Thread: post EVO vids here...

Just to quickly touch on "compressor surge," which is actually better described as flutter-dump in this particular instance. There's a lot of scattered information in this thread that collectively explains it, but not quite clearly, since there are two varieties.

First and foremost, this is what dangerous compressor surge is and sounds like:



That's the kind that you definitely do not want to experience and is destructive to turbos. It has more to do with the efficiency of the compressor wheel to flow a certain amount of air at a given rpm and what happens when that ratio is exceeded.

Now, this is more what's being discussed here, and it's not nearly as harmful to turbos, especially modern ones with lightweight compressor wheels and ball-bearing center cartridges. Watch with a grain of salt, it is a marketing video for Synapse.



The "squirrels" are simply a BOV that's adjusted too tightly or lack of a BOV entirely, as many rally cars run. When the throttle plate closes, the spring tension in the BOV is too stiff for the intake manifold vacuum to overcome so it doesn't open entirely and you get chatter.

thanks!

Originally Posted by Turbology

Just to quickly touch on "compressor surge," which is actually better described as flutter-dump in this particular instance. There's a lot of scattered information in this thread that collectively explains it, but not quite clearly, since there are two varieties.

First and foremost, this is what dangerous compressor surge is and sounds like:



That's the kind that you definitely do not want to experience and is destructive to turbos. It has more to do with the efficiency of the compressor wheel to flow a certain amount of air at a given rpm and what happens when that ratio is exceeded.

Now, this is more what's being discussed here, and it's not nearly as harmful to turbos, especially modern ones with lightweight compressor wheels and ball-bearing center cartridges. Watch with a grain of salt, it is a marketing video for Synapse.



The "squirrels" are simply a BOV that's adjusted too tightly or lack of a BOV entirely, as many rally cars run. When the throttle plate closes, the spring tension in the BOV is too stiff for the intake manifold vacuum to overcome so it doesn't open entirely and you get chatter.

Thanks you!! I feel like I always have to explain that on every forum I'm on. lol

Originally Posted by KandyRedCoi

thanks!

Originally Posted by Pushn'lbs

Thanks you!! I feel like I always have to explain that on every forum I'm on. lol

My pleasure, this was a public boost service announcement. And for those of you who like the "squirrels"...

And just to follow up, the generalized internet consensus seems to be that flutter is BAD, but quite honestly, with modern turbo designs, it's not really relevant.

That may have been the case on older turbos with outdated technology in the center sections, but lightweight, billet compressor wheels and multiple ball bearings go a long way to negate it.

Also, a race car running high boost frequently versus a daily driver at high boost occasionally are two different scenarios. Yes, it can be damaging under consistent stress, but not really otherwise.