Never said Pressure = volume.

 

... with a fueling box added...

maybe maybe not. if the extra fuel produces enough pressure in the exhaust manifold to drive the turbocharger to higher boost pressures, then one of two things are happening: (1) the 'charger is pumping more air molecules into the engine, or (2) between zero and a small number of hotter air molecules are being pumped into the engine. remember that at very high turbocharger speeds, the compressor wheel does not efficiently compress air anymore, it just heats it up. this causes the boost gauge to read higher, and you to think you are getting more air.

remember that the boost gauge can't tell the difference between more molecules or just hotter ones. the goal is not to make your boost guage rise, it is to push more air molecules through the engine.

the objective of additional boost is to push more air through the engine, creating higher combustion pressures and expelling more exhaust heat faster to keep your aluminum pistons from changing shape. if the turbocharger operates efficiently, then the boost elbow would allow the turbocharger to push more air through the engine, causing the needle on boost boost gauge to rise. If the turbocharger does not operate efficiently, then it does not push more air through the engine, but STILL causes the needle on your boost gauge to rise, making you think that good things are happening.
in a word, NO. no no no no no no no no no no!
No. Those who add power responsibly also consider the consequences of the extra heat, what causes it, and what to do about it.
maybe maybe not. efficiency of the turbocharger is not determined by the box or its settings, it is determined by how much heat the turbocharger ALONE adds to the air as it compresses it. The 04.5-05 trucks have a larger turbocharger, adjustable wastegate, and have a much better time accomodating a fueling box. the 03-04 turbocharger poops out at about 50-65 HP.
the use of upgraded intake and exhaust systems and EGT-aware driving can keep maximum allowable exhaust gas temperatures in check. But doing so is putting your head in the sand with regards to consequences you might want to ignore, namely the stresses on the turbocharger. the wastegate is there to prevent over-spinning the compressor, and when you defeat this safety device you may be compromizing turbocharger longevity, even if your EGTs are under 1400.

for the 03-04 trucks, the 'charger wastegate is set to the right point. you don't want the 'charger to spin as fast as it takes to generate 30 lbs of boost with this little charger. poor thing is just churning up the air and heating it up by that point, heating up its own bearings, accelerating wear, and getting ready to distintigrate. and you will be approaching FIFTY POUNDS OF DRIVE PRESSURE in the exhaust manifold just for the fun of watching your boost guage rise in response to hotter, not more, air molecules.

the best way to optimize the health and longevity of your turbocharger is to understand what boost levels it can generate efficiently. maximum EGTs is not a reliable way to to that. For the 03-04 turbocharger, this limit is in the upper 20s, as I have previously described. I haven't tested the newer 'chargers but expect there is significantly more margin.


sorry guys, for the old fueling box page. I'm hoping to do another market scan soon and update the matrix.

 

doug, you hit the nail on the head with this. We have seen this same kind of data with our testing. One way to get more performance from this turbo and make it more efficient is with a Turbo Air Guide (TAG). We have test data that shows with a TAG the volume of air at a given boost pressure increases. One reason for this is the air is cooler entering the intercooler and more dense. If you look down this page you will find the information graph for the Cummins http://www.dieselpowerproducts.com/tag This larger volume of cool dense air is most significant when the engine and turbo are under load such as when towing.