.

Neil Anderson paced qualifying with a 9.23sec. pass on his Kawasaki ZX10R, way under the national record for his class. Reg McCallum put in a 9.34sec. for second on his YamahaR1, also under the national record, while Tim McClure's new Suzuki GSXR1000 slotted into third place with a 9.41, just shy of the record.

The final came down to Anderson and McClure with the Kawasaki taking victory in a 9.53sec. to 9.59sec. final.

Meantime Ross Smith stunned onlookers with an 8.99sec. pass on his Suzuki Hayabusa, becoming the first WA street bike rider into the eight second zone. Smith's Hayabusa is naturally aspirated and retains the stock wheelbase, running in the A/Street Bike class.

All girl final

The final of Junior Dragster saw two young ladies battle it out for the honours on track.

Amy Kennedy was up against Nicole Adamos after the pair raced through the 30-strong Junior Dragster field.

Adamos unfortunately red lighted to end her chances of victory, the win going to Kennedy, a second generation racer following on from father Graham Kennedy who races in Super Sedan.

Jamboree re-runs

The 17th Annual Castrol EDGE Jamboree has been run and won in clear weather conditions, with the re-run going off without a hitch at Willowbank Raceway, Queensland on Saturday.

Version two lived up to all of the expectation on the bitumen, with over 200 entrants lining up at the Ipswich track.

As the Grand Final of the 2006-2007 Sport Compact Group Drag Racing Series and with eleven of the classes to be decided on the night tension was high amongst competitors.

The headlining entry of Gary Goodman and Joe Signorelli from Gas Motorsport did not disappoint with their Toyota Celica, powered by a 2JZ Supra engine, taking the Pro Turbo category win on debut with a number of spectacular 6sec. passes.

Coming down to old rivals Signorelli and George Rehayem in the Pac Performance MX6, powered by a turbocharged 20B Mazda rotary, the Pro Turbo final run was a classic piston versus rotary battle, with Signorelli taking the victory with a 6.97sec. pass at 310kmh, subsequently wrapping up the Pro Turbo Championship for the season.

The slated battle between Signorelli and Tony Wedlock in the world's fastest Camry unfortunately did not eventuate, with Wedlock encountering issues including a blown head gasket on his 2JZ engine.

Despite those problems, former ANDRA champion Wedlock was able to put down a few good runs for the fans, with a 7.30 second pass at 314kmh.

What's in a letter?

Many drag racing cars and bikes carry a classification such as AA/Dragster or B/Street Bike.

These letters indicate what class the vehicle runs in, and each class has a national record. For the Group Two categories (Top Comp, Super Comp and Comp Bike) this national record is used for a handicapping system, while for Group Three racers it is purely another achievement to make that does not affect racing.

Typically the earlier the letter in the alphabet, the more engine capacity is allowed. Several other modifications to the chassis and engine may be permitted or excluded between classes.

Several classes now carry letters after the classification including "i" for electronic fuel injection and "a" for automatic transmissions.

It's all very complex, but it means close and exciting racing between lots of different vehicles.