Once we figure out how to burn 100gpm worth of fuel we'll get those flames up there...
So there's another unique dragbike sound unlike any other, the sound of a Supercharged, Nitro burning Metric Top Fueler. Our Flat-Plane cranks give it a much different sound than that of a Cross-Plane design American automotive 90 degree V-8, same with the V-Twin Fuelers.
Go on Facebook and Listen closely to some of the
CycleDrag videos of Larry McBrides TF runs, there's a lot going on.
Of course they run relatively smooth when we start them on gasoline. The fuel pump is off at the warm up start. Due to using a Screw-type blower the bikes can warm up completely on alcohol; the cars on the other hand go right to running nitro as their roots-type blowers use nylon stripping to seal the rotors, and there is fuel fed above them as a lubricant. The proportionate amount of alcohol would flood the engine.
All of the blown fuelers, both 2 and 4 wheel, idle at over 2000 rpm. There is still manifold vacuum at this point. Even with 300 degrees duration, lumpy cam reversion isn't an issue as low pressure fuel is being injected directly adjacent to the intake valves.
TF Bike motors run about 92 cid vs the NHRA 500 cid, with both burning a proportionate amount of fuel. Generally both roll in to stage at ~2700rpm, with the bike burning 1 gpm vs 5 gpm. Just before launch you can really hear the changes, the car rpms drop slightly as the second fuel pump is turned on, and the bike rpms go noticeably higher to 3500 with the activation of a staging high idle circuit. Motor speed=pump speed=fuel flow. As soon as that additional fuel is present, the pipe (cylinder ) temps drop rapidly in both applications, which could cause dropped (misfiring) holes, so it is a last moment thing. At the hit we see 10gpm vs 60, accounting for the flame height difference.
The thunder of the TF V-Twins now, that's another story. They can run 200cid motors, some with 5 1/4 inch stroke cranks,
They leave at a fast idle and still rev those stroked monsters over 5 grand. Most are normally asperated (injected only) though there are a few blown combinations out there being tried. Many passes are on the wheelie bars past half track over 200mph. Often the front tire smokes once it finally hits the track. These are best experienced live and in person.
