I'll agree and disagree. RPM is A controlling factor. No RPM, no boost. Using your example a little bit closer to earth, large bore engines such as used on tractors, some trucks, crawlers, etc. are turboed in some applications. Sometimes the engines might turn a max of 1000 RPM, so it is all relative. They create the boost because, with the bore size what they are, huge amounts of air is moved through the engine in one stroke. And this is a case where extra load will create extra boost. The engines are running at a constant RPM but put the crawler behind a big pile of dirt and you see the black fumes emanate from the exhaust pipe. You can hear the extra load spinning the turbos more. But that doesn't necessarily apply to trucks or cars.
Load can be achieved by going to WOT and the force needed to move the vehicle is the load. My point has been that with something like the H2, you are at it's threshold by trying to just move the truck and there is not enough engine left to create more boost upon adding additional load from a trailer. It's all about application.
Jonahs, I think I agree with what I think you are saying. I just thought the comment about RPMs wasn't entirely true. A turbo CAN be created that has boost earlier in RPMs thereby increasing torque and with proper control and wastegates handle the top side of RPMs and "overboost".
|