What is Compressor Surge? - Explanation Within

[Tony D]

And, uh, no the diesel doesn't have a throttle plate. Acceleration is by injection fuel pulse and timing alteration. Any "throttle plate" on a diesel is associated with an emergency stop phenomenon (cut off air supply to stop engine.)

 

This goes back to the recommendation that people not post guesses.

[BLOZ UP]

They are both surge, they both are the EXACT SAME phenomenon, that is what the problem is! Please quit confusing the terms, trying to split them into two conditions which are physically identical, or applying them improperly, you aren't doing anybody any good muddying the terms up using them improperly.

 

Oh ok. So, to correct my post:

 

Any noise you hear when shifting is because your turbo is flowing more air then your engine can use so you need to replace the turbo or port your head to flow more. Despite being caused by two completely different things we'll just lump it all together so Tony D can keep things going here.

[Tony D]

"because your turbo is flowing more air then your engine can use" ... " Despite being caused by two completely different things we'll just lump it all together"

 

To quote Andy Duffrein from The Shawshank Redemption: "How can you be so obtuse?"

 

Note phenomenon: flow exceeds consumption, pressure rises, pressure exceeds flow point sustainable for wheel speed present: reverse flow occurs. This is referred to as surge. It was explained that the two phenomenon of natural pressure surge and throttled surge use the EXACT SAME mechanisms to precipitate the surge event: to little flow for the pressure extant at wheel discharge. Regardless of WOT or Mid Speed, they ARE the same. (When you consider the fact that the diesel doesn't even HAVE a throttle plate to restrict flow, and that a dump valve simply opens dumping excess flow, the argument of the throttle plate closing causing rise quickly is partucularly entertaining, but...you said it, not I!) the wheel is simply over speeding and the dump (BOV, whatever) opens venting some flow keeping stable flow over the wheel...you hear it. That's not a surge. Put a gauge on it, see what actually happens, THEN make a determination...but back to the disconnect in understanding:

 

It's the same at WOT, PARTIAL THROTTLE, or any other time. When flow off the wheel is less than the. Minimum flow required for the pressure being produced, a surge occurs.

 

NOT that this is necessarily a surge, as explained previously the bypass valve (or waste gate) may simply be opening to relieve pressure and it's now become audible.

 

Just because you hear air rushing through a pipe doesn't mean it's surge/stall/reversal.

 

Christ Sakes, man, quit arguing your digging your own hole of ignorance deeper each time you post. Understand the semantics here...it's obvious you're not even trying. You're just butthurt for some reason over the correction of your use of improper terminology. Get over it and listen to what's being said and learn something. The reason the post was written was to help educate people like yourself who misunderstand the phenomenon and to help them get their heads wrapped around what is happening during a surge, and what can be done in terms of controls to prevent it.

Edited August 25, 2013 by Tony D

[BLOZ UP]

Ok, I see, you're saying it's not surge because of the mechanisms in place that prevent it from happening in the first place. Is that what all this flabbergasting is for? You could have just said that.

[Tony D]

Define what you are referring to...

Your phenomenon that you describe is surge, you are referring to it incorrectly.

 

On his diesel issue, most likely it is not, and was stated as such before you came in muddying he waters with improper definitions and misguided impressions of "when" surge occurs!

 

Like I said, this thread needs som cleaning up as trash has littered it.

[Tony D]

And "flabbergasting" being misused in such a context reveals now why you can't comprehend whats being said.