Making 750 Horsepower
At this horsepower level, the 6.0's start running into some major road blocks. The intercooler starts giving owners problems with the increased air pressure of aftermarket turbochargers and a good aftermarket intercooler is a must. In addition to changing intercoolers, the EGR system needs to be removed or deleted. The EGR system flash boils the coolant which is one of the reasons the engines blow head gaskets. Head studs are a must at this power level. What size injectors the owner decides to use, depends on whether the high pressure oil pump (HPOP) needs to be upgraded. As I write this today, there are multiple companies working on modified HPOP's, but there is not one on the market yet to purchase.
Layton continues, "If the owner wants to use nitrous, they can make 750 horsepower with 255 cc injectors and probably a 65 mm turbo."_
"Injectors that are over 190 cc's need to have an aftermarket fuel system. With injectors that flow 255cc's a large aftermarket fuel system is necessary,"_ says Bennett.
If you don't want to use nitrous, then larger injectors like 295 cc's and a compound turbo setup is the best option. Nitrous really helps burn all of the fuel and you can get higher horsepower numbers with smaller injectors. With only relying on a turbocharger(s) you need larger injectors because you have to light off the turbo.
In addition to this, the transmission needs to be fully built and a billet input shaft is required as well as a custom torque converter.
"People don't necessarily understand that with more horsepower, they need a different torque converter,"_ says Ron Wolverton from Sun Coast Transmissions. "The torque converter is really the only thing that connects the transmission and engine together. So getting one that is tuned to the horsepower of the engine is really important."_
At this horsepower level the rods are uncertain. Some trucks are able to make 750 horsepower and nothing breaks, others "kick a rod"_ out the side of the block and trash the entire motor. So, aftermarket rods are something to consider. In addition, when adding head studs, fire ringing is, also, something to consider as well as porting the cylinder heads.