Ok so for years i've been wondering why tractor pullers take so long to build rpm and boost, and only just thought to google it.
Sorry if this is really obvious to you guys, but this blew my mind.
The diesel pullers run a low compression engine.. Engine compression heats the air hot enough to ignite the injected diesel fuel. With the lower compression, diesel fuel has trouble igniting in the cylinder. This is why you see many of the diesel puller engine start with LOTS of ether assist. To build heat in the cylinder the puller will very slowly advance the throttle to speed the engine. If he pushes the throttle too quickly the additional fuel will cool the cylinder enough that the engine will die. As he advances the throttle he will load the engine by slipping the clutch. As the engine takes more load, the turbo, or turbos will start to build manifold pressure. As the manifold pressure increases the cylinder pressure rises allowing more fuel to burn. The more fuel that burns, the faster the turbo spins, the faster the turbo spins the more fuel. (you get the picture) As HP and RPM build the engine will finally be making maximum horsepower and the clutch can be released. And the pull is ON..
P.S. The low compression is so the turbo can pack more air into the cylinder without blowing a head gasket or worse.
How amazing is that, it's squirting in so much fuel that it can put out the fire.