I really don't think so. The
aftermarket BOV seems to cause more tuning problems than what it supposedly solves. From what I can tell, the OEM diverter valves seem to be just fine, that is, they are not limiting the speed of shifts or the power down low; rather, it's how the ECU controls them that makes the real differences. IMO, buying BOV's is a waste of money on our platforms. Save it for your tune!
It's a good question. I would argue that it would be the other way around. I would think that the JB4 is harder on the car/engine because it makes the ECU think that it can advance the timing moreso than it should for a given boost level (ie the ECU thinks it's at 13 psi when it's really at 17 psi, so the timing is more aggressive and thus less safe), so the ECU is left to rely solely on the knock sensors to keep things safe, rather than it being able to be fully aware of all the operating conditions the engine is dealing with. Whereas a flash tune would be able to run more boost without having to only rely on the knock sensors to avoid detonation.
Think about it this way: our engines use the speed density calculation to figure out intake flow. This means that the ECU relies on the IAT sensor and MAP sensor to make calculations as to how much air it thinks the engine is taking in. With a piggyback, like the JB4, at least one of those sensor inputs is skewed (ie MAP, but JB4 can also spoof IAT in certain cases), so the ECU isn't getting accurate info as to how much air is going into the engine. The JB4 can sort of account for this in its own way with its algorithms, but it's not the same (or, arguably, as safe) as how the ECU does it on its own. Remember that we don't know exactly how the ECU factors in intake and
exhaust valve timing adjustments to not only make power, but also to keep things safe. I think it's safe to say that intake flow, temperature & volume play a very big role in said calculations.
That said, the JB4 would probably run less boost for a given HP number vs a similar ECU flash, albeit with much less safety buffers and a more volatile combustion chamber environment. Maybe. But the more I think about it, you might actually be exactly right... Maybe it has to cram more air in because the ECU thinks it doesn't need to adjust the intake/
exhaust valve timing as aggressively to make more power... Hmmm...
Edit: Fixed some grammar and sentence flow, along with clarification of my silly ideas.
