So I currently have a BD Cobra S361/S476 compound turbo set up on my 2006 5.9 Cummins. The goal for the truck was to make a quick daily driver that was a very competent tow rig. I wanted to keep the RPM operating range the same as stock to keep drivability without the need for manual shifting or messing with shift points. Basically I wanted the truck to drive the same as as it did stock just with more power.

The compound kit in its original form was terrible for that as the exhaust housings were so large that it did not build boost until about 2200 rpm and although it did great on the dyno (650hp 1100ftlb) and in a drag race it was not enjoyable for daily driving or towing. To fix this I swapped for tighter exhaust housings putting a .83ar ungated on the s361 and a 1.15ar ungated on the s476. The end result was exactly what I originally wanted. Truck builds boost at 1500 rpm and carries all the way up to redline (3250rpm) with egts staying sub 1150 at W.O.T. with 57psi boost.

This leads me to my question. I tried to find an answer in the search bar and could not find an answer. If my EGT's are in check do I need to worry about drive pressures? Both turbos are ungated, the manifold has a port for a wastegate but it is not being used currently and BD is telling me if my EGTs are good I don't need to worry about drive pressure and my tuner controls turbo speed through fueling. Is this correct or do I need to get an externa gate on that manifold?

 

What is your drive pressure? Do you also measure between the turbos?

 

Not currently monitoring either, that was the point of the post. If my EGT's are in check do I need to worry about drive pressure. Does drive pressure and EGT's move hand in hand or could i have excessive drive pressure and low EGT's at the same time?

 

Drive pressure can be high and still have cool egts. If everything stays in check then you don't need to worry about it.
Personally I like to have a drive pressure gauge. Over time you learn where the gauges should be at, if something is off, you'll know. But that's just personal opinion.