[OldCrow7xx]

So I looked at my logs and it looks like on BM3 stage 2 the car never goes past 80% wastegate duty cycle.

This results in roughly 16-17 pounds of boost actual and targeted. I have ready the stock turbo is healthy at 21 and can theoretically be forced to 24-25 with the right dependent variables.

Based on my readings, the higher the duty cycle percentage the more boost the car is being forced to make beyond the initial spring pressure. This could be wrong but that was my interpretation of notes and articles. 100 percent WGDC would be max boost, and 0% WGDC would be the starting point, or spring pressure commonly 6-7 pounds as a "par" value so to speak. The WGDC modulates additional boost beyond the spring.

So in theory, does this mean I have 20% more boost capacity not being utilized on the stock turbo?

and if so, is that because the stock fuel system can't keep up, or is it just potential waiting to be used?

My car is off warranty and I don't plan on holding it forever, so I would rather take a more "aggressive" or "risky" strategy in running more boost even at the higher long term risk of engine failure. I just want to make more power on this setup.

Thanks for any tips or tricks here.

[AmuroRay]

Yes, no and not really. Yes, a lower duty cycle means you you’re in theory not producing the maximum amount of boost. However, Turbos have efficiency ranges, and regardless of WGDC, you could be outside the range and power limits.

[TYC]

Originally Posted by AmuroRay

Yes, no and not really. Yes, a lower duty cycle means you you’re in theory not producing the maximum amount of boost. However, Turbos have efficiency ranges, and regardless of WGDC, you could be outside the range and power limits.

Your part about the efficiency range is correct.
There is a point of diminishing returns related to how fast you spin the turbo to make more psi.

As i understand it, once you get up past ~85% duty cycle the turbo is working too hard to make the target amount of boost, and just blowing really hot air.
Your also adding un needed wear to the turbo internals.
With BMW logs. the dut cycle is more of a actuator measurement. I.e. how long it has to stay closed to reach the target psi.
If your target is lets say 20psi, and you know you can hit that with 80% duty cycle...then lets say you had a boost leak or actuator failure...you would see 100% duty cycle and be making less boost then your requested target psi. I.e making 17psi, when your target is 20psi, @ 100% duty cycle.

Also, for the OP. Power isnt only from boost.
Timing makes power too (anything from 5 - 10deg of advance is good ).
An engine that can run the same psi boost as you, with more timing adv. then you(safely), will make more power then you.