somebody who knows a lot about turbos please help
 

YouTube - GTM 370Z TWIN TURBO WITH GTM 500

was that BOV fluttering i'm hearing? Is that a good thing or bad, because from what i understand is that the BOV fluttering is related to the turbo surging, which is bad. Experts please jump in to explain. Thanks.

That is the sound of compressor surge. A different blow off valve or bypass valve can aid this situation. When I switched to my Synapse BOV, my compressor surge completely went away.

Although in the video, I didn't hear it as much when driven on the street...

Yes, that is slight surge heard as the BOV fluttering. It's not really that bad for the compressor - what is bad is compressor surge that occurs under load when the turbo outspools/outflows the flow capacity of the engine at a particular RPM. This happens a lot with stock-housing turbos on the Evo when you mess with cam timing to improve spool up.

I'm guessing 370Z's need a BOV like the Synapse since we don't have a lot (if any) vacuum available when you transition from WOT to off-throttle. This is due to the inherent throttle body behavior in the VVEL-equipped engine (butterfly valves are almost always open while the engine is running).

So it's not too big a problem?

seems like it only happens at low rpm, at high rpm there that wosh sound. Is it because at low rpm because the engine has low vacuum, it's not stong enough to pull opne the BOV? If it's only happen at low rpm, it can't be that bad for the turbos right? Am I on the right track?

It's not a big problem. Don't lose sleep over it :)

Like Warm&SCSI mentioned the kind that's bad is high load\RPM surging.

It could also come from having too strong of an internal spring within the BOV as it will not release the diaphram and let positive pressure within the piping escape at part throttle which is not great for your turbos.

Its because the 370 is not pushing enough psi to fully open the BOV. Trust me dude, the kit is made perfect and engine runs like it came from the factory this way. Trust me.:tiphat:

thanks guys, 3 more months, I will be able to go TT. Counting down the days.

I've ordered a TT setup from GTM for my G37 Sport. My experience with the Synapse echoes what they said ^^^^.

Mine will have (2) Synchronic recirculated BOV's.

Although that flutter won't hurt anything, it affects low-throttle/boost let-off and is annoying at best.

Coop

Great turbocharger systems will utilize the pressure differential between the manifold and inlet pipe to actuate the blow-off valve. I'm not sure about the GTM setup, so I don't know if this is how they are set up. Can someone speak to this for GTM's kit?

Sounds like you are waiting for tax return hahaha.

:icon18: tax return, haha, that's funny, i will be happy if I don't owe anything:happydance:

Hahaha I feel ya, I will prolly owe money too. They screw the ones that make money and give it to the one that dont. I guess its ok just as long as I am still free at the end of the day ;)

yeah, you want be either make a lot of money or make little money, the guys that are in the middle got screwed the most. (aka most people)