Innovation and change is rampant in today's world of professional nitro racing, it is just not apparent to the casual spectater.
The biggest change that led to all the high mph readings was the inside of the injectors and superchargers. The opening size and locations were moved around, front plates were reconfigured, and different stripping materials led to more efficiency at high rpms. The inside shapes of the injectors then needed to be improved. These are two areas that are being worked on constantly.
There are many subtle changes the teams make to their chassis that make a lot of difference in the way the cars perform. Did you know that some funny car teams have different A-arms made up for running in the right or left lanes at specific tracks? That T/F cars are made to 297" wb and have rear end plates made to adjust the car up to 300"? This moves the weight bias of the car which makes it perform differently. They also have different motor plates and mounts to raise or lower the motor. Moving the motor up or down is like moving it forwards or backwards in the chassis.
Clutches and flywheels have changed significantly in the last few years, and are continuing to change today. Clutch fingers, discs and floaters can be a tuner's nightmare at times. And you cannot buy several of the finger styles that are being ran. One significant tuner leases out his style clutch fingers and clutch set ups to several prominent teams.
Fuel systems are always changing and the variations are plentiful. Cams, manifolds, rocker stands, and compression ratios vary widely. Heads change yearly, and I can guarantee the exact heads AJ runs on the Army car are not available for sale to any other team.
And the new chassis tubing size rules are going to make all the data learned obsolete and new innovations are going to be taking place to regain and improve the performances.
Goodyear does have a new tire that was developed and tested with last years rules. They now want to test with the new rules before releasing it for general use. And there is a movement on by some race teams to get a different wheel Okayed to better plant the tires during a run.
Stability in the rules allowed the nitro classes to tighten up as far as performance goes. Money, innovation and hard work is what keeps certain teams ahead of the curve, but others have gotten the resources to fund their team members to put in the time to catch up.
Bottom line, the cars may look the same, but they are really very different from one another.
