On the "winding it up to 25 Psi" rationale, then that in itself would then demand further the addition of a bov. Think about it for a minute.
What is it that destroys a turbo? (other than outright wear)
High boost on its own wont kill it, altho it might wear the thrust bearing a lot quicker which might lead to an eventual failure.
The higher shaft speeds wont kill it on their own if the turbo was even balanced at all.
What will kill a turbo is driving the compressor/turbine so far out of its efficiency "island" that the stable airflow across the wheels cannot be maintained and the compressor SURGES!
It cavitates. Like an outboard motor propeller "slipping" or cavitating and the forces can be sufficient to destroy the gearbox bearings and actually eat away the prop blade material!
Ever been in a boat with a cavitating prop? Vibration and so-on is pretty major.
This results in extreme fluctuating loadings withing the rotating mass and the thing literally flings itself to peices.
Gee, now, I seem to remember saying exactly the same thing happens with a STALLED conpressor wheel in a previous post!
Given the shaft speeds would be driven well into the extreme ranges over "stock" (whatever that might be on that particular size of engine) and so the fluctuating loads on the rotating components would be multiplied as a SQUARE of the rpm (no, thats right, the loads dont increase proportionately with RPM, they increase as a SQUARE of the rpm) then that would scream out loud and clear the absolute need for some kind of protection in the form of a bov if the shaft speeds are increased (upped boost).
You cannot dispute the facts and figures M8.
"Your humble (or indeed mine) opinion" means jack schitt here. Only technical facts and figures. You cannot dispute them. Opinions are just that, opinions and are disputable until the cows come home.
Saying an e15et driving normally does not need a bov is just bollocks and purely an opinion, NOT based on any technical facts.
It matters not whether you fit a bov loud enough to scare little old ladies
]supersonic mach 16 monster super duper blow off valve
on the other side of the street or a simple 80 dollar Bosch Plastic recirc. bov you cannot hear. Or Kimmos electric jobbie, or a variety of other types!
How you dump the air is your own issue and yes, opinion is what counts there. Some like it loud, some like nothing at all. You like dose, flutter and whatnot "fulli shiiiick mayyyte", cool for you. I hate it personally. Altho I can put up with that quiet and businesslike "sigh" some valves make.
Opinions and we are entitled to them no question/no dispute.
But from a technical standpoint, the facts cannot be disputed.
You interrupt the stable and laminar airflow, sufficiently over a compressor/turbine wheel rotating at extreme speed due to either 1: Stalling or 2: Surging it, sudden and catastrophic failure can be the result. massively increased wear and component fatigue at least
Listen to the news. If a jet aircraft engine suffers a compressor surge, (happened just recently, Jetstar I think) the engine is immediately shut down and it is removed and totally rebuilt.
As an ex aircraft maintenance engineer, I have fitted a brand spanking new JT-9 to a 747, seen it given a quick ground run, heard it "burp" (surge) on ground test and had to change the bloody thing for another new one.
You experience much the same destructive event EVERYTIME you change gears in a non bov fitted turbo car!!! It just so happens that the relative structural integrity of a humble turbo is perhaps (and happily) millions of times in excess of a commercial jet engine.
To remove, or at very least reduce that possibility of either stalling or surging (cavitation) with the addition of a bov cannot be argued M8.
The bov needs to be big enough of course.
Run this rationale by your technical gurus and lets see them debunk it.
well dont bother, they cant.
L8tr
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