Common sense says more air requires more fuel. Adding boost will effectively provide more air to the engine and without an increase in fuel, the Fuel/Air ratio will be too lean. If it was as easy as turning an adjustment screw, everyone would be driving 600hp monsters..
Need help settling a debate on another group. Guy says a simple waste gate adjustment will give massive power improvements, as much as 40 HP on a turbocharged engine. I say he is full of it and will gain nothing unless he also adjusts the fuel delivery and timing.
Jerry
Those Cummins guys are shimming their wastegates and getting very noticeable gains. I have seen that first hand.
Not enough to make me give up my SuperDuty, though.
Spdloader
Shimming the waste gate???
Jerry
Yep, I don't know if it was shimmed shut, or shimmed open. Your question prompted me to ask him today what exactly he did. I'll get back on it when I talk to him.
Spdloader
You don't specify gas or Diesel. If it is gas, don't screw with the waste gate. If it is a Diesel, the max turbo pressure can be changed by manipulating the waste gate. The waste gate is used to limit boost pressure for various reasons including emissions. Another reason for the waste gate is to use a large enough turbo to get strong boos off the bottom end while limiting the boost as the engine speed increases. Without a waste gate, the turbo is configured to match the intended peak engine output and load. The more induction pressure, the greater the power output. You cannot have a lean condition in a Diesel if it is running since the intake is not throttled anyway. Engine output and speed are controlled by the fuel system. That does not mean the engine cannot be overstressed or overheated with too much boost. There is a limit to what it can handle.
The engine in question is a gas engine. I have a diesel myself and I know on that if the waste gate is changed by installing a boost elbow (fooler) of some type that fools the ECM into thinking the waste gate signal is still below max then the boost can be increased but still the fueling and timing must be changed to match the boost or all you are going to do is produce more smoke and higher egt's. On a gas engine I would suspect the same applies in some form but I don't know this for sure. Now the person is claiming that on the Lightning a simple pulley change can produce another 130 HP with no other changes needed. This just doesn't seem right to me but as I said I'm not familiar with these. Seems to me the manufacture of the Lightening would have set the ECM to throw a code if boost over design were reached just as Dodge has set the ECM to set a code and start defueling for the Cummins in addition to set a code the service people will see if you break it. Makes sense to me Ford would have something to protect their warranty limitations.
Jerry
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